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analysis of influence of heat exchangerfouling on heat transfer performancebased on thermal fluid coupling

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排灌机械工程学报 2023年第7期41卷 695-700页

作者： HUANG Si MURAD Tariq NIU Qifeng LIN Guangtang CHEN Jianxun School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhouGuangdong 510641China Guangdong Institute of Special Equipment Inspection and Research Zhuhai Branch ZhuhaiGuangdong 519002China

A study on heat transfer performance by thermal fluid coupling simulation for the fouling in a shell-tube heat exchanger used in engineering was presented. The coupling simulation was performed in a fluid and solid domains under three different fouling conditions: fouling inside the tube, fouling outside the tube, and fouling inside the shell. The flow field, temperature, and pressure distributions in the heat exchanger were solved numerically to analyze the heat transfer performance parameters, such as thermal resistance. It is found that the pressure drop of the heat exchanger and the thermal resistance of the tube wall increase by nearly 30% and 20%, respectively, when the relative fouling thickness reaches 10%. The fouling inside the tube has more impact on the heat transfer performance of the heat exchanger, and the fouling inside the shell has less impact.

关键词： shell-tube heat exchanger thermal fluid coupling fouling thermal resistance heat transfer analysis

Experimental and numerical analysis of the hydraulic and thermal performances of the gradually-varied porous volumetric solar receiver

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Science China(Technological Sciences) 2020年第7期63卷 1224-1234页

作者： DU Shen LI ZengYao HE YaLing LI Dong XIE XiangQian GAO Yang Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi'an Jiaotong UniversityXi'an 710049China Science and Technology on Space Physics Laboratory China Academy of Launch Vehicle TechnologyBeijing 100076China

A gradually-varied porous structure is designed to increase the thermal performance of the porous volumetric solar *** on the replica method and multilayer recoating technique, the silicon carbide porous ceramic with linear-changed geometrical parameters is fabricated. The performances of the uniform and gradually-varied porous volumetric solar receivers are studied by both experiment and numerical simulation. An optimization method combining genetic algorithm and computational fluid dynamics analysis is applied to determine the optimum porosity distribution. The results present that porous volumetric solar receiver with linear-changed geometrical parameters exhibits better thermal performance than the uniform porous volumetric solar receivers, especially when the thickness of the receiver is small. Larger porosity in the front is beneficial for increasing the solar radiation penetration depth, which limits the reflectance and thermal radiative losses. Smaller porosity in the rear traps more solar radiation and increases the convective heat transfer. When the receiver’s thickness is larger, the performance of the gradually-varied volumetric solar receiver is nearly identical to that of the uniform receiver with largest porosity. The double-layer configuration is found to be the optimized structure of the gradually-varied porous volumetric solar receiver. The thermal efficiency could be further improved using genetic algorithm with an 11 K increase of the outlet temperature.

关键词： gradually-varied porous volumetric solar receiver replica method local thermal non-equilibrium heat transfer analysis optimization design

heat transfer and parametric studies of an encapsulated phase change material based cool thermal energy storage system

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第11期7卷 1886-1895页

作者： CHERALATHAN M. VELRAJ R. RENGANARAYANAN S. School of Mechanical Engineering S.R.M. Engineering College SRM University Kattankulathur Chennai 603203 Tamilnadu India Institute for Energy Studies Anna University Chennai 600025 India

This work investigates the transient behaviour of a phase change material based cool thermal energy storage (CTES) system comprised of a cylindrical storage tank filled with encapsulated phase change materials (PCMs) in spherical container integrated with an ethylene glycol chiller plant. A simulation program was developed to evaluate the temperature histories of the heat transfer fluid (HTF) and the phase change material at any axial location during the charging period. The results of the model were validated by comparison with experimental results of temperature profiles of HTF and PCM. The model was also used to investigate the effect of porosity, Stanton number, Stefan number and Peclet number on CTES system performance. The results showed that increase in porosity contributes to a higher rate of energy storage. However, for a given geometry and heat transfer coefficient, the mass of PCM charged in the unit decreases as the increase in porosity. The St number as well as the Ste number is also influential in the performance of the unit. The model is a convenient and more suitable method to determine the heat transfer characteristics of CTES system. The results reported are much useful for designing CTES system.

关键词： Cool thermal energy storage (CTES) Energy storage Freezing Phase change materials (PCMs) heat transfer analysis Refrigeration

Effects of heat transfer on the peristaltic MHD flow of a Bingham fluid through a porous medium in a channel

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International Journal of Biomathematics 2014年第6期7卷 1-20页

作者： V. P. Rathod D. Laxmi Department of Mathematics CNCS Harmaya University Ethiopia Department of Studies and Research in Mathematics Gulbarga University Gulbarga 585106 Karnataka India

In this paper, we study the effects of heat transfer on the peristaltic magneto- hydrodynamic （MHD） flow of a Bingham fluid through a porous medium in a channel. Long wavelength approximation （that is, the wavelength of the peristaltic wave is large in comparison with the radius of the channel） and low Reynolds number are used to linearize the governing equations. The velocity field for the model of interest is solved by Adomian decomposition method. The expressions for pressure rise, flow rate and frictional force are obtained. The effect of magnetic field, Darcy number, yield stress, amplitude ratio and the temperature on the axial pressure gradient, pumping charac- teristics and frictional force are discussed through graphs.

关键词： Bingham fluid yield stress peristaltic flow magneto-hydrodynamic fluid heat transfer analysis Adomian decomposition method.

AN ADAPTIVE ALGORITHM OF PRECISE INTEGRATION FOR TRANSIENT analysis

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Acta Mechanica Solida Sinica 2001年第3期14卷 215-224页

作者： Zhang Hongwu Chen Biaosong gu Yuanxian Dalian Univ Technol Dept Mech Engn State Key Lab Struct Anal Ind Equipment Dalian 116024 Peoples R China

This paper presents an improved precise integration algorithm fortransient analysis of heat transfer and some other problems. Theoriginal precise integration method is improved by means of the inve-rse accuracy analysis so that the parameter N, which has been takenas a constant and an independent pa- rameter without consideration ofthe problems in the original method, can be generated automaticallyby the algorithm itself.

关键词： heat transfer analysis precise integration method inverse accuracyanalysis

Phase change analysis of an underwater glider propelled by the ocean's thermal energy

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Journal of Marine Science and Application 2007年第4期6卷 37-43页

作者： KONG Qiao-ling MA Jie State Key Laboratory of Ocean Engineering Shanghai Jiaotong University Shanghai 200030 China

The phase change characteristic of the power source of an underwater glider propelled by the ocean＇s thermal energy is the key factor in glider attitude control. A numerical model has been established based on the enthalpy method to analyze the phase change heat transfer process under convective boundary conditions. Phase change is not an isothermal process, but one that occurs at a range of temperature. The total melting time of the material is very sensitive to the surrounding temperature. When the temperature of the surroundings decreases 8 degrees, the total melting time increases 1.8 times. But variations in surrounding temperature have little effect on the initial temperature of phase change, and the slope of the temperature time history curve remains the same. However, the temperature at which phase change is completed decreases significantly. Our research shows that the phase change process is also affected by container size, boundary conditions, and the power source＇s cross sectional area. Materials stored in 3 cylindrical containers with a diameter of 38ram needed the shortest phase change time. Our conclusions should be helpful in effective design of underwater glider power systems.

关键词： phase change heat transfer analysis ocean thermal energy underwater glider

一种耦合SPH方法求解涉及流固耦合的热传导问题

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Acta Mechanica Sinica 2023年第2期39卷 71-85页

作者：唐晓静张驰 Oskar Haidn 胡湘渝 TUM School of Engineering and Design Technical University of MunichGarching85748Germany

由于流体动力学、固体运动学和传热的共存,热-流体-结构相互作用(TFSI)问题通常在基于网格的方法中造成数值复杂性.本文介绍了一种在材料界面处具有强耦合方案的耦合光滑粒子流体动力学(SPH)求解器来研究TFSI问题.本方法耦合了一些有效... 详细信息

由于流体动力学、固体运动学和传热的共存,热-流体-结构相互作用(TFSI)问题通常在基于网格的方法中造成数值复杂性.本文介绍了一种在材料界面处具有强耦合方案的耦合光滑粒子流体动力学(SPH)求解器来研究TFSI问题.本方法耦合了一些有效的技术,包括固体动力学拉格朗日公式中的核修改和流体结构相互作用(FSI)的多时间步进,以提高计算精度和效率;还应用基于位置的Verlet积分格式来实现严格的动量守恒;两级龙格-库塔积分方案用于求解热扩散方程.本文执行了两个模拟案例来测试本方法,包括微通道中传热的数值示例和FSI案例,在加热通道流中使用不同的涡流发生器研究和量化传热性能.本SPH-TFSI求解器获得的详细热量和涡流信息表明,FSI通过涡流与边界层内的流体相互作用来加强传热.这项研究证明了无网格SPH方法在涉及具有大结构变形的涡流发生器的工业传热应用中的多功能性和潜力.

关键词： Smoothed particle hydrodynamics heat transfer analysis Thermal-fuid-structure interaction Vortex generator

Application of First-Order Differential Equation to heat Convection in Fluid

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Journal of Applied Mathematics and Physics 2020年第8期8卷 1456-1462页

作者： Zahidullah Rehan Department Mathematics and Physics Sayed Jamaluddin Afghani University Asadabad Afghanistan

Differential equation is very important in science and engineering, because it required the description of some measurable quantities (position, temperature, population, concentration, electrical current, etc.) in mathematical form of ordinary differential equations (ODEs). In this research, we determine heat transferred by convection in fluid problems by first-order ordinary differential equations. So in this research work first we discuss the solution of ordinary homogeneous and non-homogeneous differential equation and then apply the solution of first-order ODEs to heat transferring particularly in heat convection in fluid.

关键词： Differential Equation heat transfer analysis heat Convection in Fluid Newton Cooling Law

Finite Element analysis for Temperature Compensation of ITO Conductive Film System

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Journal of Mechanics Engineering and Automation 2021年第4期11卷 91-96页

作者： Wen-Chang Tsao Wen-Ning Chuang Min-Wei Hung National Applied Research Laboratories Taiwan Instrument Research Institute20 R&D Road VIHsinchu Science ParkHsinchu 300092Taiwan

Indium tin oxide(ITO)heating film is primarily used as the defogging component of an instrument observation ***,a constant current is used to heat the *** the feedback of the temperature sensing component,the output current is adjusted to achieve a set ***,the temperature of the heating film is nonuniformly distributed,and determining the correct output current is *** study adopted finite element heat transfer analysis to determine a heating method(such as heat power and heat flux)for an ITO conductive heating film *** results of the analysis may serve as a reference for temperature compensation in ITO conductive heating films.

关键词： ITO film heater heat transfer analysis heat power,heat flux.