Errors in one-dimensional fin optimization problem for convective heat transfer

A new efficient and accurate procedure for solving heat condution problems

An analytical study of the optimum dimensions of rectangular fins and cylindrical pin fins

In this paper, a new technique of differential quadature method called the upwind difference - differential quadature method (UDDQM) for solving two-dimensional heat transfer (convection-diffusion) problems is proposed. Also, investigated the effects of physical quantities on behavior of flow problems, and combined effects of upwind difference mechanism together with differential quadrature method to modified the numerical solutions of heat transfer problems are presented. To validate our proposed UDDQM, two convection-diffusion problems ((i) Steady-state incompressible flow problem has exact solution and (ii) Natural convection motion of the incompressible fluid flow problem hasn't exact solution) are solving numerically. Graphical results on the effects of parameter variation on velocity, temperature, Peclet number, Grashof number, and Prandtl number are presented and discussed. Numerical experiments are conducted to test its accuracy and convergence and compare it with the standard DQM and other numerical methods that are available in literature. The numerical results show the efficiency of the proposed method to handle the problems, and it is more accurate and convergent than other methods.

The solution of the conjugate problem of convective-conductive heat transfer in the channels of power plants is presented. The problem of convective heat transfer in the gas phase is solved by the integral theory of heat transfer. A one-dimensional problem of conductive heat transfer in the material of the wall is solved by the finite-difference method. Relative laws of heat and mass transfer and friction are obtained by numerical integration with respect to the boundary-layer thickness. The effect of the material and geometry of the wall on the level of problem “conjugation” is studied.

Numerical evaluation of the latent heat thermal energy storage performance enhancement by installing longitudinal fins

Performance and optimum design analysis of longitudinal and pin fins with simultaneous heat and mass transfer: Unified and comparative investigations

Chapter XVI - Longitudinal Fins and Twisted Tapes within Ducts

Review of utilization of extended surfaces in heat transfer problems

This paper examines the augmentation of heat and mass transfer due to dual clearances on cylindrical pin fins, relative to a channel between parallel plates, in mini/microchannel reactors at low Reynolds numbers. In this work, diffusion limitations to heat and mass transfer in smooth-walled mini/microchannel reactors were minimized by the implementation of microcylinder pin fins with dual clearances that, (1) promote the production of instabilities in the wakes that enhance mixing and (2) reduce the viscosity dominated regions at pin-wall interfaces. A smooth catalyst coating is assumed on all exposed surfaces of the microchannel interior walls and pin fins. Due to the analogy of heat and mass transfer, augmentation of the Nusselt number is equivalent to the augmentation of the Sherwood number. Heat transfer augmentation is investigated in air (Pr = 0.705) at dual clearances ranging from 0 to 0.4 of the channel height and Reynolds numbers from 10 to 600. The pin fins and the clearance augmented the heat transfer coefficient by a factor of 4.0. The combination of the augmentation of the heat transfer coefficient and the increase in the surface area, by the clearances, results in an increase in the conductance over a plane channel, by a factor of 7.1. The results are extendable to overcoming laminar diffusion with laminar periodic wakes of fuel vapors such as methanol vapor in air where Scfuel ∼ Prair. For turbulent wakes impinging upon downstream pins, the results can be extended to fuel vapors with (Scfuel)turb ∼ (Prair)turb. A large eddy simulation (LES) approach was used in this study.

A general procedure for infrared thermography heat transfer measurements in hypersonic wind tunnels

Numerical investigation and optimization of an asymmetric elliptical-cylindrical pin fin heat sink

In this work, the photovoltaic panel performance has been investigated theoretically and experimentally where using an array of pin fins as a cooling system. Trying to satisfy the ideal operation conditions of the solar panel, heat sink was fixated on the back of the PV panel to use as a passive technique. An Analytical thermal model based on the steady state and one dimension analysis condition was built to transfer the excess heat from PV panel with the heat sink existing to predict the operation temperature of PV panel. Theoretical results were compared with experimental results of solar panels cooled by heat sink, in order to validate the suggested thermal model. Also, the effect of the solar cells temperature on the panel performance has been studied experimentally. The results displays that using pin fins array as a cooling technique led to drop in the average panel's temperature nearly 5.9°C and an enhancement of the average output power nearly 13.5%.

Analytical methods exist to solve the problems of hydromechanics and heat transfer, but it is not possible to obtain the solution to some inhomogeneous and nonlinear problems of hydromechanics and heat transfer by analytical methods. The solution to such problems is carried out using numerical methods. Currently, there are many textbooks and monographs on numerical methods for solving problems of hydromechanics, thermal conductivity, heat and mass transfer, and others. The article presents the results of a numerical study of the flow structure in the flow around a flat plate. The calculations are based on the numerical solution of a system of nonstationary equations using a two-fluid turbulence model. For the numerical solution of these problems, schemes of the second and fourth order of accuracy were applied. The control volume method was used for the difference approximation of the initial equations, and the relationship between velocities and pressure was found using the SIMPLE procedure. To confirm the correctness of the numerical results, comparisons were made with each other and experimental data.

Orthotropic thermal conductivity effect on cylindrical pin fin heat transfer

Eigenfunction-based solution for one-dimensional solid-liquid phase change heat transfer problems with advection