{"id":51398,"date":"2020-01-26T17:55:51","date_gmt":"2020-01-26T16:55:51","guid":{"rendered":"https:\/\/www.thermal-engineering.org\/o-que-e-o-ciclo-de-atkinson-atkinson-engine-definicao\/"},"modified":"2020-01-26T17:57:33","modified_gmt":"2020-01-26T16:57:33","slug":"o-que-e-o-ciclo-de-atkinson-atkinson-engine-definicao","status":"publish","type":"post","link":"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-atkinson-atkinson-engine-definicao\/","title":{"rendered":"O que \u00e9 o Ciclo de Atkinson &#8211; Atkinson Engine &#8211; Defini\u00e7\u00e3o"},"content":{"rendered":"<div class=\"su-quote su-quote-style-default\">\n<div class=\"su-quote-inner su-clearfix\">Ciclo de Atkinson &#8211; motor de Atkinson.\u00a0O ciclo de Atkinson \u00e9 um ciclo termodin\u00e2mico projetado para fornecer maior efici\u00eancia \u00e0s custas da densidade de pot\u00eancia.\u00a0Engenharia T\u00e9rmica<\/div>\n<\/div>\n<div class=\"su-divider su-divider-style-dotted\"><\/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>Ciclo de Atkinson &#8211; Atkinson Engine<\/h2>\n<p>Em 1882, um engenheiro brit\u00e2nico,\u00a0<strong>James\u00a0<\/strong><strong>Atkinson,<\/strong>\u00a0avan\u00e7ou no estudo de motores t\u00e9rmicos, inventando v\u00e1rios\u00a0<a title=\"Motores t\u00e9rmicos\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-heat-engine-definicao\/\"><strong>motores t\u00e9rmicos<\/strong><\/a>\u00a0que tiveram uma efici\u00eancia aumentada ao longo do\u00a0<strong><a title=\"Ciclo Otto - Otto Engine\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-otto-otto-engine-definicao\/\">ciclo Otto<\/a><\/strong>\u00a0.\u00a0Isso foi alcan\u00e7ado com o uso de cursos de motor vari\u00e1veis \u200b\u200bde um eixo de manivela complexo.\u00a0O ciclo de Atkinson foi projetado para fornecer\u00a0<strong>maior efici\u00eancia<\/strong>\u00a0\u00e0s custas da densidade de pot\u00eancia.\u00a0Para dois motores de igual volume de cilindrada, aquele com ciclo Otto produziria o maior trabalho l\u00edquido e, se os motores funcionassem na mesma velocidade, maior pot\u00eancia.\u00a0Por outro lado, o ciclo de Atkinson teria maior efici\u00eancia t\u00e9rmica e, portanto, menor consumo de combust\u00edvel.<\/p>\n<p>A primeira implementa\u00e7\u00e3o do ciclo de Atkinson foi em 1882. Esse mecanismo \u00e9 conhecido como o &#8221;\u00a0<strong>Diferencial de 1882<\/strong>\u00a0&#8220;.\u00a0Foi organizado como um motor de pist\u00e3o oposto, o motor diferencial de Atkinson.\u00a0O pr\u00f3ximo mecanismo projetado por Atkinson em 1887 foi nomeado &#8221;\u00a0<strong>Motor de Ciclo<\/strong>\u00a0&#8221; (veja a figura)<\/p>\n<p>Recentemente, \u00e9 um dos\u00a0<strong>ciclos termodin\u00e2micos<\/strong>\u00a0que podem ser encontrados em\u00a0motores de\u00a0<a href=\"https:\/\/www.ekologicka-likvidace-vozidla.cz\/\">autom\u00f3veis<\/a>\u00a0e descreve o funcionamento de um motor de\u00a0<a href=\"https:\/\/www.likvidace-vozidla-praha.cz\/\">pist\u00e3o de<\/a>\u00a0igni\u00e7\u00e3o por\u00a0<a href=\"https:\/\/www.likvidace-vozidla-praha.cz\/\">fa\u00edsca<\/a>\u00a0.\u00a0O termo\u00a0<strong>ciclo de Atkinson<\/strong>\u00a0foi usado para descrever um\u00a0<strong>motor de ciclo Otto modificado<\/strong>\u00a0no qual a\u00a0<strong>v\u00e1lvula de admiss\u00e3o \u00e9 mantida aberta por mais tempo do<\/strong>\u00a0que o normal para permitir um fluxo reverso de ar de admiss\u00e3o no coletor de admiss\u00e3o.\u00a0Isso\u00a0<strong>reduz a\u00a0<a title=\"Taxa de compress\u00e3o - Ciclo Otto\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/thermodynamic-cycles\/otto-cycle-otto-engine\/compression-ratio-otto-cycle\/\">taxa de compacta\u00e7\u00e3o<\/a><\/strong>\u00a0, mas a taxa de expans\u00e3o permanece a mesma.\u00a0Do ponto de vista mec\u00e2nico, o motor Atkinson \u00e9 semelhante ao motor Otto.\u00a0A principal diferen\u00e7a est\u00e1 na \u00e1rvore de cames ou nas \u00e1rvores de cames.<\/p>\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<div class=\"su-youtube su-responsive-media-yes\"><iframe class=\"lazy-loaded\" src=\"https:\/\/www.youtube.com\/embed\/X_jZbYL6xi4?\" width=\"340\" height=\"200\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\" data-lazy-type=\"iframe\" data-src=\"https:\/\/www.youtube.com\/embed\/X_jZbYL6xi4?\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<figure id=\"attachment_17624\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-17624\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-Engine.png\"><img loading=\"lazy\" class=\"size-medium wp-image-17624 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-Engine-300x173.png\" alt=\"Motor a g\u00e1s Atkinson\" width=\"300\" height=\"173\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-Engine-300x173.png\" \/><\/a><figcaption id=\"caption-attachment-17624\" class=\"wp-caption-text\">Motor a g\u00e1s Atkinson, como mostrado na Patente US 367496<\/figcaption><\/figure>\n<figure id=\"attachment_17623\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-17623\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-cycle-pV-diagram.png\"><img loading=\"lazy\" class=\"size-medium wp-image-17623 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-cycle-pV-diagram-300x240.png\" alt=\"Ciclo de Atkinson - diagrama pV\" width=\"300\" height=\"240\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-cycle-pV-diagram-300x240.png\" \/><\/a><figcaption id=\"caption-attachment-17623\" class=\"wp-caption-text\">Ciclo de Atkinson &#8211; diagrama pV<\/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>Ciclo de Atkinson &#8211; Processos<\/h2>\n<p>Em um\u00a0<strong>ciclo de Atkinson<\/strong>\u00a0(\u00a0<strong>ciclo<\/strong>\u00a0Otto modificado), o sistema que executa o ciclo passa por uma s\u00e9rie de quatro processos: dois processos isentr\u00f3picos (adiab\u00e1ticos revers\u00edveis) alternados com um processo isoc\u00f3rico e um processo isob\u00e1rico:<\/p>\n<ul>\n<li><a title=\"Processo isentr\u00f3pico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-processo-isentropico-definicao\/\"><strong>Compress\u00e3o isentr\u00f3pica<\/strong><\/a>\u00a0(curso de compress\u00e3o) &#8211; O g\u00e1s (mistura combust\u00edvel-ar) \u00e9 comprimido adiabaticamente do estado 1 ao estado 2, \u00e0 medida que o pist\u00e3o se move do ponto de fechamento da v\u00e1lvula de admiss\u00e3o (1) para o ponto morto superior.\u00a0O ambiente trabalha com o g\u00e1s, aumentando sua energia interna (temperatura) e comprimindo-o.\u00a0Por outro lado, a entropia permanece inalterada.\u00a0As mudan\u00e7as nos volumes e sua propor\u00e7\u00e3o (<em>\u00a0V\u00a0<\/em><em><sub>1<\/sub><\/em><em>\u00a0\/ V\u00a0<\/em><em><sub>2<\/sub><\/em>\u00a0) s\u00e3o conhecidas como<a title=\"Taxa de compress\u00e3o - Ciclo Otto\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/thermodynamic-cycles\/otto-cycle-otto-engine\/compression-ratio-otto-cycle\/\">\u00a0taxa de compress\u00e3o<\/a>\u00a0.\u00a0A taxa de compacta\u00e7\u00e3o \u00e9 menor que a taxa de expans\u00e3o.<\/li>\n<li><a title=\"Processo Isoc\u00f3rico - Processo Isom\u00e9trico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-processo-isocorico-processo-isometrico-definicao\/\"><strong>Compress\u00e3o isoc\u00f3rica<\/strong><\/a>\u00a0(fase de igni\u00e7\u00e3o) &#8211; Nesta fase (entre o estado 2 e o estado 3), h\u00e1 um volume constante (o pist\u00e3o est\u00e1 em repouso) transferido para o ar a partir de uma fonte externa, enquanto o pist\u00e3o est\u00e1 em repouso no ponto morto superior .\u00a0Este processo \u00e9 semelhante ao processo isoc\u00f3rico no ciclo Otto.\u00a0Pretende-se representar a igni\u00e7\u00e3o da mistura combust\u00edvel-ar injetada na c\u00e2mara e a subsequente queima r\u00e1pida.\u00a0A press\u00e3o aumenta e a raz\u00e3o (<em>\u00a0P\u00a0<\/em><em><sub>3<\/sub><\/em><em>\u00a0\/ P\u00a0<\/em><em><sub>2<\/sub><\/em> ) \u00e9 conhecida como \u201ctaxa de explos\u00e3o\u201d.<\/li>\n<\/ul>\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<ul>\n<li><a title=\"Processo isentr\u00f3pico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-processo-isentropico-definicao\/\"><strong><span>Expans\u00e3o isentr\u00f3pica<\/span><\/strong><\/a><span>\u00a0(golpe de energia) &#8211; O g\u00e1s se expande adiabaticamente do estado 3 para o estado 4, conforme o pist\u00e3o se move do ponto morto superior para o ponto morto inferior.\u00a0O g\u00e1s trabalha nos arredores (pist\u00e3o) e perde uma quantidade de energia interna igual ao trabalho que sai do sistema.\u00a0Novamente a entropia permanece inalterada.\u00a0A taxa de volume (<\/span><em><span>\u00a0V\u00a0<\/span><\/em><em><sub><span>4<\/span><\/sub><\/em><em><span>\u00a0\/ V\u00a0<\/span><\/em><em><sub><span>3<\/span><\/sub><\/em><span>\u00a0) \u00e9 conhecida como taxa de expans\u00e3o isentr\u00f3pica.<\/span><\/li>\n<li><strong><a title=\"Processo isob\u00e1rico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-processo-isobarico-definicao\/\"><span>Exaust\u00e3o isob\u00e1rica<\/span><\/a><span>\u00a0(curso de exaust\u00e3o)<\/span><\/strong><span>\u00a0&#8211; O objetivo principal do ciclo moderno de Atkinson \u00e9 permitir que a press\u00e3o na c\u00e2mara de combust\u00e3o no final do curso de pot\u00eancia seja igual \u00e0 press\u00e3o atmosf\u00e9rica.\u00a0Como pode haver press\u00e3o atmosf\u00e9rica na c\u00e2mara, n\u00e3o h\u00e1 descompress\u00e3o como no ciclo Otto.\u00a0O pist\u00e3o se move do ponto morto inferior (BDC) para o ponto morto superior (TDC) e o ciclo passa pelos pontos<\/span><strong><span>\u00a04 \u2192 1 \u2192 0.<\/span><\/strong><span>\u00a0Nesse curso, a v\u00e1lvula de escape est\u00e1 aberta enquanto o pist\u00e3o puxa os gases de escape para fora da c\u00e2mara.<\/span><\/li>\n<\/ul>\n<p><span>Durante o\u00a0<\/span><strong><span>ciclo de Atkinson<\/span><\/strong><span>\u00a0, o trabalho \u00e9 realizado no g\u00e1s pelo pist\u00e3o entre os estados 1 e 2 (\u00a0<\/span><strong><span>compress\u00e3o isentr\u00f3pica<\/span><\/strong><span>\u00a0).\u00a0O trabalho \u00e9 realizado pelo g\u00e1s no pist\u00e3o entre os est\u00e1gios 3 e 4 (\u00a0<\/span><strong><span>expans\u00e3o isentr\u00f3pica<\/span><\/strong><span>\u00a0).\u00a0A diferen\u00e7a entre o trabalho realizado pelo g\u00e1s e o trabalho realizado com o g\u00e1s \u00e9 o trabalho l\u00edquido produzido pelo ciclo e corresponde \u00e0 \u00e1rea delimitada pela curva do ciclo.\u00a0O trabalho produzido pelos tempos de ciclo, a taxa do ciclo (ciclos por segundo) \u00e9 igual \u00e0 pot\u00eancia produzida pelo motor Atkinson.<\/span><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights  lgc-first\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>Processo isentr\u00f3pico<\/span><\/h2>\n<p><span>Um\u00a0<\/span><a title=\"Processo isentr\u00f3pico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-processo-isentropico-definicao\/\"><strong><span>processo isentr\u00f3pico<\/span><\/strong><\/a><span>\u00a0\u00e9 um\u00a0<\/span><a title=\"Processos termodin\u00e2micos\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-processo-termodinamico-definicao\/\"><strong><span>processo termodin\u00e2mico<\/span><\/strong><\/a><span>\u00a0, no qual a\u00a0<\/span><a title=\"O que \u00e9 entropia\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/what-is-energy-physics\/what-is-entropy\/\"><strong><span>entropia<\/span><\/strong>\u00a0<\/a><span>do fluido ou g\u00e1s permanece constante.\u00a0Isso significa que o\u00a0<\/span><strong><span>processo isentr\u00f3pico<\/span><\/strong><span>\u00a0\u00e9 um caso especial de um\u00a0<\/span><strong><span>processo adiab\u00e1tico<\/span><\/strong><span>\u00a0no qual n\u00e3o h\u00e1 transfer\u00eancia de calor ou mat\u00e9ria.\u00a0\u00c9 um\u00a0<\/span><strong><span>processo adiab\u00e1tico revers\u00edvel<\/span><\/strong><span>\u00a0.\u00a0A suposi\u00e7\u00e3o de que n\u00e3o h\u00e1 transfer\u00eancia de calor \u00e9 muito importante, pois podemos usar a aproxima\u00e7\u00e3o adiab\u00e1tica apenas em\u00a0<\/span><strong><span>processos muito r\u00e1pidos<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><strong><span>Processo isentr\u00f3pico e a primeira lei<\/span><\/strong><\/p>\n<p><span>Para um sistema fechado, podemos escrever a\u00a0<\/span><strong><a title=\"Primeira lei em termos de entalpia dH = dQ + Vdp\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/laws-of-thermodynamics\/first-law-of-thermodynamics\/first-law-in-terms-of-enthalpy-dh-dq-vdp\/\"><span>primeira lei da termodin\u00e2mica em termos de entalpia<\/span><\/a><\/strong><span>\u00a0:<\/span><\/p>\n<p><strong><span>dH = dQ + Vdp<\/span><\/strong><\/p>\n<p><strong><span>ou<\/span><\/strong><\/p>\n<p><strong><span>dH = TdS + Vdp<\/span><\/strong><\/p>\n<p><strong><span>Processo isentr\u00f3pico (dQ = 0):<\/span><\/strong><\/p>\n<p><strong><span>dH = Vdp \u2192 W = H\u00a0<\/span><\/strong><strong><sub><span>2<\/span><\/sub><\/strong><strong><span>\u00a0&#8211; H\u00a0<\/span><\/strong><strong><sub><span>1<\/span><\/sub><\/strong><strong><span>\u00a0\u00a0\u00a0\u00a0\u00a0\u2192 H\u00a0<\/span><\/strong><strong><sub><span>2<\/span><\/sub><\/strong><strong><span>\u00a0&#8211; H\u00a0<\/span><\/strong><strong><sub><span>1<\/span><\/sub><\/strong><strong><span>\u00a0=\u00a0<\/span><em><span>C\u00a0<\/span><\/em><\/strong><strong><em><sub><span>P<\/span><\/sub><\/em><\/strong><strong><em><span>\u00a0(T\u00a0<\/span><\/em><\/strong><strong><em><sub><span>2<\/span><\/sub><\/em><\/strong><strong><em><span>\u00a0&#8211; T\u00a0<\/span><\/em><\/strong><strong><em><sub><span>1<\/span><\/sub><\/em><\/strong><strong><em><span>\u00a0) \u00a0\u00a0\u00a0<\/span><\/em><\/strong><em><span>\u00a0(para\u00a0<\/span><a title=\"O que \u00e9 o g\u00e1s ideal\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/ideal-gas-law\/what-is-ideal-gas\/\"><span>g\u00e1s ideal<\/span><\/a><span>\u00a0)<\/span><\/em><\/p>\n<p><strong><span>Processo isentr\u00f3pico do g\u00e1s ideal<\/span><\/strong><\/p>\n<p><span>O\u00a0<\/span><strong><span>processo isentr\u00f3pico<\/span><\/strong><span>\u00a0(um caso especial de processo adiab\u00e1tico) pode ser expresso com a\u00a0<\/span><a title=\"Lei do g\u00e1s ideal\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/ideal-gas-law\/\"><strong><span>lei dos gases ideais<\/span><\/strong><\/a><span>\u00a0como:<\/span><\/p>\n<p><strong><em><span>pV\u00a0<\/span><sup><span>\u03ba<\/span><\/sup><span>\u00a0= constante<\/span><\/em><\/strong><\/p>\n<p><span>ou<\/span><\/p>\n<p><em><strong><span>p\u00a0<\/span><sub><span>1<\/span><\/sub><span>\u00a0V\u00a0<\/span><sub><span>1\u00a0<\/span><\/sub><sup><span>k<\/span><\/sup><span>\u00a0= p\u00a0<\/span><sub><span>2<\/span><\/sub><span>\u00a0V\u00a0<\/span><sub><span>2\u00a0<\/span><\/sub><sup><span>k<\/span><\/sup><\/strong><\/em><\/p>\n<p><span>em que\u00a0<\/span><strong><span>\u03ba = c\u00a0<\/span><sub><span>p<\/span><\/sub><span>\u00a0\/ c\u00a0<\/span><sub><span>v<\/span><\/sub><\/strong><span>\u00a0\u00e9 a propor\u00e7\u00e3o de\u00a0<a title=\"Capacidade t\u00e9rmica - Capacidade t\u00e9rmica espec\u00edfica\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/laws-of-thermodynamics\/first-law-of-thermodynamics\/heat-capacity\/\"><strong>aquecimentos espec\u00edficos<\/strong><\/a>\u00a0(ou\u00a0<strong>capacidades de calor<\/strong>\u00a0) para o g\u00e1s.\u00a0Um para\u00a0<strong>press\u00e3o constante (c\u00a0<\/strong><strong><sub>p<\/sub><\/strong><strong>\u00a0)<\/strong>\u00a0e outro para\u00a0<strong>volume constante (c\u00a0<\/strong><strong><sub>v<\/sub><\/strong><strong>\u00a0)<\/strong>\u00a0.\u00a0Observe que essa raz\u00e3o\u00a0<strong>\u03ba\u00a0\u00a0<\/strong><strong>= c\u00a0<\/strong><strong><sub>p<\/sub><\/strong><strong>\u00a0\/ c\u00a0<\/strong><strong><sub>v<\/sub><\/strong>\u00a0\u00e9 um fator na determina\u00e7\u00e3o da velocidade do som em um g\u00e1s e em outros processos adiab\u00e1ticos.<\/span><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>Processo Isoc\u00f3rico<\/span><\/h2>\n<p><span>Um\u00a0<\/span><a title=\"Processo Isoc\u00f3rico - Processo Isom\u00e9trico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-processo-isocorico-processo-isometrico-definicao\/\"><strong><span>processo isoc\u00f3rico<\/span><\/strong><\/a><span>\u00a0\u00e9 um processo termodin\u00e2mico, no qual o\u00a0<\/span><strong><span>volume<\/span><\/strong><span>\u00a0do sistema fechado\u00a0<\/span><strong><span>permanece constante<\/span><\/strong><span>\u00a0(V = const).\u00a0Ele descreve o comportamento do g\u00e1s dentro do recipiente, que n\u00e3o pode ser deformado.\u00a0Como o volume permanece constante, a transfer\u00eancia de calor para dentro ou para fora do sistema n\u00e3o\u00a0<\/span><a title=\"Trabalho p\u0394V - Trabalho de Fronteira e Trabalho V\u0394p\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/laws-of-thermodynamics\/first-law-of-thermodynamics\/p%ce%b4v-work-boundary-work-and-v%ce%b4p-work\/\"><span>funciona<\/span><\/a><span>\u00a0, mas altera apenas a\u00a0<\/span><a href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-energia-interna-energia-termica-definicao\/\"><strong><span>energia interna<\/span><\/strong><\/a><span>\u00a0(a temperatura) do sistema.<\/span><\/p>\n<p><strong><span>Processo isoc\u00f3rico e a primeira lei<\/span><\/strong><\/p>\n<p><span>A forma cl\u00e1ssica da\u00a0<\/span><a title=\"Primeira Lei da Termodin\u00e2mica\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-a-primeira-lei-da-termodinamica-definicao\/\"><span>primeira lei da termodin\u00e2mica<\/span><\/a><span>\u00a0\u00e9 a seguinte equa\u00e7\u00e3o:<\/span><\/p>\n<p><strong><span>dU = dQ &#8211; dW<\/span><\/strong><\/p>\n<p><span>Nesta equa\u00e7\u00e3o, dW \u00e9 igual a\u00a0<\/span><strong><span>dW = pdV<\/span><\/strong><span>\u00a0e \u00e9 conhecido como\u00a0<\/span><a title=\"Trabalho p\u0394V - Trabalho de Fronteira e Trabalho V\u0394p\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/laws-of-thermodynamics\/first-law-of-thermodynamics\/p%ce%b4v-work-boundary-work-and-v%ce%b4p-work\/\"><span>trabalho de fronteira<\/span><\/a><span>\u00a0.\u00a0Ent\u00e3o:<\/span><\/p>\n<p><strong><span>dU = dQ &#8211; pdV<\/span><\/strong><\/p>\n<p><span>No\u00a0<\/span><strong><span>processo isoc\u00f3rico<\/span><\/strong><span>\u00a0e no\u00a0<\/span><strong><span>g\u00e1s ideal<\/span><\/strong><span>\u00a0, todo o calor adicionado ao sistema ser\u00e1 usado para aumentar a energia interna.<\/span><\/p>\n<p><strong><span>Processo isoc\u00f3rico (pdV = 0):<\/span><\/strong><\/p>\n<p><strong><span>dU = dQ \u00a0\u00a0\u00a0\u00a0<\/span><\/strong><em><span>(para g\u00e1s ideal)<\/span><\/em><\/p>\n<p><strong><span>dU = 0 = Q &#8211; W \u2192 W = Q \u00a0\u00a0<\/span><em>\u00a0\u00a0\u00a0\u00a0<\/em><\/strong><em><span>(para g\u00e1s ideal)<\/span><\/em><\/p>\n<p><strong><span>Processo isoc\u00f3rico do g\u00e1s ideal<\/span><\/strong><\/p>\n<p><span>O\u00a0<\/span><strong><span>processo isoc\u00f3rico<\/span><\/strong><span>\u00a0pode ser expresso com a\u00a0<\/span><a title=\"Lei do g\u00e1s ideal\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/ideal-gas-law\/\"><strong><span>lei dos gases ideais<\/span><\/strong><\/a><span>\u00a0como:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isochoric-process-equation-1.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-17465 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isochoric-process-equation-1.png\" alt=\"processo isoc\u00f3rico - equa\u00e7\u00e3o 1\" width=\"138\" height=\"52\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isochoric-process-equation-1.png\" \/><\/a><\/p>\n<p><span>ou<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isochoric-process-equation-2.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-17466 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isochoric-process-equation-2.png\" alt=\"processo isoc\u00f3rico - equa\u00e7\u00e3o 2\" width=\"86\" height=\"66\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isochoric-process-equation-2.png\" \/><\/a><\/p>\n<p><span>Em um\u00a0<\/span><strong><span>diagrama pV<\/span><\/strong><span>\u00a0, o processo ocorre ao longo de uma linha horizontal que possui a equa\u00e7\u00e3o V = constante.<\/span><\/p>\n<p><span>Veja tamb\u00e9m:\u00a0\u00a0<\/span><a title=\"Lei de Guy-Lussac\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-a-lei-de-gay-lussac-definicao\/\"><span>Lei de Guy-Lussac<\/span><\/a><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights  lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>Processo isob\u00e1rico<\/span><\/h2>\n<p><span>Um\u00a0<\/span><strong><span>processo isob\u00e1rico<\/span><\/strong><span>\u00a0\u00e9 um\u00a0<\/span><a title=\"Processos termodin\u00e2micos\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-processo-termodinamico-definicao\/\"><span>processo termodin\u00e2mico<\/span><\/a><span>\u00a0, no qual a\u00a0<\/span><a title=\"O que \u00e9 press\u00e3o - F\u00edsica\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/thermodynamic-properties\/what-is-pressure-physics\/\"><strong><span>press\u00e3o<\/span><\/strong><\/a><span>\u00a0do sistema\u00a0<\/span><strong><span>permanece constante<\/span><\/strong><span>\u00a0(p = const).\u00a0A transfer\u00eancia de calor para dentro ou para fora do sistema funciona, mas tamb\u00e9m altera a energia interna do sistema.<\/span><\/p>\n<p><span>Como existem mudan\u00e7as na\u00a0<\/span><a href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-energia-interna-energia-termica-definicao\/\"><span>energia interna<\/span><\/a><span>\u00a0(dU) e no volume do sistema (\u2206V), os engenheiros costumam usar a\u00a0<\/span><a title=\"O que \u00e9 entalpia\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/what-is-energy-physics\/what-is-enthalpy\/\"><strong><span>entalpia<\/span><\/strong><\/a><span>\u00a0do sistema, que \u00e9 definida como:<\/span><\/p>\n<p><em><strong><span>H = U + pV<\/span><\/strong><\/em><\/p>\n<p><strong><span>Processo isob\u00e1rico e a primeira lei<\/span><\/strong><\/p>\n<p><span>A forma cl\u00e1ssica da\u00a0<\/span><a title=\"Primeira Lei da Termodin\u00e2mica\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-a-primeira-lei-da-termodinamica-definicao\/\"><span>primeira lei da termodin\u00e2mica<\/span><\/a><span>\u00a0\u00e9 a seguinte equa\u00e7\u00e3o:<\/span><\/p>\n<p><strong><span>dU = dQ &#8211; dW<\/span><\/strong><\/p>\n<p><span>Nesta equa\u00e7\u00e3o, dW \u00e9 igual a\u00a0<\/span><strong><span>dW = pdV<\/span><\/strong><span>\u00a0e \u00e9 conhecido como\u00a0<\/span><a title=\"Trabalho p\u0394V - Trabalho de Fronteira e Trabalho V\u0394p\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/laws-of-thermodynamics\/first-law-of-thermodynamics\/p%ce%b4v-work-boundary-work-and-v%ce%b4p-work\/\"><span>trabalho de fronteira<\/span><\/a><span>\u00a0.\u00a0Em um processo isob\u00e1rico e no g\u00e1s ideal,\u00a0<\/span><strong><span>parte do calor adicionado<\/span><\/strong><span>\u00a0ao sistema ser\u00e1 usada para\u00a0<\/span><strong><span>realizar o trabalho<\/span><\/strong><span>\u00a0e\u00a0<\/span><strong><span>parte do calor<\/span><\/strong><span>\u00a0adicionado aumentar\u00e1 a\u00a0<\/span><a href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-energia-interna-energia-termica-definicao\/\"><strong><span>energia interna<\/span><\/strong><\/a><span>\u00a0(aumentar\u00e1 a temperatura).\u00a0Portanto, \u00e9 conveniente usar a\u00a0<\/span><strong><span>entalpia em<\/span><\/strong><span>\u00a0vez da energia interna.<\/span><\/p>\n<p><strong><span>Processo isob\u00e1rico (Vdp = 0):<\/span><\/strong><\/p>\n<p><strong><span>dH = dQ \u2192 Q = H\u00a0<\/span><\/strong><strong><sub><span>2<\/span><\/sub><\/strong><strong><span>\u00a0&#8211; H\u00a0<\/span><\/strong><strong><sub><span>1<\/span><\/sub><\/strong><\/p>\n<p><strong><span>Na entropia constante<\/span><\/strong><span>\u00a0, ou seja, no processo isentr\u00f3pico, a\u00a0<\/span><strong><span>mudan\u00e7a de entalpia<\/span><\/strong><span>\u00a0\u00e9 igual ao\u00a0<\/span><strong><span>trabalho do processo de fluxo<\/span><\/strong><span>\u00a0realizado no sistema ou pelo mesmo.<\/span><\/p>\n<p><strong><span>Processo isob\u00e1rico do g\u00e1s ideal<\/span><\/strong><\/p>\n<p><span>O\u00a0<\/span><strong><span>processo isob\u00e1rico<\/span><\/strong><span>\u00a0pode ser expresso com a\u00a0<\/span><a title=\"Lei do g\u00e1s ideal\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/ideal-gas-law\/\"><strong><span>lei do g\u00e1s ideal<\/span><\/strong><\/a><span>\u00a0como:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isobaric-process-equation-2.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-17430 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isobaric-process-equation-2.png\" alt=\"processo isob\u00e1rico - equa\u00e7\u00e3o - 2\" width=\"134\" height=\"63\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isobaric-process-equation-2.png\" \/><\/a><\/p>\n<p><span>ou<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isobaric-process-equation-3.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-17431 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isobaric-process-equation-3.png\" alt=\"processo isob\u00e1rico - equa\u00e7\u00e3o - 3\" width=\"77\" height=\"67\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/isobaric-process-equation-3.png\" \/><\/a><\/p>\n<p><span>Em um\u00a0<\/span><strong><span>diagrama de pV<\/span><\/strong><span>\u00a0, o processo ocorre ao longo de uma linha horizontal (chamada isobar) que possui a equa\u00e7\u00e3o p = constante.<\/span><\/p>\n<p><span>Veja tamb\u00e9m:\u00a0<\/span><a title=\"Lei de Charles\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-a-lei-de-charles-definicao\/\"><span>Lei de Charles<\/span><\/a><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights  lgc-first\">\n<div class=\"inside-grid-column\">\n<figure id=\"attachment_17280\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-17280\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Isentropic-Process-characteristics.png\"><img loading=\"lazy\" class=\"size-full wp-image-17280 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Isentropic-Process-characteristics.png\" alt=\"Processo isentr\u00f3pico - caracter\u00edsticas\" width=\"386\" height=\"609\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Isentropic-Process-characteristics.png\" \/><\/a><figcaption id=\"caption-attachment-17280\" class=\"wp-caption-text\"><span>Processo isentr\u00f3pico &#8211; principais caracter\u00edsticas<\/span><\/figcaption><\/figure>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \">\n<div class=\"inside-grid-column\">\n<figure id=\"attachment_17463\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-17463\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Isochoric-process-main-characteristics.png\"><img loading=\"lazy\" class=\"size-full wp-image-17463 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Isochoric-process-main-characteristics.png\" alt=\"Processo isoc\u00f3rico - principais caracter\u00edsticas\" width=\"382\" height=\"468\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Isochoric-process-main-characteristics.png\" \/><\/a><figcaption id=\"caption-attachment-17463\" class=\"wp-caption-text\"><span>Processo isoc\u00f3rico &#8211; principais caracter\u00edsticas<\/span><\/figcaption><\/figure>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights  lgc-last\">\n<div class=\"inside-grid-column\">\n<figure id=\"attachment_17426\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-17426\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Isobaric-process-main-characteristics.png\"><img loading=\"lazy\" class=\"size-full wp-image-17426 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Isobaric-process-main-characteristics.png\" alt=\"Processo isob\u00e1rico - principais caracter\u00edsticas\" width=\"381\" height=\"717\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Isobaric-process-main-characteristics.png\" \/><\/a><figcaption id=\"caption-attachment-17426\" class=\"wp-caption-text\"><span>Processo isob\u00e1rico &#8211; principais caracter\u00edsticas<\/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>Efici\u00eancia t\u00e9rmica para o ciclo de Atkinson<\/span><\/h2>\n<p><span>Em geral, a\u00a0<a title=\"Efici\u00eancia t\u00e9rmica\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-eficiencia-termica-definicao\/\"><strong>efici\u00eancia t\u00e9rmica<\/strong><\/a><a title=\"Efici\u00eancia t\u00e9rmica\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-eficiencia-termica-definicao\/\">\u00a0,\u00a0<\/a><a title=\"Efici\u00eancia t\u00e9rmica\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-eficiencia-termica-definicao\/\"><strong><em>\u03b7\u00a0<\/em><\/strong><\/a><a title=\"Efici\u00eancia t\u00e9rmica\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-eficiencia-termica-definicao\/\"><strong><em><sub>th<\/sub><\/em><\/strong><\/a>\u00a0, de qualquer motor de calor \u00e9 definida como a raz\u00e3o entre o\u00a0<a href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-trabalho-em-termodinamica-definicao\/\">trabalho<\/a>\u00a0que faz,\u00a0<strong>W<\/strong>\u00a0, para o\u00a0<a href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-calor-na-fisica-calor-definicao\/\">calor<\/a>\u00a0de entrada a uma temperatura elevada, Q\u00a0<sub>H<\/sub>\u00a0.<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/thermal-efficiency-formula-1.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-16945 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/thermal-efficiency-formula-1.png\" alt=\"f\u00f3rmula de efici\u00eancia t\u00e9rmica - 1\" width=\"125\" height=\"82\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/thermal-efficiency-formula-1.png\" \/><\/a><\/p>\n<p><span>A\u00a0<\/span><strong><span>efici\u00eancia t\u00e9rmica<\/span><\/strong><span>\u00a0,\u00a0<\/span><strong><em><span>\u03b7\u00a0<\/span><\/em><\/strong><strong><em><sub><span>th<\/span><\/sub><\/em><\/strong><span>\u00a0, representa a fra\u00e7\u00e3o de\u00a0<\/span><strong><span>calor<\/span><\/strong><span>\u00a0,\u00a0<\/span><strong><span>Q\u00a0<\/span><\/strong><strong><sub><span>H<\/span><\/sub><\/strong><span>\u00a0, que \u00e9 convertida\u00a0<\/span><strong><span>em trabalho<\/span><\/strong><span>\u00a0.\u00a0Como a energia \u00e9 conservada de acordo com a\u00a0<\/span><a href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-a-primeira-lei-da-termodinamica-definicao\/\"><strong><span>primeira lei da termodin\u00e2mica<\/span><\/strong><\/a><span>\u00a0e a energia n\u00e3o pode ser convertida para funcionar completamente, a entrada de calor, Q\u00a0<\/span><sub><span>H<\/span><\/sub><span>\u00a0, deve ser igual ao trabalho realizado, W, mais o calor que deve ser dissipado como\u00a0<\/span><strong><span>calor residual Q\u00a0<\/span><\/strong><strong><sub><span>C<\/span><\/sub><\/strong><span>\u00a0no meio Ambiente.\u00a0Portanto, podemos reescrever a f\u00f3rmula da efici\u00eancia t\u00e9rmica como:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/thermal-efficiency-formula-2.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-16944 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/thermal-efficiency-formula-2.png\" alt=\"f\u00f3rmula de efici\u00eancia t\u00e9rmica - 2\" width=\"352\" height=\"83\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/thermal-efficiency-formula-2.png\" \/><\/a><\/p>\n<p><span>O calor absorvido ocorre durante a combust\u00e3o da mistura combust\u00edvel-ar, quando a fa\u00edsca ocorre, aproximadamente a volume constante.\u00a0Como durante um\u00a0<\/span><a title=\"Processo Isoc\u00f3rico - Processo Isom\u00e9trico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-processo-isocorico-processo-isometrico-definicao\/\"><span>processo isoc\u00f3rico<\/span><\/a><span>\u00a0n\u00e3o h\u00e1 trabalho realizado pelo sistema ou sobre ele, a\u00a0<\/span><strong><span>primeira lei da termodin\u00e2mica<\/span><\/strong><span>\u00a0determina\u00a0<\/span><em><span>\u2206U = \u2206Q.<\/span><\/em><\/p>\n<p><span>Portanto, o calor adicionado e rejeitado \u00e9 dado por:<\/span><\/p>\n<p><span>Q\u00a0<\/span><sub><span>add<\/span><\/sub><span>\u00a0= mc\u00a0<\/span><sub><span>v<\/span><\/sub><span>\u00a0(T\u00a0<\/span><sub><span>3<\/span><\/sub><span>\u00a0&#8211; T\u00a0<\/span><sub><span>2<\/span><\/sub><span>\u00a0)<\/span><\/p>\n<p><span>Q\u00a0<\/span><sub><span>out<\/span><\/sub><span>\u00a0= mc\u00a0<\/span><sub><span>p<\/span><\/sub><span>\u00a0(T\u00a0<\/span><sub><span>4<\/span><\/sub><span>\u00a0&#8211; T\u00a0<\/span><sub><span>1<\/span><\/sub><span>\u00a0)<\/span><\/p>\n<p><span>Substituindo essas express\u00f5es pelo calor adicionado e rejeitado na express\u00e3o por efici\u00eancia t\u00e9rmica, obt\u00e9m-se:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-cycle-thermal-efficiency.png\"><img loading=\"lazy\" class=\"lazy-hidden aligncenter size-full wp-image-17623\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-cycle-thermal-efficiency.png\" alt=\"Ciclo de Atkinson - efici\u00eancia t\u00e9rmica\" width=\"197\" height=\"65\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-cycle-thermal-efficiency.png\" \/><\/a><\/p>\n<p><span>Al\u00e9m disso, pode-se derivar isso em termos de:<\/span><\/p>\n<ul>\n<li><span>a raz\u00e3o V\u00a0<\/span><sub><span>1<\/span><\/sub><span>\u00a0\/ V\u00a0<\/span><sub><span>2<\/span><\/sub><span>\u00a0, que \u00e9 conhecida como taxa de compress\u00e3o &#8211; CR<\/span><\/li>\n<li><span>a raz\u00e3o V\u00a0<\/span><sub><span>4<\/span><\/sub><span>\u00a0\/ V\u00a0<\/span><sub><span>3<\/span><\/sub><span>\u00a0, que \u00e9 conhecida como taxa de expans\u00e3o &#8211; ER.<\/span><\/li>\n<li><strong><span>\u03ba = c\u00a0<\/span><\/strong><strong><sub><span>p<\/span><\/sub><\/strong><strong><span>\u00a0\/ c\u00a0<\/span><\/strong><strong><sub><span>v<\/span><\/sub><\/strong><\/li>\n<\/ul>\n<p><span>A express\u00e3o para efici\u00eancia t\u00e9rmica usando essas caracter\u00edsticas \u00e9:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-cycle-thermal-efficiency2.png\"><img loading=\"lazy\" class=\"lazy-hidden aligncenter size-full wp-image-17624\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-cycle-thermal-efficiency2.png\" alt=\"Ciclo de Atkinson - efici\u00eancia t\u00e9rmica2\" width=\"236\" height=\"70\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Atkinson-cycle-thermal-efficiency2.png\" \/><\/a><\/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>\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>Ciclo de Atkinson &#8211; motor de Atkinson.\u00a0O ciclo de Atkinson \u00e9 um ciclo termodin\u00e2mico projetado para fornecer maior efici\u00eancia \u00e0s custas da densidade de pot\u00eancia.\u00a0Engenharia T\u00e9rmica Ciclo de Atkinson &#8211; Atkinson Engine Em 1882, um engenheiro brit\u00e2nico,\u00a0James\u00a0Atkinson,\u00a0avan\u00e7ou no estudo de motores t\u00e9rmicos, inventando v\u00e1rios\u00a0motores t\u00e9rmicos\u00a0que tiveram uma efici\u00eancia aumentada ao longo do\u00a0ciclo Otto\u00a0.\u00a0Isso foi alcan\u00e7ado &#8230; <a title=\"O que \u00e9 o Ciclo de Atkinson &#8211; Atkinson Engine &#8211; Defini\u00e7\u00e3o\" class=\"read-more\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-atkinson-atkinson-engine-definicao\/\" aria-label=\"More on O que \u00e9 o Ciclo de Atkinson &#8211; Atkinson Engine &#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 o Ciclo de Atkinson - Atkinson Engine - Defini\u00e7\u00e3o<\/title>\n<meta name=\"description\" content=\"Ciclo de Atkinson - motor de Atkinson. 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