Computational Thermal Sciences最新文献

Simulating Spray Dynamics with a Finite Element Method for Internal Combustion Engines using Large Eddy Simulations 基于大涡模拟的内燃机喷雾动力学有限元模拟

Computational Thermal Sciences Pub Date : 2023-01-01 DOI: 10.1615/computthermalscien.2023048363

David Carrington, Jiajia Waters

{"title":"Simulating Spray Dynamics with a Finite Element Method for Internal Combustion Engines using Large Eddy Simulations","authors":"David Carrington, Jiajia Waters","doi":"10.1615/computthermalscien.2023048363","DOIUrl":"https://doi.org/10.1615/computthermalscien.2023048363","url":null,"abstract":"Spray dynamics in an internal combustion engine is comprised of complex phenomena while interacting with unsteady turbulence. The physics requires detailed modeling of the dynamics for spray and carrier gases to accurately predict a spray’s fate. Large Eddy Simulation (LES) turbulence modeling approaches are capable predictors of the turbulent processes and are capable of dynamically modeling sub-grid scales, therefore enabling calculation of model coefficients for the smallest resolved scale. Dynamic LES methods are also well suited for unsteady flows associated with spray injection and engine fluid dynamics. In this study, for the first time, a dynamic Verman LES scheme employed, in a stabilized a finite element framework, is used to model the spray process with emphasis on injected fuels for simulating internal combustion engines. Spray modeling often comprises a coupled Eulerian-Lagrangian approach to capture the droplet/particle dynamics, where the droplets are modeled in the Lagrangian frame. The momentum and heat exchange between the fluid gases and the evaporating and atomizing spray droplets are modeled in a two-way coupling system as described in this paper. Direct injected liquid is modeled in this paper as a spherical ligament of fuel and ligament break-up to atomization use our version of the Kelvin Helmholtz break-up scheme. Discussed are models and methods of the whole system in some detail, the method for simulation of the fluid’s momentum, heat transfer and turbulence are discussed as is the system to evaluate droplet or ligament properties. Validation or results of the modeling are presented on test cases as determined by Engine Combustion Network (E","PeriodicalId":45052,"journal":{"name":"Computational Thermal Sciences","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135559422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unsteady mixed convection hydromagnetic Casson thermodiffusion flow of reacting and dissipating fluid with an inclined magnetic field along an oscillating slanted porous plate 斜磁场作用下反应和耗散流体沿振荡斜多孔板的非定常混合对流流体磁卡森热扩散流动

Computational Thermal Sciences Pub Date : 2023-01-01 DOI: 10.1615/computthermalscien.2023050323

A. Jackson Kobia, B. Prabhakar Reddy, P. M. Matao

{"title":"Unsteady mixed convection hydromagnetic Casson thermodiffusion flow of reacting and dissipating fluid with an inclined magnetic field along an oscillating slanted porous plate","authors":"A. Jackson Kobia, B. Prabhakar Reddy, P. M. Matao","doi":"10.1615/computthermalscien.2023050323","DOIUrl":"https://doi.org/10.1615/computthermalscien.2023050323","url":null,"abstract":"A finite element numerical simulation is undertaken to explore the aspects of angled magnetic field and thermo-diffusion on an unsteady reacting mixed convection flow of hydro-magnetic Casson dissipating fluid with thermal radiation. The fluid streams across an oscillating tilted plate ingrained in a porous medium including time altering temperature and concentration. The dimensionless flow guiding partial differential equations along their associated initial and boundary conditions are handled enforcing an efficient finite element scheme. The key parameters affecting the velocity, temperature, and concentration profiles are comprehensively interpreted through graphical representations while the skin friction, heat transfer, and mass transfer rates outlined via tables. The ultimate results of this study posted that the plate inclination angle, Casson parameter, and applied magnetic strengths are compelled to impede the fluid velocity and local skin friction whereas the porosity parameter displays a reverse effect. The thermo-diffusion effect amplifies the fluid velocity and species concentration. It also supported that the Eckert number and heat source boost up the velocity and temperature profiles. Moreover, increasing radiation parameter and time crusade an upsurge the Nusselt number. The chemical reaction quickens the Sherwood number but it decays with the thermo-diffusion parameter. A comparative analysis between the current findings and existing research works in the literature demonstrates the results’ precision and exactitude.","PeriodicalId":45052,"journal":{"name":"Computational Thermal Sciences","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135659971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Landau Legendre Wavelet Galerkin Method Applied to Study Two Phase Moving Boundary Problem of Heat Transfer in Finite Region 应用朗道-勒让德小波伽辽金方法研究有限区域内传热的两相移动边界问题

Computational Thermal Sciences Pub Date : 2023-01-01 DOI: 10.1615/computthermalscien.2023046663

Subrahamanyam Upadhyay, Priti Sharma, Harpreet Kaur, Kavindra Nath Rai, Anand Chauhan

{"title":"Landau Legendre Wavelet Galerkin Method Applied to Study Two Phase Moving Boundary Problem of Heat Transfer in Finite Region","authors":"Subrahamanyam Upadhyay, Priti Sharma, Harpreet Kaur, Kavindra Nath Rai, Anand Chauhan","doi":"10.1615/computthermalscien.2023046663","DOIUrl":"https://doi.org/10.1615/computthermalscien.2023046663","url":null,"abstract":"In this paper, we developed a mathematical model of solidification where specific heat and thermal conductivity are temperature dependent. This model is a two-phase MBP of heat transfer in finite region and represents as MBP of system of parabolic non-linear second order PDEs. We developed a Landau Legendre Wavelet Galerkin Method for finding the solution of the problem. The MBP of a system of PDEs is transformed into a variable boundary value problem of non-linear ODEs by the use of dimensionless variables and the Landau transform. The problem is converted into system of algebraic equations with the application of Legendre Wavelet Galerkin Method. In particular case, we compared present solution with Laplace transform solution and found approximately same. The whole investigation has been done in dimensionless form. When the specific heat and thermal conductivity exponentially varies in temperatures, the effect of dimensionless parameters: Thermal diffusivity $(alpha_{12})$, ratio of Thermal conductivity $(k_{12})$, dimensionless temperature $(theta_{f})$, Fourier number $(F_0)$,Stefan number $(Ste)$ and ratio of densities $left(rho_{1}/rho_{2} right)$ are discussed in detail.","PeriodicalId":45052,"journal":{"name":"Computational Thermal Sciences","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135550423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Primary Breakup Instability of Liquid Jet in Crossflow 横流中液体射流的初次破裂不稳定性

Computational Thermal Sciences Pub Date : 2023-01-01 DOI: 10.1615/computthermalscien.2023048933

Bharat Bhatia, Tom Johny, Ashoke De

引用次数: 0

Validation of Computational Modeling of Complex Thermal Processes and Systems: A Tribute to Professor Darrell Pepper 复杂热过程和系统的计算模型的验证:向达雷尔·佩珀教授致敬

Computational Thermal Sciences Pub Date : 2023-01-01 DOI: 10.1615/computthermalscien.2023049306

Yogesh Jaluria

引用次数: 0

TWO MEMBERS OF THE EDITORIAL BOARD RECEIVE AWARDS FROM THE INTERNATIONAL CENTRE FOR HEAT AND MASS TRANSFER (ICHMT) 两名编委会成员获得国际热质传递中心(ichmt)颁发的奖项。

Computational Thermal Sciences Pub Date : 2023-01-01 DOI: 10.1615/computthermalscien.2023049471

Wilson Chiu, HELCIO ORLANDE

引用次数: 0

COUPLED EFFECT OF VARIABLE WETTABILITY AND BODY FORCE ON FLUID FLOW THROUGH NANOCHANNELS: A MULTISCALE APPROACH 可变润湿性和身体力对纳米通道流体流动的耦合效应:多尺度方法

Computational Thermal Sciences Pub Date : 2023-01-01 DOI: 10.1615/computthermalscien.2022043262

Abhirup Chaudhuri, Vinay Arya, Chirodeep Bakli

{"title":"COUPLED EFFECT OF VARIABLE WETTABILITY AND BODY FORCE ON FLUID FLOW THROUGH NANOCHANNELS: A MULTISCALE APPROACH","authors":"Abhirup Chaudhuri, Vinay Arya, Chirodeep Bakli","doi":"10.1615/computthermalscien.2022043262","DOIUrl":"https://doi.org/10.1615/computthermalscien.2022043262","url":null,"abstract":"Fluid flow through sub-micron domains has been an area of active research in recent years with immense scientific and technological interests. Such flows can show deviation in behavior from the theories of classical hydrodynamics, thus opening up a new paradigm to exploit these unique effects in applications related to transport and detection. By performing extensive molecular-dynamics (MD) simulations of fluid flow through a parallel plate nanochannel of non-uniform wetting characteristics, we bring out the coupled effect of surface wettability and applied body force on interfacial slip. Our results reveal distinctive slip-stick alteration which can be useful in designing channels with engineered effective slip. Moreover, in this study, we revisit a hybrid molecular-continuum multiscale model which can significantly reduce the computational cost of full-scale MD simulations and further provide a framework to discern the flow behavior for a wide spectrum of length scales. The results obtained from this study may provide useful insights, thus carrying immense implications towards designing of multifaceted nanoscale devices and futuristic smart surfaces.","PeriodicalId":45052,"journal":{"name":"Computational Thermal Sciences","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135237085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Root Exudation of Specialized Molecules for Plant-Environment Interaction. 根系渗出植物与环境互动的特殊分子

IF 1.2

Computational Thermal Sciences Pub Date : 2022-11-30 DOI: 10.2533/chimia.2022.922

Sergio Rasmann, Ivan Hiltpold

{"title":"Root Exudation of Specialized Molecules for Plant-Environment Interaction.","authors":"Sergio Rasmann, Ivan Hiltpold","doi":"10.2533/chimia.2022.922","DOIUrl":"10.2533/chimia.2022.922","url":null,"abstract":"<p><p>It has been estimated that between 40 and 60 % of the assimilated carbon is diverted to the roots and released in the rhizosphere in form of root exudates. Root exudates thus define a complex mixture of low and high molecular weight compounds, including carbohydrates, amino acids, organic, and proteins, but also a broad spectrum of specialized molecules, such as flavonoids, glucosinolates, terpenoids, or alkaloids. Root exudates favour soil mineral nutrition, can bind to soil aggregate and in turn modify soil physico-chemical properties, but also mediate plant-plant, plant-microbe, and plant-animal interactions belowground. With this review, we aim to highlight how chemical ecologists have approached the study of root exudates-mediated interactions between plants and their biotic and abiotic surroundings. We do so by presenting a series of study cases for, on one hand, showcasing different methodologies that have been developed to test the activity of different root exudates, and, on the other hand, to show the broad array of interactions mediated by root exudates. Ultimately, we aim to spur further research and collaborations between chemists and ecologists studying belowground chemically-mediated interactions, so as to tackle essential challenges in terms of food security and climate change in the near future.</p>","PeriodicalId":45052,"journal":{"name":"Computational Thermal Sciences","volume":"2 1","pages":"922-927"},"PeriodicalIF":1.2,"publicationDate":"2022-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89535270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Modelling of liquid drop heating and evaporation: the effect of drop shrinking 液滴加热和蒸发的模拟:液滴收缩的影响

IF 1.5

Computational Thermal Sciences Pub Date : 2018-01-01 DOI: 10.1615/COMPUTTHERMALSCIEN.2018021330

S. Tonini, G. Cossali

引用次数: 3

Joint influence of high entropy layer and goertler vortices on heat transfer in supersonic compression ramp flow 超声速压缩斜流中高熵层和控制涡对换热的联合影响

IF 1.5

Computational Thermal Sciences Pub Date : 2016-01-01 DOI: 10.1615/COMPUTTHERMALSCIEN.2016018947

P. Chuvakhov, H. Olivier, I. Egorov, A. Roghelia

引用次数: 7