Heat Transfer Research最新文献_第7页

Validating the First Law of Thermodynamics for Unsteady Flow in a Compression Wave Using Mathcad 用Mathcad验证压缩波非定常流动热力学第一定律

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2023-11-01 DOI: 10.1615/heattransres.2023051072

Vladimir Ryndin, Amangeldy Karmanov, Akmaral Kinzhibekova, Rizagul Dyussova, Gulnara Abdullina

{"title":"Validating the First Law of Thermodynamics for Unsteady Flow in a Compression Wave Using Mathcad","authors":"Vladimir Ryndin, Amangeldy Karmanov, Akmaral Kinzhibekova, Rizagul Dyussova, Gulnara Abdullina","doi":"10.1615/heattransres.2023051072","DOIUrl":"https://doi.org/10.1615/heattransres.2023051072","url":null,"abstract":"Classical thermodynamics traditionally overlooks the role of quantities dependent on spatial coordinates and time, especially in the context of unsteady flows. This research introduces the first law of thermodynamics (FLT) tailored for non-stationary flow, distinguishing itself with the inclusion of terms bearing partial derivatives of pressure, p(x, t), concerning coordinates and time (–υ(∂р/∂х)dx; –υ(∂р/∂t)dt). By employing this novel approach, the derived equations are validated using a centred compression wave as a representative non-stationary flow case study. A methodology is also presented for experimentally quantifying hydrodynamic energy losses in the intake and exhaust systems of internal combustion engines. Central to the exploration is the calculation of pressure forces' work –υ(∂р/∂х)dx and –υ(∂р/∂t)dt) in the FLT equation for non-stationary flows, particularly their applicability to a centred compression wave. Moreover, a distinct procedure for discerning friction work in non-stationary flow is delineated. The research methods encompass both analytical derivation and numerical simulations leveraging Mathcad software. The bespoke Mathcad program crafted for this study can graphically represent multiple flow parameters as functions of time, proving invaluable for comprehending compression wave dynamics and evaluating friction work in diverse non-steady flows. Ultimately, the incorporation of energy equations tailored for non-stationary flows into classical thermodynamics paves the way for a more comprehensive understanding and application of thermodynamics to intricate flow scenarios.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138536144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of radiation absorption and chemical reaction on MHD‐free convective flow through a porous medium past an infinite vertical porous plate in the presence of constant heat flux 恒定热通量下辐射吸收和化学反应对多孔介质中无MHD对流的影响

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2023-08-17 DOI: 10.1002/htj.22936

N. Ahmed, Richa Deb Dowerah

{"title":"Effect of radiation absorption and chemical reaction on MHD‐free convective flow through a porous medium past an infinite vertical porous plate in the presence of constant heat flux","authors":"N. Ahmed, Richa Deb Dowerah","doi":"10.1002/htj.22936","DOIUrl":"https://doi.org/10.1002/htj.22936","url":null,"abstract":"An incompressible, electrically conducting, and viscous fluid flowing steadily and freely across a uniformly porous media that is partially constrained by an infinitely long vertical porous plate is studied in the present article. Additionally, chemical reaction and radiation absorption effects are seen. Here, a magnetic field of uniform strength is applied transversely to the plate, a normal suction velocity is imposed on the fluid, and the heat flux is considered to be constant. The non‐dimensional momentum and energy equations are solved using the method of perturbation. The problem has been analytically resolved, and several parameters, including the Hartmann number, porosity parameter, thermal Grashof number, mass Grashof number, and transport properties like the Sherwood number, skin friction, and plate temperature, are graphically represented. The current study reveals a spike in the radiation absorption effect causes skin friction to drop, but on the other hand, a contrary effect is observed for plate temperature. One of the notable findings of this investigation is that the Sherwood number increases as chemical reaction parameter influence increases.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74154423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study of weakly nonlinear double‐diffusive magnetoconvection under concentration modulation 浓度调制下弱非线性双扩散磁对流的研究

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2023-08-16 DOI: 10.1002/htj.22939

Atul Jakhar, Anand Kumar, Vinod K. Gupta

引用次数: 1

Numerical investigation of the shell configuration effect on the melting of various phase change materials in the presence of porous medium and non‐Newtonian fluid 多孔介质和非牛顿流体存在时壳型对不同相变材料熔化影响的数值研究

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2023-08-14 DOI: 10.1002/htj.22938

Touraj Azarbarzin, K. Javaherdeh

{"title":"Numerical investigation of the shell configuration effect on the melting of various phase change materials in the presence of porous medium and non‐Newtonian fluid","authors":"Touraj Azarbarzin, K. Javaherdeh","doi":"10.1002/htj.22938","DOIUrl":"https://doi.org/10.1002/htj.22938","url":null,"abstract":"By considering the ability of phase change materials (PCMs) in the storage of energy, the melting of four types PCMs including RT22, RT26, RT35, and RT41 in a heat exchanger is examined in this research. The impact of various shell cross‐sectional configurations on the complete melting time of materials, temperature changes, and liquid fraction throughout the melting process are presented. It is assumed that the main heat transfer fluid in the tube is non‐Newtonian and the tube is filled with a porous medium. The enthalpy porosity manner is applied for simulating the process of phase change and the heat natural convection and conduction cases are discussed. On the basis of the obtained results, the decrease in complete melting time is about 20% compared with the absence of a porous medium in the circular cross‐section configuration. The shell configuration has a noticeable impact on the reduction of the required time for melting. In the square cross‐section configuration, RT22 has the lowest melting time, as well as RT41 has the longest melting time in the inverted triangular cross‐section configuration in which the maximum time difference for RT22 is about 77% less. So, the best cross‐section for the shortest complete melting time is square.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74112524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Constructal design of vertical multiscale triangular fins in natural convection 自然对流中垂直多尺度三角翅片结构设计

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2023-08-14 DOI: 10.1002/htj.22935

A. Mustafa, H. S. Hasan, Hadeel Hamid Khlaif

{"title":"Constructal design of vertical multiscale triangular fins in natural convection","authors":"A. Mustafa, H. S. Hasan, Hadeel Hamid Khlaif","doi":"10.1002/htj.22935","DOIUrl":"https://doi.org/10.1002/htj.22935","url":null,"abstract":"Constructal design of vertical multiscale triangular fins in natural convection is investigated in this paper. The design consists of two parts. The first part is for single‐scale triangular fins. The objective in the first design is to reach to the highest heat transfer density from the fins for three fin angles (15°, 30°, and 45°). The single‐scale fins are placed in a horizontal array and considered as isothermal fins. The degrees of freedom are the fin angle, and the fin‐to‐fin spacing. The constraint is the fin height. The second part is for multiscale fins where small fins are placed between the large fins which are optimized in the first part. In the second part, the angles of the large and small scales fins are kept constant at (15°). The optimal fin‐to‐fin spacing which is obtained in the first part is considered a constraint in the second part. The Rayleigh numbers in this design are (Ra = 103, 104, and 105). The two‐dimensional mass, momentum, and energy equations for natural convection are solved with the finite volume method. The results show that there is a benefit of placing the small‐scale fins where the percentage increase in the heat transfer density is (10.22%) at (Ra = 103), and (50.6%) at (Ra = 105) due to existence of the small fins between the large fins.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81487446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Heat transfer characteristics in non‐Newtonian fluid flow due to a naturally permeable curved surface and chemical reaction 非牛顿流体流动中由于自然可渗透曲面和化学反应的传热特性

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2023-08-09 DOI: 10.1002/htj.22934

A. Olkha, Mukesh Kumar

{"title":"Heat transfer characteristics in non‐Newtonian fluid flow due to a naturally permeable curved surface and chemical reaction","authors":"A. Olkha, Mukesh Kumar","doi":"10.1002/htj.22934","DOIUrl":"https://doi.org/10.1002/htj.22934","url":null,"abstract":"In this research endeavor, Casson fluid flow and melting heat transfer due to a curved nonlinearly stretching sheet are investigated. The sheet is naturally permeable and the flow is considered in a porous medium. For flow in a porous medium, a modified Darcy's resistance term for Casson fluid is considered in the momentum equation. In the energy equation, heat transport characteristics, including viscous dissipation, are taken into account. Mass transport is also studied together with the impact of chemical reaction of higher order. The governing nonlinear partial differential equations of flow, heat, and mass transport are reduced to nondimensional ordinary differential equations using adequate similarity transformations and then solved numerically employing the bvp4c technique and Runge–Kutta fourth‐order method on MATLAB. The impacts of numerous occurring parameters on relevant fields (velocity field, temperature field, and concentration field) are depicted and discussed by plotting graphs. We concluded the curvature parameter, reduces the pace of the flow. The impacts of the stretching index, and melting parameter, are also found to reduce flow and temperature field. Furthermore, we noted that the reaction parameter, and its order, exhibit opposite impacts on the concentration field. Moreover, the numerical values of skin‐friction coefficient and Nusselt number calculated employing bvp4c and Runge–Kutta fourth‐order technique are expressed in tabular mode, and these are found in an excellent match. For validation of the results, skin‐friction coefficient values were computed using the Runge–Kutta fourth‐order technique and bvp4c solver, compared with the existing results, and a good agreement was found.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89140798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Forced convective heat transfer for Stokes flow including viscous dissipation in arbitrary corrugated channels 斯托克斯流的强制对流换热，包括任意波纹通道中的粘性耗散

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2023-08-06 DOI: 10.1002/htj.22933

M. Shaimi, R. Khatyr, J. Naciri

{"title":"Forced convective heat transfer for Stokes flow including viscous dissipation in arbitrary corrugated channels","authors":"M. Shaimi, R. Khatyr, J. Naciri","doi":"10.1002/htj.22933","DOIUrl":"https://doi.org/10.1002/htj.22933","url":null,"abstract":"The forced convective heat transfer for Stokes flow, including viscous dissipation in arbitrary corrugated channels, is studied using both an asymptotic method and a numerical solution. The aim is to specify the range of shape parameters for which the validity of the asymptotic approach is ensured, particularly regarding the characteristics of heat transfer. The axial velocity, transversal velocity, pressure, and temperature, for small corrugation's slope compared with unity, are sought as an asymptotic expansion in terms of a parameter that represents the corrugation's slope. The numerical solution is obtained by using ANSYS Fluent solver. Additionally, Python scripting is integrated to automate several parts of the simulations, including the creation of the geometry and a parametric study. Three different types of corrugations are investigated including zigzag, sinusoidal, and arbitrary corrugations defined using a function given by a particular case of the Fourier series. The Nusselt number is calculated to evaluate convective heat transfer. It is found that the asymptotic and numerical solutions for small corrugation's slope, are in good agreement with negligible quantitative differences. However, as the corrugation's slope increases (approaches unity), these quantitative differences increase up to cases where a change in the behavior of the local Nusselt number is observed. The results show that the local Nusselt number decreases in the channel's region with divergent walls due to the decrease in the average velocity. In contrast, it increases in the channel's region with convergent walls due to the increase in the average velocity.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84602270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical investigation of mixed convection of non‐Newtonian fluid in a vented square cavity with fixed baffle 非牛顿流体在带固定挡板的方形通风腔内混合对流的数值研究

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2023-08-02 DOI: 10.1002/htj.22932

Mohammed Abu Ghurban, Khaled Al-Farhany, O. Olayemi

{"title":"Numerical investigation of mixed convection of non‐Newtonian fluid in a vented square cavity with fixed baffle","authors":"Mohammed Abu Ghurban, Khaled Al-Farhany, O. Olayemi","doi":"10.1002/htj.22932","DOIUrl":"https://doi.org/10.1002/htj.22932","url":null,"abstract":"This paper numerically investigates mixed convective heat transfer in a vented square cavity incorporated with a baffle that is subjected to external non‐Newtonian fluids (NNFs). Adiabatic conditions are imposed on the top and bottom walls, while cold temperature conditions are applied to the right and left solid boundaries. Heated NNF enters the cavity through the inlet and goes out through the outlet at three different locations, and it passes on a vertical baffle fixed at the base placed at different lengths. To examine the impact of the inlet and outlet positions, three different shapes of the outlet port located on the right wall and the inlet port on the left bottom wall were investigated. The impacts of Reynolds number (Re) of 100 ≤ Re ≤ 1000, Richardson number (Ri) of 0.1 ≤ Ri ≤ 3, power law index (n) of 0.6 ≤ n ≤ 1.4, length of baffle (Lb) of 0.2 ≤ Lb ≤ 0.6 and the outlet hole positions (S) of on the thermal and flow distributions in the cavity are taken into consideration in this paper. The results demonstrated that the flow's intensity and heat transfer increase with improvement in the Re and n at any baffle length. When the Ri increased from 0.1 to 3, increased by 23.3% at , and 13.8% at . Also, the Ri increment results in the augmentation of the average heat transfer.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89593341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of Oldroyd‐B fluid flow and heat transfer over a stretching sheet with nonlinear radiation and heat source 具有非线性辐射和热源的拉伸板上Oldroyd - B流体流动和传热的研究

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2023-07-31 DOI: 10.1002/htj.22927

M. Goyal, Surbhi Sharma

引用次数: 0

Optimization of port injection of n‐decanol in a PCCI engine using response surface methodology 响应面法优化PCCI发动机正癸醇端口喷射

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2023-07-27 DOI: 10.1002/htj.22930

V. Vinodkumar, A. Karthikeyan, J. Jayaprabakar, G. Senthilkumar, L. Ranganathan

引用次数: 0