{"id":51897,"date":"2020-02-01T17:08:12","date_gmt":"2020-02-01T16:08:12","guid":{"rendered":"https:\/\/www.thermal-engineering.org\/o-que-e-fluxo-de-fluido-bifasico-definicao\/"},"modified":"2020-02-01T17:25:48","modified_gmt":"2020-02-01T16:25:48","slug":"o-que-e-fluxo-de-fluido-bifasico-definicao","status":"publish","type":"post","link":"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-de-fluido-bifasico-definicao\/","title":{"rendered":"O que \u00e9 fluxo de fluido bif\u00e1sico &#8211; defini\u00e7\u00e3o"},"content":{"rendered":"<div class=\"su-quote su-quote-style-default\">\n<div class=\"su-quote-inner su-clearfix\">Por defini\u00e7\u00e3o, o fluxo bif\u00e1sico \u00e9 o fluxo interativo de duas fases distintas com interfaces comuns em, por exemplo, um condu\u00edte.\u00a0Fluxo de fluido bif\u00e1sico &#8211; fluxo g\u00e1s-l\u00edquido.\u00a0Engenharia T\u00e9rmica<\/div>\n<\/div>\n<div><\/div>\n<div><\/div>\n<div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<h2><span>Fluxo de fluido bif\u00e1sico<\/span><\/h2>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-fluid-flow.png\"><img loading=\"lazy\" class=\"alignright size-full wp-image-14768 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-fluid-flow.png\" alt=\"fluxo de fluido bif\u00e1sico\" width=\"82\" height=\"332\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-fluid-flow.png\" \/><\/a><span>Por defini\u00e7\u00e3o, o\u00a0<\/span><strong><span>fluxo multif\u00e1sico<\/span><\/strong><span>\u00a0\u00e9 o fluxo interativo de\u00a0<\/span><strong><span>duas ou mais<\/span><\/strong><span>\u00a0fases distintas com interfaces comuns em, por exemplo, um condu\u00edte.\u00a0Cada fase, representando uma fra\u00e7\u00e3o de volume (ou fra\u00e7\u00e3o de massa) de mat\u00e9ria s\u00f3lida, l\u00edquida ou gasosa,\u00a0<\/span><strong><span>possui<\/span><\/strong><span>\u00a0propriedades,\u00a0<\/span><strong><span>velocidade<\/span><\/strong><span>\u00a0e\u00a0<\/span><strong><span>temperatura\u00a0<\/span><\/strong><span><strong>pr\u00f3prias<\/strong>\u00a0.<\/span><\/p>\n<p><span>Um fluxo multif\u00e1sico pode ser fluxo simult\u00e2neo de:<\/span><\/p>\n<ul>\n<li><span>Materiais com\u00a0<\/span><strong><span>diferentes estados ou fases<\/span><\/strong><span>\u00a0(por exemplo, mistura \u00e1gua-vapor).<\/span><\/li>\n<li><span>Materiais com\u00a0<\/span><strong><span>propriedades qu\u00edmicas diferentes,<\/span><\/strong><span>\u00a0mas no mesmo estado ou fase (por exemplo, got\u00edculas de \u00f3leo na \u00e1gua).<\/span><\/li>\n<\/ul>\n<p><span>Existem muitas combina\u00e7\u00f5es nos processos industriais, mas a\u00a0<\/span><strong><span>mais comum<\/span><\/strong><span>\u00a0\u00e9 o fluxo simult\u00e2neo de\u00a0<\/span><strong><span>vapor e \u00e1gua l\u00edquida<\/span><\/strong><span>\u00a0(como encontrado em\u00a0<\/span><a title=\"Gerador de vapor\" href=\"https:\/\/www.nuclear-power.com\/steam-generator\/\"><strong><span>geradores<\/span><\/strong>\u00a0<\/a><span>e\u00a0<\/span><strong><span>condensadores de\u00a0<\/span><\/strong><span><a title=\"Gerador de vapor\" href=\"https:\/\/www.nuclear-power.com\/steam-generator\/\"><strong>vapor<\/strong><\/a>\u00a0).\u00a0Na engenharia de reatores, muitos estudos foram realizados sobre a natureza do\u00a0<\/span><strong><span>fluxo bif\u00e1sico<\/span><\/strong><span>\u00a0em caso de acidente com perda de l\u00edquido refrigerante (\u00a0<\/span><strong><span>LOCA<\/span><\/strong><span>\u00a0), que \u00e9 um acidente de import\u00e2ncia na seguran\u00e7a do reator e em todas as an\u00e1lises termo-hidr\u00e1ulicas (\u00a0<\/span><strong><span>An\u00e1lises DNBR<\/span><\/strong><span>\u00a0).<\/span><\/p>\n<p>&nbsp;<\/p>\n<h2><span>Caracter\u00edsticas do fluxo de fluido bif\u00e1sico<\/span><\/h2>\n<p><span>Todos os problemas de fluxo de duas fases t\u00eam caracter\u00edsticas que s\u00e3o caracteristicamente diferentes daquelas encontradas em problemas de fase \u00fanica.<\/span><\/p>\n<ul>\n<li><span>No caso de vapor e \u00e1gua l\u00edquida, a\u00a0<\/span><strong><span>densidade<\/span><\/strong><span>\u00a0das duas fases\u00a0<\/span><strong><span>difere por um fator de cerca de 1000<\/span><\/strong><span>\u00a0.\u00a0Portanto, a influ\u00eancia da for\u00e7a do corpo gravitacional nos fluxos multif\u00e1sicos \u00e9 de muito maior import\u00e2ncia do que no caso dos fluxos monof\u00e1sicos.<\/span><\/li>\n<li><span>A\u00a0<\/span><strong><span>velocidade do som<\/span><\/strong><span>\u00a0muda drasticamente para os materiais em fase de mudan\u00e7a e pode ter ordens de magnitude diferentes.\u00a0Isso influencia significativamente um\u00a0<\/span><strong><span>fluxo atrav\u00e9s de um orif\u00edcio<\/span><\/strong><span>\u00a0.<\/span><\/li>\n<li><span>A\u00a0<\/span><strong><span>concentra\u00e7\u00e3o<\/span><\/strong><span>\u00a0relativa\u00a0de diferentes fases \u00e9 geralmente um par\u00e2metro dependente de grande import\u00e2ncia nos fluxos multif\u00e1sicos, enquanto \u00e9 um par\u00e2metro sem conseq\u00fc\u00eancia nos fluxos monof\u00e1sicos.<\/span><\/li>\n<li><span>A mudan\u00e7a de fase significa que as quedas de press\u00e3o induzidas pelo fluxo podem causar altera\u00e7\u00f5es de fase adicionais (por exemplo, a \u00e1gua pode evaporar atrav\u00e9s de um orif\u00edcio), aumentando o volume relativo do meio gasoso, compress\u00edvel e aumentando as velocidades de efluxo, diferentemente do fluxo incompress\u00edvel monof\u00e1sico, em que a diminui\u00e7\u00e3o de um orif\u00edcio diminuiria a velocidade do efluxo.<\/span><\/li>\n<li><span>A distribui\u00e7\u00e3o espacial das v\u00e1rias fases no canal de fluxo afeta fortemente o comportamento do fluxo.<\/span><\/li>\n<li><span>Existem muitos tipos de instabilidades no fluxo multif\u00e1sico.<\/span><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>Par\u00e2metros b\u00e1sicos do fluxo de fluido em duas fases<\/span><\/h2>\n<p><span>Nesta se\u00e7\u00e3o, consideraremos o fluxo simult\u00e2neo de\u00a0<\/span><strong><span>g\u00e1s (ou vapor) e \u00e1gua l\u00edquida<\/span><\/strong><span>\u00a0(como encontrado em\u00a0<\/span><a title=\"Gerador de vapor\" href=\"https:\/\/www.nuclear-power.com\/steam-generator\/\"><span>geradores<\/span><\/a><span>\u00a0e condensadores de\u00a0<a title=\"Gerador de vapor\" href=\"https:\/\/www.nuclear-power.com\/steam-generator\/\">vapor<\/a>\u00a0) no fluxo simult\u00e2neo atrav\u00e9s de um duto com \u00e1rea de se\u00e7\u00e3o transversal A. Os subscritos\u00a0<\/span><strong><span>\u201cv\u201d<\/span><\/strong><span>\u00a0e\u00a0<\/span><strong><span>\u201c\u2113\u201d<\/span><\/strong><span>\u00a0indicam a\u00a0fase\u00a0<\/span><strong><span>vapor<\/span><\/strong><span>\u00a0e\u00a0<\/span><strong><span>a<\/span><\/strong><span>\u00a0fase\u00a0<strong>l\u00edquida<\/strong>\u00a0, respectivamente.\u00a0Os par\u00e2metros fundamentais que caracterizam esse fluxo s\u00e3o:<\/span><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-accordion\">\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\">\n<ul>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><span>Fra\u00e7\u00e3o de vazio<\/span><\/li>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\">Qualidade est\u00e1tica<\/li>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\">Qualidade do fluxo<\/li>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\">Densidade da mistura<\/li>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\">Taxa de escorregamento &#8211; Taxa de velocidade<\/li>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\">Velocidade superficial<\/li>\n<\/ul>\n<\/div>\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\">\n<div class=\"su-spoiler-content su-clearfix\">\n<p>&nbsp;<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<h2><span>Padr\u00f5es de fluxo &#8211; fluxo bif\u00e1sico<\/span><\/h2>\n<p><span>Um dos aspectos mais desafiadores de lidar com o\u00a0<\/span><strong><span>fluxo bif\u00e1sico ou multif\u00e1sico<\/span><\/strong><span>\u00a0\u00e9 o fato de que ele pode assumir\u00a0<\/span><strong><span>muitas formas diferentes<\/span><\/strong><span>\u00a0.\u00a0<\/span><strong><span>As distribui\u00e7\u00f5es espaciais e as velocidades<\/span><\/strong><span>\u00a0das\u00a0<\/span><strong><span>fases l\u00edquida e de vapor<\/span><\/strong><span>\u00a0no canal de fluxo s\u00e3o aspectos muito importantes em muitos ramos da engenharia.\u00a0<\/span><strong><span>Quedas de press\u00e3o<\/span><\/strong><span>\u00a0e tamb\u00e9m\u00a0<\/span><strong><span>coeficientes de transfer\u00eancia de calor<\/span><\/strong><span>\u00a0dependem fortemente da\u00a0<\/span><strong><span>estrutura do fluxo local<\/span><\/strong><span>\u00a0e, portanto, \u00e9 importante na engenharia de\u00a0<\/span><a title=\"Reator nuclear\" href=\"https:\/\/www.nuclear-power.com\/nuclear-power-plant\/nuclear-reactor\/\"><strong><span>reatores nucleares<\/span><\/strong><\/a><span>\u00a0.\u00a0As estruturas de fluxo observadas s\u00e3o definidas como\u00a0<\/span><strong><span>padr\u00f5es de fluxo bif\u00e1sicos<\/span><\/strong><span>\u00a0e possuem caracter\u00edsticas de identifica\u00e7\u00e3o particulares.\u00a0Esses diferentes padr\u00f5es de fluxo foram<\/span><strong><span>categorizados de<\/span><\/strong><span>\u00a0acordo com a\u00a0<\/span><strong><span>dire\u00e7\u00e3o do fluxo em<\/span><\/strong><span>\u00a0rela\u00e7\u00e3o \u00e0 acelera\u00e7\u00e3o gravitacional.<\/span><\/p>\n<ul>\n<li><strong><span>Padr\u00f5es de fluxo em tubos verticais<\/span><\/strong><\/li>\n<li><strong><span>Padr\u00f5es de fluxo em tubos horizontais<\/span><\/strong><\/li>\n<\/ul>\n<figure id=\"attachment_14848\" class=\"wp-caption alignright\" aria-describedby=\"caption-attachment-14848\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/flow-patterns-table.png\"><img loading=\"lazy\" class=\"size-medium wp-image-14848 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/flow-patterns-table-300x198.png\" alt=\"padr\u00f5es de fluxo\" width=\"300\" height=\"198\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/flow-patterns-table-300x198.png\" \/><\/a><figcaption id=\"caption-attachment-14848\" class=\"wp-caption-text\"><span>Tabela de padr\u00f5es b\u00e1sicos de fluxo em tubos verticais.<\/span><\/figcaption><\/figure>\n<p><span>Os principais regimes de fluxo\u00a0<\/span><strong><span>em tubos verticais<\/span><\/strong><span>\u00a0s\u00e3o mostrados na tabela.\u00a0Deve-se observar que os valores de\u00a0<\/span><a title=\"Qualidade est\u00e1tica - Qualidade do fluxo\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/two-phase-fluid-flow\/static-quality-flow-quality\/\"><strong><span>qualidade<\/span><\/strong>\u00a0<\/a><span>e\u00a0<\/span><strong><span>vaz\u00e3o<\/span><\/strong><span>\u00a0dependem do fluido e da press\u00e3o.\u00a0<\/span><strong><span>Nos tubos horizontais<\/span><\/strong><span>\u00a0, tamb\u00e9m pode haver\u00a0<\/span><strong><span>fluxo estratificado<\/span><\/strong><span>\u00a0(especialmente em vaz\u00f5es baixas), nas quais as duas fases se\u00a0<\/span><strong><span>separam<\/span><\/strong><span>\u00a0sob o efeito da gravidade.<\/span><\/p>\n<p><span>Para uma vaz\u00e3o constante de l\u00edquido, a fase de vapor \/ g\u00e1s tende a ser distribu\u00edda como\u00a0<\/span><strong><span>pequenas bolhas<\/span><\/strong><span>\u00a0a baixas vaz\u00f5es de vapor.\u00a0<\/span><strong><span>O aumento da fra\u00e7\u00e3o de vazios<\/span><\/strong><span>\u00a0causa\u00a0<\/span><strong><span>aglomera\u00e7\u00e3o<\/span><\/strong><span>\u00a0de bolhas em\u00a0<\/span><strong><span>plugues e lesmas maiores<\/span><\/strong><span>\u00a0.\u00a0A aglomera\u00e7\u00e3o adicional de lesmas, causada pelo\u00a0<\/span><strong><span>aumento da fra\u00e7\u00e3o de vazio,<\/span><\/strong><span>\u00a0causa a separa\u00e7\u00e3o das fases em\u00a0<\/span><strong><span>padr\u00f5es anulares,<\/span><\/strong><span>\u00a0em que o l\u00edquido se concentra na parede do canal e o\u00a0<\/span><strong><span>vapor flui no n\u00facleo central<\/span><\/strong><span>\u00a0do canal vertical.<\/span><\/p>\n<p><strong><span>Para o canal horizontal<\/span><\/strong><span>\u00a0, a for\u00e7a gravitacional tende a drenar o anel l\u00edquido em dire\u00e7\u00e3o \u00e0 parte inferior do canal, resultando em\u00a0<\/span><strong><span>fluxo estratificado<\/span><\/strong><span>\u00a0.\u00a0A for\u00e7a gravitacional que atua na fase l\u00edquida pode ser superada por for\u00e7as cin\u00e9ticas a altas taxas de fluxo, fazendo com que fluxos estratificados voltem a fluxos anulares.\u00a0<\/span><strong><span>Em vaz\u00f5es muito altas<\/span><\/strong><span>\u00a0, o filme anular \u00e9 dilu\u00eddo pelo cisalhamento do n\u00facleo de vapor e todo o l\u00edquido \u00e9 arrastado como got\u00edculas na fase de vapor.\u00a0Esse regime de fluxo \u00e9 geralmente conhecido como\u00a0<\/span><strong><span>fluxo de n\u00e9voa<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><span>Veja tamb\u00e9m:\u00a0\u00a0<\/span><strong><span>Livro de Dados de Engenharia III, Thome, JR, Wolverine Tube Inc, 2004.<\/span><\/strong><\/p>\n<div class=\"su-spacer\"><\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-50 lgc-tablet-grid-50 lgc-mobile-grid-100 lgc-equal-heights  lgc-first\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>Padr\u00f5es de Fluxo &#8211; Tubos Verticais<\/span><\/h2>\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\">\n<ul>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><span>Fluxo borbulhante<\/span><\/li>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\">Fluxo de lesmas<\/li>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\">Fluxo de rotatividade<\/li>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\">Fluxo anular<\/li>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\">Fluxo de n\u00e9voa<\/li>\n<\/ul>\n<\/div>\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\">\n<div class=\"su-spoiler-content su-clearfix\"><\/div>\n<\/div>\n<div class=\"su-divider su-divider-style-dotted\"><\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-50 lgc-tablet-grid-50 lgc-mobile-grid-100 lgc-equal-heights  lgc-last\">\n<div class=\"inside-grid-column\">\n<figure id=\"attachment_14791\" class=\"wp-caption alignleft\" aria-describedby=\"caption-attachment-14791\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Bubbly-Slug-Churn-Annular-Mist-Flow.png\"><img loading=\"lazy\" class=\"wp-image-14791 size-medium lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Bubbly-Slug-Churn-Annular-Mist-Flow-300x191.png\" alt=\"Borbulhante - Lesma - Batedeira - Anular - N\u00e9voa - Fluxo\" width=\"300\" height=\"191\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Bubbly-Slug-Churn-Annular-Mist-Flow-300x191.png\" \/><\/a><figcaption id=\"caption-attachment-14791\" class=\"wp-caption-text\"><span>Esbo\u00e7os de regimes de fluxo para fluxo bif\u00e1sico em um tubo vertical.\u00a0Fonte: Weisman, J. Padr\u00f5es de fluxo bif\u00e1sicos.\u00a0Cap\u00edtulo 15 do Manual de Fluidos em Movimento, Cheremisinoff NP, Gupta R. 1983, Ann Arbor Science Publishers.<\/span><\/figcaption><\/figure>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<figure id=\"attachment_14788\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-14788\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/flow-patterns-vertical-flow-Hewitt.png\"><img loading=\"lazy\" class=\"wp-image-14788 size-full lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/flow-patterns-vertical-flow-Hewitt.png\" alt=\"padr\u00f5es de fluxo - fluxo vertical - Hewitt\" width=\"428\" height=\"397\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/flow-patterns-vertical-flow-Hewitt.png\" \/><\/a><figcaption id=\"caption-attachment-14788\" class=\"wp-caption-text\"><span>O mapa do regime de fluxo vertical de Hewitt e Roberts (1969) para fluxo em um tubo de 3,2 cm de di\u00e2metro, validado para fluxo de ar \/ \u00e1gua \u00e0 press\u00e3o atmosf\u00e9rica e fluxo de vapor \/ \u00e1gua a alta press\u00e3o.\u00a0Fonte: Brennen, CE, Fundamentos de fluxos multif\u00e1sicos, Cambridge University Press, 2005, ISBN 0521 848040<\/span><\/figcaption><\/figure>\n<div class=\"su-spacer\"><\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-50 lgc-tablet-grid-50 lgc-mobile-grid-100 lgc-equal-heights  lgc-first\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>Padr\u00f5es de Fluxo &#8211; Tubos Horizontais<\/span><\/h2>\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\">\n<ul>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><span>Fluxo borbulhante<\/span><\/li>\n<\/ul>\n<\/div>\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\">\n<ul>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><span>Fluxo estratificado<\/span><\/li>\n<\/ul>\n<\/div>\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\">\n<ul>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><span>Fluxo da tomada e fluxo da lesma<\/span><\/li>\n<\/ul>\n<\/div>\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\">\n<ul>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><span>Fluxo anular<\/span><\/li>\n<\/ul>\n<\/div>\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\">\n<ul>\n<li class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><span>Fluxo de n\u00e9voa<\/span><\/li>\n<\/ul>\n<div class=\"su-spoiler-content su-clearfix\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-50 lgc-tablet-grid-50 lgc-mobile-grid-100 lgc-equal-heights  lgc-last\">\n<div class=\"inside-grid-column\">\n<figure id=\"attachment_14790\" class=\"wp-caption alignleft\" aria-describedby=\"caption-attachment-14790\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Bubbly-Slug-Plug-Annular-Stratified-Mist-Wavy.png\"><img loading=\"lazy\" class=\"wp-image-14790 size-medium lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Bubbly-Slug-Plug-Annular-Stratified-Mist-Wavy-300x252.png\" alt=\"bolha, plug, lesma, anular, n\u00e9voa, fluxo estratificado ou ondulado\" width=\"300\" height=\"252\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Bubbly-Slug-Plug-Annular-Stratified-Mist-Wavy-300x252.png\" \/><\/a><figcaption id=\"caption-attachment-14790\" class=\"wp-caption-text\"><span>Esbo\u00e7os de regimes de fluxo para fluxo bif\u00e1sico em um tubo horizontal.\u00a0Fonte: Weisman, J. Padr\u00f5es de fluxo bif\u00e1sicos.\u00a0Cap\u00edtulo 15 do Manual de Fluidos em Movimento, Cheremisinoff NP, Gupta R. 1983, Ann Arbor Science Publishers.<\/span><\/figcaption><\/figure>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<figure id=\"attachment_14789\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-14789\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/flow-patterns-horizontal-flow.png\"><img loading=\"lazy\" class=\"wp-image-14789 size-full lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/flow-patterns-horizontal-flow.png\" alt=\"padr\u00f5es de fluxo - fluxo horizontal\" width=\"436\" height=\"416\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/flow-patterns-horizontal-flow.png\" \/><\/a><figcaption id=\"caption-attachment-14789\" class=\"wp-caption-text\"><span>Um mapa de regime de fluxo para o fluxo de uma mistura ar \/ \u00e1gua em um tubo horizontal de 2,5 cm de di\u00e2metro a 25 \u00b0 C e 1 bar.\u00a0Linhas e pontos s\u00f3lidos s\u00e3o observa\u00e7\u00f5es experimentais das condi\u00e7\u00f5es de transi\u00e7\u00e3o, enquanto as zonas tracejadas representam previs\u00f5es te\u00f3ricas.\u00a0Fonte: Mandhane, JM, Gregory, GA e Aziz, KA (1974).\u00a0Um mapa de padr\u00f5es de fluxo para fluxo g\u00e1s-l\u00edquido em tubos horizontais.\u00a0Int.\u00a0J. Fluxo multif\u00e1sico<\/span><\/figcaption><\/figure>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>Padr\u00f5es de fluxo durante a evapora\u00e7\u00e3o<\/span><\/h2>\n<p><span>A se\u00e7\u00e3o anterior descreve v\u00e1rios\u00a0<\/span><strong><span>padr\u00f5es de fluxo<\/span><\/strong><span>\u00a0e descreve brevemente seu comportamento.\u00a0Esses padr\u00f5es de fluxo foram considerados\u00a0<\/span><strong><span>em fra\u00e7\u00e3o de vazio constante<\/span><\/strong><span>\u00a0e\u00a0<\/span><strong><span>em velocidades superficiais constantes<\/span><\/strong><span>\u00a0.\u00a0Mas existem muitas aplica\u00e7\u00f5es industriais que precisam considerar uma\u00a0<\/span><strong><span>fra\u00e7\u00e3o de vazio<\/span><\/strong><span>\u00a0vari\u00e1vel e velocidades superficiais vari\u00e1veis.\u00a0Na ind\u00fastria nuclear, temos que lidar com os padr\u00f5es de fluxo durante a\u00a0<\/span><strong><span>evapora\u00e7\u00e3o<\/span><\/strong><span>\u00a0(isto \u00e9, durante mudan\u00e7as na\u00a0<\/span><a title=\"Fra\u00e7\u00e3o de Vazio - Fluxo de Duas Fases\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/two-phase-fluid-flow\/void-fraction-two-phase-flow\/\"><span>fra\u00e7\u00e3o de vazio<\/span><\/a><span>\u00a0).<\/span><\/p>\n<p><span>O conhecimento detalhado das\u00a0<\/span><strong><span>mudan\u00e7as<\/span><\/strong><span>\u00a0de\u00a0<strong>fase<\/strong>\u00a0e o comportamento do fluxo durante a mudan\u00e7a de fase \u00e9 uma das considera\u00e7\u00f5es mais importantes no projeto de um\u00a0<\/span><a title=\"Reator nuclear\" href=\"https:\/\/www.nuclear-power.com\/nuclear-power-plant\/nuclear-reactor\/\"><strong><span>reator nuclear<\/span><\/strong><\/a><span>\u00a0, especialmente nas seguintes aplica\u00e7\u00f5es:<\/span><\/p>\n<ul>\n<li><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/convective-evaporation-vertical-channel-fig.png\"><img loading=\"lazy\" class=\"alignright size-full wp-image-14854 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/convective-evaporation-vertical-channel-fig.png\" alt=\"evapora\u00e7\u00e3o convectiva - canal vertical\" width=\"262\" height=\"633\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/convective-evaporation-vertical-channel-fig.png\" \/><\/a><a title=\"BWR - Reator de \u00e1gua fervente\" href=\"https:\/\/www.nuclear-power.com\/bwr-boiling-water-reactor\/\"><span>BWR &#8211; Reatores de \u00e1gua fervente<\/span><\/a>\n<ul>\n<li><span>Um\u00a0<\/span><strong><span>reator de \u00e1gua fervente<\/span><\/strong><span>\u00a0\u00e9 resfriado e\u00a0<\/span><a title=\"Moderador de n\u00eautrons\" href=\"https:\/\/www.nuclear-power.com\/neutron-moderator\/\"><span>moderado<\/span><\/a><span>\u00a0por \u00e1gua como um PWR, mas a uma\u00a0<\/span><strong><span>press\u00e3o mais baixa<\/span><\/strong><span>\u00a0(7MPa), que permite que a \u00e1gua\u00a0<\/span><strong><span>ferva dentro do vaso de press\u00e3o<\/span><\/strong><span>\u00a0produzindo o vapor que aciona as turbinas.\u00a0Portanto, a evapora\u00e7\u00e3o ocorre diretamente nos canais de combust\u00edvel.\u00a0Portanto, os BWRs s\u00e3o o melhor exemplo para esta \u00e1rea, porque a evapora\u00e7\u00e3o do l\u00edquido refrigerante ocorre na opera\u00e7\u00e3o normal e \u00e9 um fen\u00f4meno muito desejado.<\/span><\/li>\n<li><span>Nos BWRs, h\u00e1 um fen\u00f4meno que \u00e9 da\u00a0<\/span><strong><span>maior import\u00e2ncia na seguran\u00e7a do reator<\/span><\/strong><span>\u00a0.\u00a0Esse fen\u00f4meno \u00e9 conhecido como\u00a0<\/span><strong><span>\u201cseca\u201d<\/span><\/strong><span>\u00a0e est\u00e1 diretamente associado a\u00a0<\/span><strong><span>altera\u00e7\u00f5es no padr\u00e3o de fluxo<\/span><\/strong><span>\u00a0durante a evapora\u00e7\u00e3o.\u00a0Normalmente, a superf\u00edcie do combust\u00edvel \u00e9 efetivamente resfriada com l\u00edquido de ebuli\u00e7\u00e3o fervente.\u00a0No entanto, quando o fluxo de calor excede um\u00a0<\/span><strong><span>valor cr\u00edtico<\/span><\/strong><span>\u00a0(CHF &#8211; fluxo de calor cr\u00edtico), o padr\u00e3o de fluxo pode atingir as\u00a0<\/span><strong><span>condi\u00e7\u00f5es de secagem<\/span><\/strong><span>\u00a0(a pel\u00edcula fina de l\u00edquido desaparece).\u00a0A transfer\u00eancia de calor da superf\u00edcie do combust\u00edvel para o refrigerante \u00e9 deteriorada, com o resultado de um\u00a0<\/span><strong><span>aumento dr\u00e1stico da temperatura da superf\u00edcie do combust\u00edvel<\/span><\/strong><span>\u00a0.<\/span><\/li>\n<\/ul>\n<\/li>\n<li><a title=\"PWR - Reator de \u00e1gua pressurizada\" href=\"https:\/\/www.nuclear-power.com\/pwr-pressurized-water-reactor\/\"><span>PWR &#8211; Reatores de \u00e1gua pressurizada<\/span><\/a>\n<ul>\n<li><span>Em\u00a0<\/span><strong><span>PWRs<\/span><\/strong><span>\u00a0em\u00a0<\/span><strong><span>opera\u00e7\u00e3o normal,<\/span><\/strong><span>\u00a0o fluxo \u00e9 considerado monof\u00e1sico.\u00a0Por\u00e9m, muitos estudos foram realizados sobre a natureza do\u00a0<\/span><strong><span>fluxo bif\u00e1sico<\/span><\/strong><span>\u00a0em caso de\u00a0<\/span><strong><span>transientes e acidentes<\/span><\/strong><span>\u00a0(como o\u00a0<strong>acidente<\/strong>\u00a0com\u00a0<\/span><strong><span>perda de l\u00edquido refrigerante &#8211; LOCA ou disparo de RCPs<\/span><\/strong><span>\u00a0), que s\u00e3o importantes para a seguran\u00e7a do reator e deve ser comprovado e declarado no\u00a0<\/span><strong><span>Relat\u00f3rio de An\u00e1lise de Seguran\u00e7a<\/span><\/strong><span>\u00a0(SAR).\u00a0No caso de PWRs, o fen\u00f4meno problem\u00e1tico n\u00e3o \u00e9 a seca.\u00a0No caso de PWRs, o fluxo cr\u00edtico \u00e9 o\u00a0<\/span><strong><span>fluxo anular invertido<\/span><\/strong><span>\u00a0.\u00a0Esse fluxo ocorre quando uma superf\u00edcie de revestimento da barra de combust\u00edvel \u00e9 superaquecida, o que causa a forma\u00e7\u00e3o de uma\u00a0<\/span><strong><span>camada de vapor local<\/span><\/strong><span>, causando uma redu\u00e7\u00e3o dr\u00e1stica na capacidade de transfer\u00eancia de calor.\u00a0Esse fen\u00f4meno \u00e9 conhecido como\u00a0<\/span><strong><span>afastamento da ebuli\u00e7\u00e3o nucleada &#8211; DNB<\/span><\/strong><span>\u00a0.\u00a0A diferen\u00e7a no regime de fluxo entre o fluxo p\u00f3s-secagem e o fluxo p\u00f3s-DNB \u00e9 mostrada na figura.<\/span><\/li>\n<li><span>Nos PWRs, a evapora\u00e7\u00e3o ocorre tamb\u00e9m em geradores de vapor.\u00a0Geradores de vapor s\u00e3o\u00a0<\/span><strong><span>trocadores de calor<\/span><\/strong><span>\u00a0usados \u200b\u200bpara converter\u00a0<\/span><strong><span>\u00e1gua de alimenta\u00e7\u00e3o em vapor a<\/span><\/strong><span>\u00a0partir do calor produzido no\u00a0<\/span><a href=\"https:\/\/www.reactor-physics.com\/what-is-reactor-core-definition\/\"><span>n\u00facleo de<\/span><\/a><span>\u00a0um\u00a0<a href=\"https:\/\/www.reactor-physics.com\/what-is-reactor-core-definition\/\">reator nuclear<\/a>\u00a0.\u00a0O vapor produzido aciona a turbina.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-accordion\">\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\">\n<div class=\"su-spoiler-content su-clearfix\"><\/div>\n<\/div>\n<\/div>\n<div class=\"su-divider su-divider-style-dotted\"><\/div>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/convective-evaporation-horizontal-channel-fig.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-14855 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/convective-evaporation-horizontal-channel-fig.png\" alt=\"evapora\u00e7\u00e3o por convec\u00e7\u00e3o - canal horizontal\" width=\"587\" height=\"226\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/convective-evaporation-horizontal-channel-fig.png\" \/><\/a><\/p>\n<div class=\"su-spacer\"><\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\"><\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<h2><span>Queda de press\u00e3o bif\u00e1sica<\/span><\/h2>\n<p><span>Na an\u00e1lise pr\u00e1tica de sistemas de tubula\u00e7\u00e3o, a quantidade mais importante \u00e9 a\u00a0<\/span><strong><span>perda de press\u00e3o devido a efeitos viscosos<\/span><\/strong><span>\u00a0ao longo do comprimento do sistema, bem como\u00a0<\/span><strong><span>perdas de press\u00e3o adicionais<\/span><\/strong><span>\u00a0decorrentes de outros\u00a0<\/span><strong><span>equipamentos tecnol\u00f3gicos<\/span><\/strong><span>\u00a0como v\u00e1lvulas, cotovelos, entradas de tubula\u00e7\u00e3o, conex\u00f5es e T .<\/span><\/p>\n<p><span>Ao contr\u00e1rio das quedas de press\u00e3o monof\u00e1sicas, o c\u00e1lculo e a previs\u00e3o de quedas de press\u00e3o bif\u00e1sicas s\u00e3o um problema muito mais sofisticado e os m\u00e9todos principais diferem significativamente.\u00a0Dados experimentais indicam que a\u00a0<\/span><strong><span>queda de press\u00e3o de atrito no fluxo bif\u00e1sico<\/span><\/strong><span>\u00a0(por exemplo, em um canal de ebuli\u00e7\u00e3o) \u00e9\u00a0<\/span><strong><span>substancialmente maior<\/span><\/strong><span>\u00a0do que no fluxo monof\u00e1sico com o mesmo comprimento e taxa de fluxo de massa.\u00a0As explica\u00e7\u00f5es para isso incluem um aparente aumento da rugosidade da superf\u00edcie devido \u00e0 forma\u00e7\u00e3o de bolhas na superf\u00edcie aquecida e maiores velocidades de fluxo.<\/span><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>Queda de Press\u00e3o &#8211; Modelo de Fluxo Homog\u00eaneo<\/span><\/h2>\n<p><span>A abordagem mais simples para a previs\u00e3o de fluxos bif\u00e1sicos \u00e9 tratar todo o fluxo bif\u00e1sico como se fosse\u00a0<\/span><strong><span>l\u00edquido<\/span><\/strong><span>\u00a0, exceto o fluxo na\u00a0<\/span><strong><span>velocidade da mistura<\/span><\/strong><span>\u00a0bif\u00e1sica\u00a0.\u00a0As quedas de press\u00e3o bif\u00e1sicas para fluxos dentro de tubula\u00e7\u00f5es e canais s\u00e3o a soma de tr\u00eas contribui\u00e7\u00f5es:<\/span><\/p>\n<ul>\n<li><span>a queda de press\u00e3o est\u00e1tica\u00a0<\/span><strong><span>staticp\u00a0<\/span><sub><span>est\u00e1tica<\/span><\/sub>\u00a0<\/strong><span>(\u00a0<\/span><a title=\"Cabe\u00e7a de eleva\u00e7\u00e3o\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/bernoullis-equation-bernoullis-principle\/elevation-head-2\/\"><span>cabe\u00e7a de eleva\u00e7\u00e3o<\/span><\/a><span>\u00a0)<\/span><\/li>\n<li><span>o momento de queda de press\u00e3o\u00a0<\/span><strong><span>momp\u00a0<\/span><sub><span>m\u00e3e<\/span><\/sub><\/strong><span>\u00a0(\u00a0<\/span><a title=\"Acelera\u00e7\u00e3o de Fluidos - Perda de Press\u00e3o\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/minor-head-loss-local-losses\/fluid-acceleration-pressure-loss\/\"><span>acelera\u00e7\u00e3o de fluidos<\/span><\/a><span>\u00a0)<\/span><\/li>\n<li><span>a queda de press\u00e3o de atrito\u00a0<\/span><strong><span>\u2206p\u00a0<\/span><sub><span>frito<\/span><\/sub><\/strong><\/li>\n<\/ul>\n<p><span>A queda de press\u00e3o total do fluxo bif\u00e1sico \u00e9 ent\u00e3o:<\/span><\/p>\n<p><strong><span>Totalp\u00a0<\/span><sub><span>total<\/span><\/sub><span>\u00a0= staticp\u00a0<\/span><sub><span>est\u00e1tico<\/span><\/sub><span>\u00a0+\u00a0<sub>momp\u00a0<\/sub><\/span><sub><span>m\u00e3e<\/span><\/sub><span>\u00a0+\u00a0<\/span><sub><span>frp frito<\/span><\/sub><\/strong><\/p>\n<p><span>As quedas de press\u00e3o est\u00e1ticas e de momento podem ser calculadas da mesma forma que no caso de fluxo monof\u00e1sico e usando a\u00a0<\/span><a title=\"Densidade da mistura - Fluxo bif\u00e1sico\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/two-phase-fluid-flow\/mixture-density-two-phase-flow\/\"><span>densidade<\/span><\/a><span>\u00a0homog\u00eanea da\u00a0<a title=\"Densidade da mistura - Fluxo bif\u00e1sico\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/two-phase-fluid-flow\/mixture-density-two-phase-flow\/\">mistura<\/a>\u00a0:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/mixture-density-definition.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-14774 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/mixture-density-definition.png\" alt=\"densidade da mistura - defini\u00e7\u00e3o\" width=\"312\" height=\"51\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/mixture-density-definition.png\" \/><\/a><\/p>\n<p><span>O termo mais problem\u00e1tica \u00e9 a\u00a0<\/span><strong><span>queda de press\u00e3o de atrito\u00a0<\/span><\/strong><strong><span>Ap\u00a0<\/span><sub><span>atrito contra a\u00e7o<\/span><\/sub><\/strong><span>\u00a0, o qual \u00e9 baseado na queda de press\u00e3o de fase \u00fanica que \u00e9 multiplicado pelo\u00a0<\/span><strong><span>factor de correc\u00e7\u00e3o de duas fases<\/span><\/strong><span>\u00a0(\u00a0<\/span><strong><span>de atrito homog\u00e9nea multiplicador &#8211; \u03a6\u00a0<\/span><sub><span>Lo\u00a0<\/span><\/sub><sup><span>2<\/span><\/sup><\/strong><span>\u00a0).\u00a0Por essa abordagem, o componente de atrito da queda de press\u00e3o bif\u00e1sica \u00e9:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-pressure-drop-equation.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-14901 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-pressure-drop-equation.png\" alt=\"queda de press\u00e3o bif\u00e1sica - equa\u00e7\u00e3o\" width=\"225\" height=\"68\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-pressure-drop-equation.png\" \/><\/a><\/p>\n<p><span>onde\u00a0<\/span><strong><span>(dP \/ dz)\u00a0<\/span><sub><span>2f<\/span><\/sub><\/strong><span>\u00a0\u00a0\u00e9 gradiente de press\u00e3o de atrito do fluxo bif\u00e1sico e\u00a0<\/span><strong><span>(dP \/ dz)\u00a0<\/span><sub><span>1f<\/span><\/sub><\/strong><span>\u00a0\u00a0\u00e9 gradiente de press\u00e3o de atrito se o fluxo inteiro (da taxa de fluxo de massa total G) fluir como l\u00edquido no canal (\u00a0<\/span><a title=\"Perda de Cabe\u00e7a Maior - Perda de Fric\u00e7\u00e3o\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/major-head-loss-friction-loss\/\"><span>press\u00e3o monof\u00e1sica padr\u00e3o gota<\/span><\/a><span>\u00a0).\u00a0O termo\u00a0<\/span><strong><span>\u03a6\u00a0<\/span><sub><span>lo\u00a0<\/span><\/sub><sup><span>2\u00a0<\/span><\/sup><\/strong><span>\u00a0\u00e9 o\u00a0<\/span><strong><span>multiplicador de atrito homog\u00eaneo<\/span><\/strong><span>\u00a0, que pode ser derivado de acordo com v\u00e1rios m\u00e9todos.\u00a0Um dos multiplicadores poss\u00edveis \u00e9 igual a\u00a0<\/span><strong><span>\u03a6\u00a0<\/span><sub><span>lo\u00a0<\/span><\/sub><sup><span>2<\/span><\/sup><span>\u00a0\u00a0= (1 + x\u00a0<\/span><sub><span>g<\/span><\/sub><span>\u00a0(\u03c1\u00a0<\/span><sub><span>l<\/span><\/sub><span>\u00a0\/ \u03c1\u00a0<\/span><sub><span>g<\/span><\/sub><span>\u00a0&#8211; 1))\u00a0<\/span>\u00a0<span>e, portanto:<\/span><\/strong><br \/>\n<a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-pressure-drop-equation2.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-14902 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-pressure-drop-equation2.png\" alt=\"queda de press\u00e3o bif\u00e1sica - equa\u00e7\u00e3o2\" width=\"369\" height=\"78\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-pressure-drop-equation2.png\" \/><\/a><\/p>\n<p><span>Como pode ser visto, este modelo simples sugere que as\u00a0<\/span><strong><span>perdas por atrito bif\u00e1sicas s\u00e3o, de qualquer forma, superiores \u00e0s perdas por atrito monof\u00e1sico.\u00a0<\/span><\/strong><span>O multiplicador de atrito homog\u00eaneo aumenta rapidamente com a\u00a0<\/span><a title=\"Qualidade est\u00e1tica - Qualidade do fluxo\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/two-phase-fluid-flow\/static-quality-flow-quality\/\"><strong><span>qualidade do fluxo<\/span><\/strong><\/a><span>\u00a0.<\/span><\/p>\n<p><span>As\u00a0<\/span><strong><span>qualidades<\/span><\/strong><span>\u00a0t\u00edpicas de\u00a0<strong>fluxo<\/strong>\u00a0em\u00a0<\/span><a title=\"Gerador de vapor\" href=\"https:\/\/www.nuclear-power.com\/steam-generator\/\"><strong><span>geradores de vapor<\/span><\/strong><\/a><span>\u00a0e\u00a0<\/span><a title=\"BWR - Reator de \u00e1gua fervente\" href=\"https:\/\/www.nuclear-power.com\/bwr-boiling-water-reactor\/\"><strong><span>n\u00facleos BWR<\/span><\/strong><\/a><span>\u00a0s\u00e3o da ordem de 10 a 20%.\u00a0A perda de fric\u00e7\u00e3o bif\u00e1sica correspondente seria ent\u00e3o\u00a0<\/span><strong><span>2 a 4<\/span><\/strong><span>\u00a0vezes a de um sistema monof\u00e1sico equivalente.<\/span><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\"><\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<h2><span>Instabilidade de fluxo<\/span><\/h2>\n<p><span>Em geral, existem\u00a0<\/span><strong><span>v\u00e1rias instabilidades<\/span><\/strong><span>\u00a0que podem ocorrer em\u00a0<\/span><strong><span>sistemas de duas fases<\/span><\/strong><span>\u00a0.\u00a0Na\u00a0<\/span><a title=\"Engenharia nuclear\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/\"><span>engenharia nuclear<\/span><\/a><span>\u00a0, o estudo da\u00a0<\/span><strong><span>estabilidade de fluxo multif\u00e1sico<\/span><\/strong><span>\u00a0\u00e9 importante no\u00a0<\/span><strong><span>gerenciamento<\/span><\/strong><span>\u00a0de\u00a0<strong>acidentes<\/strong>\u00a0de\u00a0<\/span><a title=\"PWR - Reator de \u00e1gua pressurizada\" href=\"https:\/\/www.nuclear-power.com\/pwr-pressurized-water-reactor\/\"><span>reatores de \u00e1gua pressurizada<\/span><\/a><span>\u00a0e da\u00a0<\/span><strong><span>maior import\u00e2ncia<\/span><\/strong><span>\u00a0em\u00a0<\/span><strong><span>condi\u00e7\u00f5es normais \/ anormais<\/span><\/strong><span>\u00a0em\u00a0<\/span><a title=\"BWR - Reator de \u00e1gua fervente\" href=\"https:\/\/www.nuclear-power.com\/bwr-boiling-water-reactor\/\"><span>reatores de \u00e1gua fervente<\/span><\/a><span>\u00a0.<\/span><\/p>\n<p><span>Em\u00a0<\/span><strong><span>PWRs<\/span><\/strong><span>\u00a0em\u00a0<\/span><strong><span>opera\u00e7\u00e3o normal,<\/span><\/strong><span>\u00a0o fluxo \u00e9 considerado monof\u00e1sico.\u00a0Por\u00e9m, muitos estudos foram realizados sobre a instabilidade do fluxo em caso de\u00a0<\/span><strong><span>transientes e acidentes<\/span><\/strong><span>\u00a0(como o\u00a0<strong>acidente<\/strong>\u00a0com\u00a0<\/span><strong><span>perda de refrigerante &#8211; LOCA ou o disparo de RCPs com presen\u00e7a de circula\u00e7\u00e3o natural<\/span><\/strong><span>\u00a0)\u00a0<\/span><strong><span>,<\/span><\/strong><span>\u00a0em que oscila\u00e7\u00f5es ou revers\u00f5es de fluxo podem ocorrer. ocorrer.<\/span><\/p>\n<p><span>As oscila\u00e7\u00f5es de fluxo s\u00e3o varia\u00e7\u00f5es no fluxo causadas especialmente por forma\u00e7\u00f5es vazias e s\u00e3o indesej\u00e1veis \u200b\u200bpor v\u00e1rias raz\u00f5es.<\/span><\/p>\n<ul>\n<li><span>As oscila\u00e7\u00f5es de fluxo podem causar\u00a0<\/span><strong><span>tens\u00f5es mec\u00e2nicas indesej\u00e1veis<\/span><\/strong><span>\u00a0nos componentes do combust\u00edvel (como grades espa\u00e7adoras).\u00a0Isso pode levar \u00e0 falha desses componentes devido \u00e0 fadiga.<\/span><\/li>\n<li><span>As oscila\u00e7\u00f5es de fluxo afetam as\u00a0caracter\u00edsticas\u00a0<\/span><strong><span>locais de transfer\u00eancia de calor<\/span><\/strong><span>\u00a0.\u00a0No caso de\u00a0<\/span><a title=\"PWR - Reator de \u00e1gua pressurizada\" href=\"https:\/\/www.nuclear-power.com\/pwr-pressurized-water-reactor\/\"><span>PWRs<\/span><\/a><span>\u00a0, a quest\u00e3o cr\u00edtica de seguran\u00e7a \u00e9 denominada\u00a0<\/span><strong><span>DNB<\/span><\/strong><span>\u00a0(\u00a0<\/span><strong><span>partida da ebuli\u00e7\u00e3o nucleada<\/span><\/strong><span>\u00a0), que causa a forma\u00e7\u00e3o de uma\u00a0<\/span><strong><span>camada de vapor local<\/span><\/strong><span>\u00a0, causando uma redu\u00e7\u00e3o dr\u00e1stica na capacidade de transfer\u00eancia de calor.\u00a0Verificou-se atrav\u00e9s de testes que o\u00a0<\/span><strong><span>fluxo de calor cr\u00edtico (CHF)<\/span><\/strong><span>\u00a0necess\u00e1rio para sair da ebuli\u00e7\u00e3o nucleada (DNB) pode ser reduzido em at\u00e9 40% quando o fluxo est\u00e1 oscilando.\u00a0Isso reduz severamente o\u00a0<\/span><strong><span>limite t\u00e9rmico<\/span><\/strong><span>\u00a0e a densidade de pot\u00eancia ao longo do comprimento do\u00a0<\/span><a title=\"N\u00facleo do reator\" href=\"https:\/\/www.reactor-physics.com\/what-is-reactor-core-definition\/\"><span>n\u00facleo<\/span><\/a><span>\u00a0do\u00a0<a title=\"N\u00facleo do reator\" href=\"https:\/\/www.reactor-physics.com\/what-is-reactor-core-definition\/\">reator<\/a>\u00a0.<\/span><\/li>\n<\/ul>\n<p><span>As oscila\u00e7\u00f5es de fluxo podem ser um problema durante\u00a0opera\u00e7\u00f5es de\u00a0<\/span><strong><span>circula\u00e7\u00e3o natural<\/span><\/strong><span>\u00a0(por exemplo, ap\u00f3s o disparo de todos os RCPs).\u00a0<\/span><strong><span>A circula\u00e7\u00e3o natural<\/span><\/strong><span>\u00a0\u00e9 uma caracter\u00edstica importante do projeto e o melhor mecanismo de remo\u00e7\u00e3o de calor.\u00a0Devido \u00e0s baixas taxas de vaz\u00e3o, pode ocorrer uma ebuli\u00e7\u00e3o do l\u00edquido refrigerante e isso pode formar oscila\u00e7\u00f5es de fluxo.\u00a0Durante a circula\u00e7\u00e3o natural, as bolhas de vapor formadas durante uma oscila\u00e7\u00e3o de fluxo podem ter efeito suficiente para realmente causar a revers\u00e3o completa do fluxo no canal afetado.<\/span><\/p>\n<figure id=\"attachment_14932\" class=\"wp-caption alignright\" aria-describedby=\"caption-attachment-14932\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/BWR-flow-instability.png\"><img loading=\"lazy\" class=\"size-medium wp-image-14932 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/BWR-flow-instability-300x177.png\" alt=\"BWR - instabilidade do fluxo\" width=\"300\" height=\"177\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/BWR-flow-instability-300x177.png\" \/><\/a><figcaption id=\"caption-attachment-14932\" class=\"wp-caption-text\"><span>Regi\u00e3o de instabilidade no mapa de fluxo de pot\u00eancia do reator BWR.\u00a0Fonte: Francesco D&#8217;Auria, The BWR Stability Issue, THICKET 2008 &#8211; Sess\u00e3o IX &#8211; Documento 26<\/span><\/figcaption><\/figure>\n<p><strong><span>Nos\u00a0<\/span><a title=\"BWR - Reator de \u00e1gua fervente\" href=\"https:\/\/www.nuclear-power.com\/bwr-boiling-water-reactor\/\"><span>BWRs, a<\/span><\/a><\/strong><span>\u00a0evapora\u00e7\u00e3o do l\u00edquido refrigerante ocorre em\u00a0<\/span><strong><span>opera\u00e7\u00e3o normal<\/span><\/strong><span>\u00a0e \u00e9 um fen\u00f4meno muito desejado.\u00a0Por outro lado, a evapora\u00e7\u00e3o convectiva no canal de combust\u00edvel faz com que o\u00a0<\/span><a title=\"Padr\u00f5es de fluxo - fluxo bif\u00e1sico\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/two-phase-fluid-flow\/flow-patterns-two-phase-flow\/\"><span>padr\u00e3o de fluxo seja<\/span><\/a><span>\u00a0alterado ao longo do canal de combust\u00edvel, dependendo da taxa de fluxo e da energia t\u00e9rmica.\u00a0Verificou-se que existem\u00a0<\/span><strong><span>regi\u00f5es de instabilidade<\/span><\/strong><span>\u00a0, nas quais podem surgir instabilidades de fluxo em duas fases.\u00a0Essas instabilidades de fluxo bif\u00e1sicas s\u00e3o indesej\u00e1veis, pois podem resultar em vibra\u00e7\u00f5es mec\u00e2nicas e problemas de controle do sistema, afetar a opera\u00e7\u00e3o normal, restringir os par\u00e2metros operacionais e influenciar a seguran\u00e7a do reator.\u00a0Deve-se notar que a estabilidade do fluxo nos BWRs n\u00e3o \u00e9 uma quest\u00e3o importante h\u00e1 muitos anos, porque \u00e9 um fen\u00f4meno bem conhecido.<\/span><\/p>\n<p><span>Em geral, existem muitas classifica\u00e7\u00f5es de instabilidades de fluxo.\u00a0A seguinte classifica\u00e7\u00e3o \u00e9 baseada em mecanismos fundamentais termo-hidr\u00e1ulicos:<\/span><\/p>\n<p><strong><span>As instabilidades est\u00e1ticas<\/span><\/strong><span>\u00a0s\u00e3o:<\/span><\/p>\n<ul>\n<li><strong><span>Excurs\u00e3o de fluxo<\/span><\/strong><\/li>\n<li><strong><span>Crise fervente<\/span><\/strong><\/li>\n<li><strong><span>Tipos de relaxamento, incluindo transi\u00e7\u00e3o do padr\u00e3o de fluxo<\/span><\/strong><\/li>\n<\/ul>\n<p><strong><span>As instabilidades din\u00e2micas<\/span><\/strong><span>\u00a0s\u00e3o:<\/span><\/p>\n<ul>\n<li><strong><span>Oscila\u00e7\u00f5es de ondas de densidade<\/span><\/strong><\/li>\n<li><strong><span>Oscila\u00e7\u00f5es de queda de press\u00e3o<\/span><\/strong><\/li>\n<li><strong><span>Oscila\u00e7\u00f5es t\u00e9rmicas<\/span><\/strong><span>\u00a0.<\/span><\/li>\n<\/ul>\n<p><span>A caracteriza\u00e7\u00e3o adequada das instabilidades e as condi\u00e7\u00f5es para sua ocorr\u00eancia podem determinar a opera\u00e7\u00e3o ideal e segura dos sistemas.\u00a0A explica\u00e7\u00e3o mais aceita para a ocorr\u00eancia do tipo din\u00e2mico de instabilidades denominadas\u00a0<\/span><strong><span>oscila\u00e7\u00f5es de ondas de densidade (DWO)<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><strong><span>A onda de densidade<\/span><\/strong><span>\u00a0causa um atraso na\u00a0<\/span><strong><span>queda de press\u00e3o local<\/span><\/strong><span>\u00a0causada por uma mudan\u00e7a no fluxo de entrada.\u00a0Devido a esse atraso, a soma de todas as quedas de press\u00e3o locais pode resultar em uma queda total que est\u00e1\u00a0<\/span><strong><span>fora de fase<\/span><\/strong><span>\u00a0com o fluxo de entrada.\u00a0O mecanismo b\u00e1sico que causa instabilidades de fluxo nos BWRs \u00e9 a onda de densidade.\u00a0Os per\u00edodos caracter\u00edsticos dessas oscila\u00e7\u00f5es est\u00e3o associados ao tempo necess\u00e1rio para uma part\u00edcula de fluido percorrer todo o loop.<\/span><\/p>\n<p><span>Tipos de instabilidades observadas nos BWRs<\/span><\/p>\n<ul>\n<li><strong><span>Instabilidades do sistema de controle.\u00a0<\/span><\/strong><span>As instabilidades do sistema de controle est\u00e3o relacionadas \u00e0 a\u00e7\u00e3o dos controladores que, atrav\u00e9s de atuadores, tentam regular algumas das vari\u00e1veis \u200b\u200bdo reator.<\/span><\/li>\n<li><strong><span>Instabilidades de fluxo de canal.\u00a0<\/span><\/strong><span>Este tipo de instabilidade pode ser descrito da seguinte forma: Vamos assumir uma perturba\u00e7\u00e3o do fluxo.\u00a0Essa perturba\u00e7\u00e3o causa uma &#8220;onda&#8221; de vazios viajando para cima atrav\u00e9s do canal, produzindo uma queda de press\u00e3o em duas fases (a queda de press\u00e3o aumenta significativamente \u00e0 medida que a fra\u00e7\u00e3o de vazios aumenta) que \u00e9 atrasada em rela\u00e7\u00e3o \u00e0 perturba\u00e7\u00e3o original.\u00a0Um aumento na queda de press\u00e3o do canal (onda de densidade) pode levar \u00e0 instabilidade na taxa de fluxo.<\/span><\/li>\n<li><strong><span>Instabilidade neutr\u00f4nica-termo-hidr\u00e1ulica acoplada.\u00a0<\/span><\/strong><span>O tipo dominante de instabilidades nos BWRs comerciais \u00e9 a instabilidade neutr\u00f4nica-termo-hidr\u00e1ulica acoplada (tamb\u00e9m conhecida como\u00a0<\/span><strong><span>instabilidade<\/span><\/strong><span>\u00a0da\u00a0<strong>reatividade<\/strong>\u00a0).\u00a0A gera\u00e7\u00e3o de energia em BWRs est\u00e1 diretamente relacionada ao\u00a0<\/span><a title=\"Densidade de fluxo de n\u00eautrons - Intensidade de n\u00eautrons\" href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/neutron-flux-neutron-intensity\/\"><strong><span>fluxo de n\u00eautrons de<\/span><\/strong><\/a><span>\u00a0combust\u00edvel\u00a0, que est\u00e1 fortemente relacionado \u00e0\u00a0<\/span><a title=\"Fra\u00e7\u00e3o de Vazio - Fluxo de Duas Fases\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/two-phase-fluid-flow\/void-fraction-two-phase-flow\/\"><strong><span>fra\u00e7\u00e3o<\/span><\/strong><\/a><span>\u00a0m\u00e9dia de\u00a0<a title=\"Void Fraction \u2013 Two-phase Flow\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/two-phase-fluid-flow\/void-fraction-two-phase-flow\/\"><strong>vazios<\/strong><\/a>\u00a0nos canais principais.\u00a0Esse efeito \u00e9 conhecido como\u00a0<\/span><a title=\"Coeficientes de reatividade - Feedbacks de reatividade\" href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/nuclear-fission-chain-reaction\/reactivity-coefficients-reactivity-feedbacks\/\"><strong><span>feedback de reatividade<\/span><\/strong><\/a><span>\u00a0.\u00a0O feedback de reatividade causado por altera\u00e7\u00f5es na fra\u00e7\u00e3o de vazio (\u00a0<\/span><a title=\"Coeficiente de Vazio\" href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/nuclear-fission-chain-reaction\/reactivity-coefficients-reactivity-feedbacks\/void-coefficient\/\"><span>coeficiente de vazio<\/span><\/a><span>\u00a0) \u00e9 atrasado \u00e0 medida que os vazios viajam para cima atrav\u00e9s do canal de combust\u00edvel.\u00a0Em alguns casos, o atraso pode ser longo o suficiente e o\u00a0<\/span><strong><span>feedback nulo<\/span><\/strong><span>pode ser forte o suficiente para que a configura\u00e7\u00e3o do reator se torne inst\u00e1vel.\u00a0Nesse caso, o fluxo de n\u00eautrons pode oscilar.<\/span><\/li>\n<\/ul>\n<p><span>Refer\u00eancias especiais:<\/span><\/p>\n<ul>\n<li><span>Francesco D&#8217;Auria, The BWR Stability Issue, THICKET 2008 &#8211; Sess\u00e3o IX &#8211; Documento 26<\/span><\/li>\n<li><span>Dag Str\u00f8msv\u00e5g, Mecanismos fundamentais das oscila\u00e7\u00f5es das ondas de densidade e o efeito do sub-resfriamento, NTNU, 2011.<\/span><\/li>\n<li><span>J. March-Leuba, Instabilidades de ondas de densidade em reatores de \u00e1gua fervente.\u00a0NUREG \/ CR-6003, ORNL, 1992.<\/span><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"su-divider su-divider-style-dotted\"><\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-accordion\"><\/div>\n<p>&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;.<\/p>\n<p>Este artigo \u00e9 baseado na tradu\u00e7\u00e3o autom\u00e1tica do artigo original em ingl\u00eas. Para mais informa\u00e7\u00f5es, consulte o artigo em ingl\u00eas. Voc\u00ea pode nos ajudar. Se voc\u00ea deseja corrigir a tradu\u00e7\u00e3o, envie-a para: translations@nuclear-power.com ou preencha o formul\u00e1rio de tradu\u00e7\u00e3o on-line. Agradecemos sua ajuda, atualizaremos a tradu\u00e7\u00e3o o mais r\u00e1pido poss\u00edvel. Obrigado.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Por defini\u00e7\u00e3o, o fluxo bif\u00e1sico \u00e9 o fluxo interativo de duas fases distintas com interfaces comuns em, por exemplo, um condu\u00edte.\u00a0Fluxo de fluido bif\u00e1sico &#8211; fluxo g\u00e1s-l\u00edquido.\u00a0Engenharia T\u00e9rmica Fluxo de fluido bif\u00e1sico Por defini\u00e7\u00e3o, o\u00a0fluxo multif\u00e1sico\u00a0\u00e9 o fluxo interativo de\u00a0duas ou mais\u00a0fases distintas com interfaces comuns em, por exemplo, um condu\u00edte.\u00a0Cada fase, representando uma fra\u00e7\u00e3o &#8230; <a title=\"O que \u00e9 fluxo de fluido bif\u00e1sico &#8211; defini\u00e7\u00e3o\" class=\"read-more\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-de-fluido-bifasico-definicao\/\" aria-label=\"More on O que \u00e9 fluxo de fluido bif\u00e1sico &#8211; defini\u00e7\u00e3o\">Ler mais<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[14],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v15.4 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>O que \u00e9 fluxo de fluido bif\u00e1sico - defini\u00e7\u00e3o<\/title>\n<meta name=\"description\" content=\"Por defini\u00e7\u00e3o, o fluxo bif\u00e1sico \u00e9 o fluxo interativo de duas fases distintas com interfaces comuns em, por exemplo, um condu\u00edte. Fluxo de fluido bif\u00e1sico - fluxo g\u00e1s-l\u00edquido. Engenharia T\u00e9rmica\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-de-fluido-bifasico-definicao\/\" \/>\n<meta property=\"og:locale\" content=\"pt_BR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"O que \u00e9 fluxo de fluido bif\u00e1sico - defini\u00e7\u00e3o\" \/>\n<meta property=\"og:description\" content=\"Por defini\u00e7\u00e3o, o fluxo bif\u00e1sico \u00e9 o fluxo interativo de duas fases distintas com interfaces comuns em, por exemplo, um condu\u00edte. Fluxo de fluido bif\u00e1sico - fluxo g\u00e1s-l\u00edquido. Engenharia T\u00e9rmica\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-de-fluido-bifasico-definicao\/\" \/>\n<meta property=\"og:site_name\" content=\"Thermal Engineering\" \/>\n<meta property=\"article:published_time\" content=\"2020-02-01T16:08:12+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2020-02-01T16:25:48+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-fluid-flow.png\" \/>\n<meta name=\"twitter:card\" content=\"summary\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\">\n\t<meta name=\"twitter:data1\" content=\"Nick Connor\">\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\">\n\t<meta name=\"twitter:data2\" content=\"14 minutos\">\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#website\",\"url\":\"https:\/\/www.thermal-engineering.org\/fr\/\",\"name\":\"Thermal Engineering\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":\"https:\/\/www.thermal-engineering.org\/fr\/?s={search_term_string}\",\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"pt-BR\"},{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-de-fluido-bifasico-definicao\/#primaryimage\",\"inLanguage\":\"pt-BR\",\"url\":\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/two-phase-fluid-flow.png\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-de-fluido-bifasico-definicao\/#webpage\",\"url\":\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-de-fluido-bifasico-definicao\/\",\"name\":\"O que \\u00e9 fluxo de fluido bif\\u00e1sico - defini\\u00e7\\u00e3o\",\"isPartOf\":{\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-de-fluido-bifasico-definicao\/#primaryimage\"},\"datePublished\":\"2020-02-01T16:08:12+00:00\",\"dateModified\":\"2020-02-01T16:25:48+00:00\",\"author\":{\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#\/schema\/person\/e8c544db9afedaec8574d6464f9398bb\"},\"description\":\"Por defini\\u00e7\\u00e3o, o fluxo bif\\u00e1sico \\u00e9 o fluxo interativo de duas fases distintas com interfaces comuns em, por exemplo, um condu\\u00edte. Fluxo de fluido bif\\u00e1sico - fluxo g\\u00e1s-l\\u00edquido. Engenharia T\\u00e9rmica\",\"inLanguage\":\"pt-BR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-de-fluido-bifasico-definicao\/\"]}]},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#\/schema\/person\/e8c544db9afedaec8574d6464f9398bb\",\"name\":\"Nick Connor\",\"image\":{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#personlogo\",\"inLanguage\":\"pt-BR\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/84c0dec310b44b65da29dc9df6925239?s=96&d=mm&r=g\",\"caption\":\"Nick Connor\"}}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","_links":{"self":[{"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/posts\/51897"}],"collection":[{"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/comments?post=51897"}],"version-history":[{"count":0,"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/posts\/51897\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/media?parent=51897"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/categories?post=51897"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/tags?post=51897"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}