Nitul Kalita, Himangshu Kumar, Rupam Shankar Nath, Rudra Kanta Deka
{"title":"存在热分层和化学反应的脉冲式启动的无限垂直板上的非稳态流动","authors":"Nitul Kalita, Himangshu Kumar, Rupam Shankar Nath, Rudra Kanta Deka","doi":"10.1002/htj.23137","DOIUrl":null,"url":null,"abstract":"<p>The purpose of this study is to analyze how thermal stratification affects fluid movement past an impulsively initiated infinite upright plate when first-order chemical reactions are present. Laplace's transform method is applied to achieve a closed-form solution for the nondimensional governing equations when <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>P</mi>\n \n <mi>r</mi>\n \n <mo>=</mo>\n \n <mn>1</mn>\n </mrow>\n </mrow>\n </semantics></math>. The formula <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>L</mi>\n \n <mrow>\n <mo>{</mo>\n \n <mrow>\n <mi>n</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>t</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n \n <mo>}</mo>\n </mrow>\n \n <mo>=</mo>\n \n <msubsup>\n <mo>∫</mo>\n \n <mn>0</mn>\n \n <mi>∞</mi>\n </msubsup>\n \n <msup>\n <mi>e</mi>\n \n <mrow>\n <mo>−</mo>\n \n <mi>s</mi>\n \n <mi>t</mi>\n </mrow>\n </msup>\n \n <mi>n</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>t</mi>\n \n <mo>)</mo>\n </mrow>\n \n <mi>d</mi>\n \n <mi>t</mi>\n \n <mo>=</mo>\n \n <mover>\n <mi>n</mi>\n \n <mo>¯</mo>\n </mover>\n \n <mrow>\n <mo>(</mo>\n \n <mi>s</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n </mrow>\n </semantics></math>, where <i>t</i> is the time and <i>s</i> is a parameter, can be used to obtain the Laplace transform of an exponentially ordered piece-wise continuous function <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>n</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>t</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n </mrow>\n </semantics></math>. The unstable flow past an infinite vertical plate, starting abruptly in the presence of heat stratification and chemical reactions, has never been studied before. The research focuses on the combined impact of thermal stratification and chemical processes on the flow of an incompressible viscous fluid over an indefinitely tall plate. In this study, the significant findings that resulted from heat stratification are compared to the condition in which heat stratification is absent. The impacts of a number of parameters, such as <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>S</mi>\n \n <mo>,</mo>\n \n <mi>K</mi>\n \n <mo>,</mo>\n \n <mi>G</mi>\n \n <mi>r</mi>\n \n <mo>,</mo>\n \n <mo> </mo>\n \n <mi>and</mi>\n \n <mo> </mo>\n \n <mi>G</mi>\n \n <mi>c</mi>\n \n <mo>,</mo>\n </mrow>\n </mrow>\n </semantics></math> are investigated and visually displayed with respect to the following variables: concentration, velocity, shear stress, rate of heat transfer, temperature, and rate of mass transfer. It is demonstrated that applying stratification increases the frequency of oscillation in shear stress and heat transfer rate. The results obtained can be useful in the design of heat exchangers and other engineering applications.</p>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"53 8","pages":"4316-4338"},"PeriodicalIF":2.8000,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Unsteady flow past an impulsively started infinite vertical plate in presence of thermal stratification and chemical reaction\",\"authors\":\"Nitul Kalita, Himangshu Kumar, Rupam Shankar Nath, Rudra Kanta Deka\",\"doi\":\"10.1002/htj.23137\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The purpose of this study is to analyze how thermal stratification affects fluid movement past an impulsively initiated infinite upright plate when first-order chemical reactions are present. Laplace's transform method is applied to achieve a closed-form solution for the nondimensional governing equations when <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>P</mi>\\n \\n <mi>r</mi>\\n \\n <mo>=</mo>\\n \\n <mn>1</mn>\\n </mrow>\\n </mrow>\\n </semantics></math>. The formula <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>L</mi>\\n \\n <mrow>\\n <mo>{</mo>\\n \\n <mrow>\\n <mi>n</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>t</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n \\n <mo>}</mo>\\n </mrow>\\n \\n <mo>=</mo>\\n \\n <msubsup>\\n <mo>∫</mo>\\n \\n <mn>0</mn>\\n \\n <mi>∞</mi>\\n </msubsup>\\n \\n <msup>\\n <mi>e</mi>\\n \\n <mrow>\\n <mo>−</mo>\\n \\n <mi>s</mi>\\n \\n <mi>t</mi>\\n </mrow>\\n </msup>\\n \\n <mi>n</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>t</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mi>d</mi>\\n \\n <mi>t</mi>\\n \\n <mo>=</mo>\\n \\n <mover>\\n <mi>n</mi>\\n \\n <mo>¯</mo>\\n </mover>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>s</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n </mrow>\\n </semantics></math>, where <i>t</i> is the time and <i>s</i> is a parameter, can be used to obtain the Laplace transform of an exponentially ordered piece-wise continuous function <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>n</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>t</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n </mrow>\\n </semantics></math>. The unstable flow past an infinite vertical plate, starting abruptly in the presence of heat stratification and chemical reactions, has never been studied before. The research focuses on the combined impact of thermal stratification and chemical processes on the flow of an incompressible viscous fluid over an indefinitely tall plate. In this study, the significant findings that resulted from heat stratification are compared to the condition in which heat stratification is absent. The impacts of a number of parameters, such as <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>S</mi>\\n \\n <mo>,</mo>\\n \\n <mi>K</mi>\\n \\n <mo>,</mo>\\n \\n <mi>G</mi>\\n \\n <mi>r</mi>\\n \\n <mo>,</mo>\\n \\n <mo> </mo>\\n \\n <mi>and</mi>\\n \\n <mo> </mo>\\n \\n <mi>G</mi>\\n \\n <mi>c</mi>\\n \\n <mo>,</mo>\\n </mrow>\\n </mrow>\\n </semantics></math> are investigated and visually displayed with respect to the following variables: concentration, velocity, shear stress, rate of heat transfer, temperature, and rate of mass transfer. It is demonstrated that applying stratification increases the frequency of oscillation in shear stress and heat transfer rate. The results obtained can be useful in the design of heat exchangers and other engineering applications.</p>\",\"PeriodicalId\":44939,\"journal\":{\"name\":\"Heat Transfer\",\"volume\":\"53 8\",\"pages\":\"4316-4338\"},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2024-07-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Heat Transfer\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/htj.23137\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"THERMODYNAMICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Heat Transfer","FirstCategoryId":"1085","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/htj.23137","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"THERMODYNAMICS","Score":null,"Total":0}
Unsteady flow past an impulsively started infinite vertical plate in presence of thermal stratification and chemical reaction
The purpose of this study is to analyze how thermal stratification affects fluid movement past an impulsively initiated infinite upright plate when first-order chemical reactions are present. Laplace's transform method is applied to achieve a closed-form solution for the nondimensional governing equations when . The formula , where t is the time and s is a parameter, can be used to obtain the Laplace transform of an exponentially ordered piece-wise continuous function . The unstable flow past an infinite vertical plate, starting abruptly in the presence of heat stratification and chemical reactions, has never been studied before. The research focuses on the combined impact of thermal stratification and chemical processes on the flow of an incompressible viscous fluid over an indefinitely tall plate. In this study, the significant findings that resulted from heat stratification are compared to the condition in which heat stratification is absent. The impacts of a number of parameters, such as are investigated and visually displayed with respect to the following variables: concentration, velocity, shear stress, rate of heat transfer, temperature, and rate of mass transfer. It is demonstrated that applying stratification increases the frequency of oscillation in shear stress and heat transfer rate. The results obtained can be useful in the design of heat exchangers and other engineering applications.