{"id":51955,"date":"2020-02-01T20:17:31","date_gmt":"2020-02-01T19:17:31","guid":{"rendered":"https:\/\/www.thermal-engineering.org\/o-que-e-perda-de-carga-principal-perda-por-atrito-definicao\/"},"modified":"2020-02-01T20:20:10","modified_gmt":"2020-02-01T19:20:10","slug":"o-que-e-perda-de-carga-principal-perda-por-atrito-definicao","status":"publish","type":"post","link":"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-perda-de-carga-principal-perda-por-atrito-definicao\/","title":{"rendered":"O que \u00e9 perda de carga principal &#8211; perda por atrito &#8211; defini\u00e7\u00e3o"},"content":{"rendered":"<div class=\"su-quote su-quote-style-default\">\n<div class=\"su-quote-inner su-clearfix\">As principais perdas de carga, associadas \u00e0 perda de energia de atrito por comprimento de tubo, s\u00e3o importantes no projeto de sistemas hidr\u00e1ulicos. Perda de fric\u00e7\u00e3o no tubo. Engenharia T\u00e9rmica<\/div>\n<\/div>\n<div><\/div>\n<div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-60 lgc-tablet-grid-60 lgc-mobile-grid-100 lgc-equal-heights  lgc-first\">\n<div class=\"inside-grid-column\">\n<h2><span>Perda de Cabe\u00e7a Maior &#8211; Perda por Fric\u00e7\u00e3o<\/span><\/h2>\n<p><strong><span>As principais perdas<\/span><\/strong><span>\u00a0associadas \u00e0\u00a0<\/span><strong><span>perda de energia de atrito<\/span><\/strong><span>\u00a0por comprimento do tubo dependem da\u00a0<\/span><strong><span>velocidade<\/span><\/strong><span>\u00a0do\u00a0<strong>fluxo, comprimento do tubo, di\u00e2metro do tubo e um fator de atrito<\/strong>\u00a0baseado na rugosidade do tubo, e se o fluxo \u00e9\u00a0<\/span><a title=\"Fluxo Laminar - Fluxo Viscoso\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-laminar-fluxo-viscoso-definicao\/\"><span>laminar<\/span><\/a><span>\u00a0ou\u00a0<\/span><a title=\"Fluxo turbulento\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-turbulento-definicao\/\"><span>turbulento<\/span><\/a><span>\u00a0(ou seja,\u00a0<\/span><a title=\"N\u00famero de Reynolds\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/reynolds-number\/\"><span>Reynolds n\u00famero<\/span><\/a><span>\u00a0do fluxo).<\/span><\/p>\n<p><span>Embora a\u00a0<strong>perda de carga\u00a0<\/strong><\/span><strong><span>represente uma perda de energia<\/span><\/strong><span>\u00a0, ela\u00a0<\/span><strong><span>n\u00e3o representa uma perda de energia total<\/span><\/strong><span>\u00a0do fluido.\u00a0A energia total do fluido conserva como conseq\u00fc\u00eancia da\u00a0<\/span><strong><span>lei de conserva\u00e7\u00e3o de energia<\/span><\/strong><span>\u00a0.\u00a0Na realidade, a perda de carga devido ao atrito resulta em um\u00a0<\/span><strong><span>aumento<\/span><\/strong><span>\u00a0equivalente\u00a0<strong>na energia interna<\/strong>\u00a0(aumento da temperatura) do fluido.<\/span><\/p>\n<p><span>Pela observa\u00e7\u00e3o, a\u00a0<\/span><strong><span>maior perda de carga \u00e9 aproximadamente proporcional ao quadrado da vaz\u00e3o<\/span><\/strong><span>\u00a0na maioria dos fluxos de engenharia (vaz\u00e3o de tubula\u00e7\u00e3o turbulenta e totalmente desenvolvida).<\/span><\/p>\n<p><span>A equa\u00e7\u00e3o mais comum usada para calcular as principais perdas de carga em um tubo ou duto \u00e9 a\u00a0<\/span><strong><span>equa\u00e7\u00e3o de Darcy-Weisbach<\/span><\/strong><span>\u00a0\u00a0.<\/span><\/p>\n<div class=\"su-divider su-divider-style-dotted\"><\/div>\n<div class=\"su-spacer\"><\/div>\n<h2><span>Equa\u00e7\u00e3o de Darcy-Weisbach<\/span><\/h2>\n<p><span>Na din\u00e2mica de fluidos,\u00a0<\/span><strong><span>a equa\u00e7\u00e3o de Darcy-Weisbach<\/span><\/strong><span>\u00a0\u00e9 uma equa\u00e7\u00e3o fenomenol\u00f3gica, que relaciona a\u00a0<\/span><strong><span>principal perda de<\/span><\/strong><span>\u00a0carga ou perda de press\u00e3o devido ao\u00a0<\/span><strong><span>atrito do fluido<\/span><\/strong><span>\u00a0ao longo de um determinado comprimento do tubo \u00e0 velocidade m\u00e9dia.\u00a0Esta equa\u00e7\u00e3o \u00e9 v\u00e1lida para\u00a0<\/span><strong><span>fluxo monof\u00e1sico totalmente desenvolvido, est\u00e1vel e incompress\u00edvel<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><span>A equa\u00e7\u00e3o de Darcy-Weisbach pode ser escrita em duas formas (\u00a0<\/span><strong><span>forma perda de press\u00e3o<\/span><\/strong><span>\u00a0ou\u00a0<\/span><strong><span>de formul\u00e1rio perda de carga<\/span><\/strong><span>\u00a0).\u00a0No formul\u00e1rio de perda de cabe\u00e7a pode ser escrito como:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Major-Head-Loss-head-form.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-14583 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Major-Head-Loss-head-form.png\" alt=\"Perda de Cabe\u00e7a Maior - forma da cabe\u00e7a\" width=\"199\" height=\"88\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Major-Head-Loss-head-form.png\" \/><\/a><\/p>\n<p><span>Onde:<\/span><\/p>\n<ul>\n<li><span>\u0394h = perda de carga devida ao atrito (m)<\/span><\/li>\n<li><em><span>f\u00a0<\/span><\/em><em><sub><span>D<\/span><\/sub><\/em><span>\u00a0= fator de atrito de Darcy (sem unidade)<\/span><\/li>\n<li><span>L = comprimento do tubo (m)<\/span><\/li>\n<li><span>D =\u00a0<\/span><a title=\"Di\u00e2metro hidr\u00e1ulico\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/internal-flow\/hydraulic-diameter-2\/\"><span>di\u00e2metro hidr\u00e1ulico<\/span><\/a><span>\u00a0do tubo D (m)<\/span><\/li>\n<li><span>g = constante gravitacional (m \/ s\u00a0<\/span><sup><span>2<\/span><\/sup><span>\u00a0)<\/span><\/li>\n<li><span>V = velocidade m\u00e9dia do fluxo V (m \/ s)<\/span><\/li>\n<\/ul>\n<div class=\"su-accordion\">\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\"><\/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 class=\"su-divider su-divider-style-dotted\"><\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-40 lgc-tablet-grid-40 lgc-mobile-grid-100 lgc-equal-heights  lgc-last\">\n<div class=\"inside-grid-column\">\n<h2><span>Resumo:<\/span><\/h2>\n<ul>\n<li><span>A perda de carga do sistema hidr\u00e1ulico \u00e9 dividida em\u00a0<\/span><strong><span>duas categorias principais<\/span><\/strong><span>\u00a0:<\/span>\n<ul>\n<li><strong><span>Perda de Cabe\u00e7a Maior<\/span><\/strong><span>\u00a0&#8211; devido ao atrito em tubos retos<\/span><\/li>\n<li><strong><span>Menor perda de carga<\/span><\/strong><span>\u00a0&#8211; devido a componentes como v\u00e1lvulas, curvas\u2026<\/span><\/li>\n<\/ul>\n<\/li>\n<li><strong><span>A equa\u00e7\u00e3o de Darcy<\/span><\/strong><span>\u00a0pode ser usada para calcular\u00a0<\/span><strong><span>grandes perdas<\/span><\/strong><span>\u00a0.<\/span><\/li>\n<li><span>O\u00a0<\/span><strong><span>fator de atrito<\/span><\/strong><span>\u00a0para o fluxo de fluido pode ser determinado usando um\u00a0<\/span><strong><span>gr\u00e1fico Moody<\/span><\/strong><span>\u00a0.<\/span><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Moody-chart-min.jpg\"><img loading=\"lazy\" class=\"aligncenter size-medium wp-image-14429 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Moody-chart-min-300x188.jpg\" alt=\"Moody chart-min\" width=\"300\" height=\"188\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Moody-chart-min-300x188.jpg\" \/><\/a><\/li>\n<li><strong><span>O fator de atrito<\/span><\/strong><span>\u00a0\u00a0para o fluxo laminar \u00e9\u00a0<\/span><strong><span>independente da rugosidade<\/span><\/strong><span>\u00a0da superf\u00edcie interna do tubo.\u00a0<\/span><strong><span>f = 64 \/ Re<\/span><\/strong><\/li>\n<li><strong><span>O fator de atrito<\/span><\/strong><span>\u00a0\u00a0para escoamento turbulento depende fortemente da\u00a0<\/span><strong><span>rugosidade relativa.\u00a0<\/span><\/strong><span>\u00c9 determinado pela equa\u00e7\u00e3o de Colebrook.\u00a0Deve-se notar que,\u00a0<\/span><strong><span>em n\u00fameros muito grandes de Reynolds<\/span><\/strong><span>\u00a0, o fator de atrito \u00e9 independente do n\u00famero de Reynolds.<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2><span>Por que a perda de cabe\u00e7a \u00e9 muito importante?<\/span><\/h2>\n<p><span>Como pode ser visto na figura, a perda de carga \u00e9 a\u00a0<\/span><strong><span>principal caracter\u00edstica<\/span><\/strong><span>\u00a0de qualquer sistema hidr\u00e1ulico.\u00a0Nos sistemas em que uma certa vaz\u00e3o deve ser mantida (por exemplo, para fornecer refrigera\u00e7\u00e3o ou transfer\u00eancia de calor suficiente a partir do\u00a0<\/span><a title=\"N\u00facleo do reator\" href=\"https:\/\/www.reactor-physics.com\/what-is-reactor-core-definition\/\"><span>n\u00facleo do reator<\/span><\/a><span>\u00a0),\u00a0<\/span><strong><span>o equil\u00edbrio<\/span><\/strong><span>\u00a0da\u00a0<\/span><strong><span>perda de carga<\/span><\/strong><span>\u00a0e da\u00a0\u00a0<\/span><strong><span>carga adicionada<\/span><\/strong><span>\u00a0por uma bomba determina a vaz\u00e3o atrav\u00e9s do sistema.<\/span><\/p>\n<figure id=\"attachment_14299\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-14299\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Hydraulic-Head-Q-H.png\"><img loading=\"lazy\" class=\"size-medium wp-image-14299 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Hydraulic-Head-Q-H-300x207.png\" alt=\"Diagrama caracter\u00edstico de QH da bomba centr\u00edfuga e do gasoduto\" width=\"300\" height=\"207\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Hydraulic-Head-Q-H-300x207.png\" \/><\/a><figcaption id=\"caption-attachment-14299\" class=\"wp-caption-text\"><span>Diagrama caracter\u00edstico de QH da bomba centr\u00edfuga e do gasoduto<\/span><\/figcaption><\/figure>\n<figure id=\"attachment_14305\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-14305\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Hydraulic-Head-Hydraulic-Grade-Line-min.png\"><img loading=\"lazy\" class=\"size-medium wp-image-14305 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Hydraulic-Head-Hydraulic-Grade-Line-min-300x230.png\" alt=\"Cabe\u00e7a Hidr\u00e1ulica - Linha Hidr\u00e1ulica\" width=\"300\" height=\"230\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Hydraulic-Head-Hydraulic-Grade-Line-min-300x230.png\" \/><\/a><figcaption id=\"caption-attachment-14305\" class=\"wp-caption-text\"><span>Linha de classifica\u00e7\u00e3o hidr\u00e1ulica e linhas de cabe\u00e7ote total para um tubo de di\u00e2metro constante com atrito.\u00a0Em uma tubula\u00e7\u00e3o real, h\u00e1 perdas de energia devido ao atrito &#8211; elas devem ser levadas em considera\u00e7\u00e3o, pois podem ser muito significativas.<\/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-divider su-divider-style-dotted\"><\/div>\n<p><span>A avalia\u00e7\u00e3o da\u00a0<\/span><strong><span>equa\u00e7\u00e3o de Darcy-Weisbach<\/span><\/strong><span>\u00a0fornece informa\u00e7\u00f5es sobre os fatores que afetam a perda de carga em um oleoduto.<\/span><\/p>\n<ul>\n<li><span>Considere que o\u00a0<\/span><strong><span>comprimento do tubo<\/span><\/strong><span>\u00a0ou canal \u00e9\u00a0<\/span><strong><span>dobrado<\/span><\/strong><span>\u00a0, a\u00a0<\/span><strong><span>perda de carga de atrito<\/span><\/strong><span>\u00a0resultante\u00a0<strong>dobrar\u00e1<\/strong>\u00a0.<\/span><\/li>\n<li><span>Em vaz\u00e3o constante e comprimento do tubo, a\u00a0<\/span><strong><span>perda de carga \u00e9 inversamente proporcional \u00e0 quarta pot\u00eancia de di\u00e2metro<\/span><\/strong><span>\u00a0(para fluxo laminar) e, assim, reduzir o di\u00e2metro do tubo pela metade aumenta a perda de carga em um fator de 16. Isso \u00e9 um aumento muito significativo na perda de carga e mostra por que tubos de di\u00e2metro maior levam a requisitos de energia de bombeamento muito menores.<\/span><\/li>\n<li><span>Como a perda de carga \u00e9 aproximadamente proporcional ao quadrado da vaz\u00e3o, ent\u00e3o se a\u00a0<\/span><strong><span>vaz\u00e3o for duplicada<\/span><\/strong><span>\u00a0, a\u00a0<\/span><strong><span>perda de carga aumentar\u00e1 em um fator de quatro<\/span><\/strong><span>\u00a0.<\/span><\/li>\n<li><span>A\u00a0<\/span><strong><span>perda de carga \u00e9 reduzida pela metade<\/span><\/strong><span>\u00a0(para fluxo laminar) quando a\u00a0<\/span><strong><span>viscosidade do fluido \u00e9 reduzida pela metade<\/span><\/strong><span>\u00a0.<\/span><\/li>\n<\/ul>\n<figure id=\"attachment_14429\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-14429\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Moody-chart-min.jpg\"><img loading=\"lazy\" class=\"size-large wp-image-14429 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Moody-chart-min-1024x642.jpg\" alt=\"Fonte: Donebythesecondlaw no idioma ingl\u00eas Wikipedia, CC BY-SA 3.0, https:\/\/commons.wikimedia.org\/w\/index.php?curid=4681366\" width=\"669\" height=\"419\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Moody-chart-min-1024x642.jpg\" \/><\/a><figcaption id=\"caption-attachment-14429\" class=\"wp-caption-text\"><span>Fonte: Donebythesecondlaw no idioma ingl\u00eas Wikipedia, CC BY-SA 3.0,<\/span><br \/>\n<span>https:\/\/commons.wikimedia.org\/w\/index.php?curid=4681366<\/span><\/figcaption><\/figure>\n<p><span>Com exce\u00e7\u00e3o do\u00a0<\/span><strong><span>fator de atrito de Darcy<\/span><\/strong><span>\u00a0, cada um desses termos (velocidade do fluxo,\u00a0<\/span><a title=\"Di\u00e2metro hidr\u00e1ulico\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/internal-flow\/hydraulic-diameter-2\/\"><span>di\u00e2metro hidr\u00e1ulico<\/span><\/a><span>\u00a0, comprimento de um tubo) pode ser facilmente medido.\u00a0O fator de atrito de Darcy leva em considera\u00e7\u00e3o as propriedades de densidade e viscosidade do fluido, al\u00e9m da\u00a0<\/span><strong><span>rugosidade<\/span><\/strong><span>\u00a0do\u00a0<strong>tubo<\/strong>\u00a0.\u00a0Esse fator pode ser avaliado pelo uso de v\u00e1rias rela\u00e7\u00f5es emp\u00edricas ou pode ser lido em gr\u00e1ficos publicados (por exemplo,\u00a0<\/span><strong><span>gr\u00e1fico Moody<\/span><\/strong><span> ).<\/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>Fator de atrito de Darcy<\/span><\/h2>\n<p><span>Existem dois fatores de atrito comuns em uso,\u00a0<\/span><strong><span>os fatores de atrito Darcy e Fanning<\/span><\/strong><span> .<\/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<div class=\"su-spoiler-content su-clearfix\"><\/div>\n<\/div>\n<\/div>\n<p><strong><span>O fator de atrito de Darcy<\/span><\/strong><span>\u00a0\u00e9 uma quantidade adimensional usada na equa\u00e7\u00e3o de Darcy-Weisbach, para a descri\u00e7\u00e3o de perdas por atrito em tubula\u00e7\u00e3o ou duto, bem como para fluxo em canal aberto.\u00a0Isso tamb\u00e9m \u00e9 chamado de\u00a0<\/span><strong><span>fator de atrito de Darcy-Weisbach<\/span><\/strong><span>\u00a0,\u00a0<\/span><strong><span>coeficiente de resist\u00eancia<\/span><\/strong><span>\u00a0ou simplesmente\u00a0<\/span><strong><span>fator de atrito<\/span><\/strong><span>\u00a0.<\/span><span>Determinou-se que o fator de atrito depende do\u00a0<\/span><a title=\"N\u00famero de Reynolds\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/reynolds-number\/\"><strong><span>n\u00famero de Reynolds<\/span><\/strong><\/a><span>\u00a0para o fluxo e do grau de rugosidade da superf\u00edcie interna do tubo (especialmente para\u00a0<\/span><a title=\"Fluxo turbulento\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-turbulento-definicao\/\"><span>fluxo turbulento<\/span><\/a><span>\u00a0).\u00a0O fator de atrito do fluxo laminar \u00e9 independente da rugosidade da superf\u00edcie interna do tubo.<\/span><br \/>\n<a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/darcy-friction-factor.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-14581 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/darcy-friction-factor.png\" alt=\"fator de atrito darcy\" width=\"354\" height=\"66\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/darcy-friction-factor.png\" \/><\/a><br \/>\n<span>A se\u00e7\u00e3o transversal do tubo tamb\u00e9m \u00e9 importante, pois os desvios da se\u00e7\u00e3o circular causar\u00e3o fluxos secund\u00e1rios que aumentam a perda de carga.\u00a0Tubos e dutos n\u00e3o circulares s\u00e3o geralmente tratados usando\u00a0<\/span><strong><span>o di\u00e2metro hidr\u00e1ulico<\/span><\/strong><span>\u00a0.<\/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>Rugosidade relativa<\/span><\/h2>\n<p><span>A quantidade usada para medir a\u00a0<\/span><strong><span>rugosidade da superf\u00edcie interna do tubo<\/span><\/strong><span>\u00a0\u00e9 chamada de\u00a0<\/span><strong><span>rugosidade relativa<\/span><\/strong><span>\u00a0e \u00e9 igual \u00e0 altura m\u00e9dia das irregularidades da superf\u00edcie (\u03b5) dividida pelo di\u00e2metro do tubo (D).<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/relative-roughness-equation.png\"><img loading=\"lazy\" class=\"wp-image-14577 aligncenter lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/relative-roughness-equation.png\" alt=\"rugosidade relativa - equa\u00e7\u00e3o\" width=\"243\" height=\"64\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/relative-roughness-equation.png\" \/><\/a><\/p>\n<p><span>, onde as irregularidades m\u00e9dias da superf\u00edcie da altura e o di\u00e2metro do tubo est\u00e3o em mil\u00edmetros.<\/span><\/p>\n<p><span>Se conhecermos a rugosidade relativa da superf\u00edcie interna do tubo, podemos obter o valor do\u00a0<\/span><strong><span>fator de atrito<\/span><\/strong><span>\u00a0no\u00a0<\/span><strong><span>Gr\u00e1fico Moody<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><span>O gr\u00e1fico Moody (tamb\u00e9m conhecido como diagrama Moody) \u00e9 um gr\u00e1fico em forma n\u00e3o dimensional que relaciona\u00a0<\/span><strong><span>o fator de atrito de Darcy<\/span><\/strong><span>\u00a0, o\u00a0<\/span><strong><span>n\u00famero de Reynolds<\/span><\/strong><span>\u00a0e a\u00a0<\/span><strong><span>rugosidade relativa do<\/span><\/strong><span>\u00a0fluxo totalmente desenvolvido em um tubo circular.<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/relative-roughness-absolute-roughness-friction-min.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-14587 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/relative-roughness-absolute-roughness-friction-min.png\" alt=\"rugosidade relativa - rugosidade absoluta\" width=\"390\" height=\"691\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/relative-roughness-absolute-roughness-friction-min.png\" \/><\/a><\/p>\n<p>&nbsp;<\/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<h2><span>Fator de atrito de Darcy para v\u00e1rios regimes de fluxo<\/span><\/h2>\n<p><span>A classifica\u00e7\u00e3o mais comum dos\u00a0<\/span><a title=\"Regime de fluxo\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/flow-regime\/\"><span>regimes<\/span><\/a><span>\u00a0de\u00a0<a title=\"Regime de fluxo\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/flow-regime\/\">fluxo<\/a>\u00a0\u00e9 de acordo com o n\u00famero de Reynolds.\u00a0<\/span><strong><span>O n\u00famero de Reynolds<\/span><\/strong><span>\u00a0\u00e9 um n\u00famero adimensional composto pelas caracter\u00edsticas f\u00edsicas do fluxo e determina se o fluxo \u00e9\u00a0<\/span><strong><span>laminar ou turbulento<\/span><\/strong><span>\u00a0.\u00a0Um n\u00famero crescente de Reynolds indica uma crescente turbul\u00eancia do fluxo.\u00a0Como pode ser visto no gr\u00e1fico Moody, tamb\u00e9m o fator de atrito de Darcy \u00e9 altamente dependente do regime de fluxo (ou seja, do n\u00famero de Reynolds).<\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n<div><\/div>\n<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","protected":false},"excerpt":{"rendered":"<p>As principais perdas de carga, associadas \u00e0 perda de energia de atrito por comprimento de tubo, s\u00e3o importantes no projeto de sistemas hidr\u00e1ulicos. Perda de fric\u00e7\u00e3o no tubo. Engenharia T\u00e9rmica Perda de Cabe\u00e7a Maior &#8211; Perda por Fric\u00e7\u00e3o As principais perdas\u00a0associadas \u00e0\u00a0perda de energia de atrito\u00a0por comprimento do tubo dependem da\u00a0velocidade\u00a0do\u00a0fluxo, comprimento do tubo, di\u00e2metro &#8230; <a title=\"O que \u00e9 perda de carga principal &#8211; perda por atrito &#8211; defini\u00e7\u00e3o\" class=\"read-more\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-perda-de-carga-principal-perda-por-atrito-definicao\/\" aria-label=\"More on O que \u00e9 perda de carga principal &#8211; perda por atrito &#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 perda de carga principal - perda por atrito - defini\u00e7\u00e3o<\/title>\n<meta name=\"description\" content=\"As principais perdas de carga, associadas \u00e0 perda de energia de atrito por comprimento de tubo, s\u00e3o importantes no projeto de sistemas hidr\u00e1ulicos. 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