scholarly journals Semianalytical Solution of Transient Heat Transfer for Laminated Structures under Time-Varying Boundary Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xi-Xia Li ◽  
Li Wang ◽  
Chang-Yu Li ◽  
Yi-Yu Wan ◽  
Yu-Chen Qian
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Time Domain ◽  
Transfer Problem ◽  
Heat Transfer Problem ◽  
Transient Heat Transfer ◽  
Maximum Temperature ◽  
Time Varying ◽  
Laminated Structure ◽  
Laminated Structures

In order to solve the transient heat transfer problem of the laminated structure, a semianalytical method based on calculus is adopted. First, the time domain is divided into tiny time segments; the analytical solution of transient heat transfer of laminated structures in the segments is derived by using the method of separation of variables. Then, the semianalytical solution of transient heat transfer in the whole time domain is obtained by circulation. The transient heat transfer of the three-layer structure is analyzed by the semianalytical solution. Three time-varying boundary conditions (a: square wave, b: triangular wave, and c: sinusoidal wave) are applied to the surface of the laminated structure. The influence of some key parameters on the temperature field of the laminated structure is analyzed. It is found that the surface temperature of the laminated structure increases fastest when heated by square wave, and the maximum temperature can reach at 377°C, the temperature rises the most slowly when heated by the triangular wave, and the maximum temperature is 347°C. The novelty of this work is that the analytical method is used to analyze the nonlinear heat transfer problem, which is different from the general numerical method, and this method can be applied to solve the heat transfer problem of general laminated structures.

Transient Heat Transfer of a Hollow Cylinder Subjected to Periodic Boundary Conditions

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Yujia Sun ◽  
Xiaobing Zhang
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Hollow Cylinder ◽  
Periodic Boundary ◽  
Periodic Boundary Conditions ◽  
Transient Heat Transfer ◽  
Maximum Temperature ◽  
Water Cooling ◽  
Chromium Plating ◽  
Inner Surface

The purpose of this paper is to study the transient temperature responses of a hollow cylinder subjected to periodic boundary conditions, which comprises with a short heating period (a few milliseconds) and a relative long cooling period (a few seconds). During the heating process, the inner surface is under complex convection heat transfer condition, which is not so easy to approximate. This paper first calculated the gas temperature history and the convective heat transfer coefficient history between the gas flow and the inner surface and then they were applied to the inner surface as boundary conditions. Finite element analysis was used to solve the transient heat transfer equations of the hollow cylinder. Results show that the inner surface is under strong thermal impact and large temperature gradient occurs in the region adjacent to the inner surface. Sometimes chromium plating and water cooling are used to relief the thermal shock of a tube under such thermal conditions. The effects of these methods are analyzed, and it indicates that the chromium plating can reduce the maximum temperature of the inner surface for the first cycle during periodic heating and the water cooling method can reduce the growth trend of the maximum temperature for sustained conditions. We also investigate the effects of different parameters on the maximum temperature of the inner surface, like chromium thickness, water velocity, channel diameter, and number of cooling channels.

Meshless Local Petrov-Galerkin Method for Heat Transfer Analysis

2013 ◽  
Author(s):  
Singiresu S. Rao
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Boundary Conditions ◽  
Transfer Coefficient ◽  
Transfer Problem ◽  
Radiation Heat Transfer ◽  
Heat Transfer Problem ◽  
Radiation Heat ◽  
Mlpg Method ◽  
Transfer Problems

A meshless local Petrov-Galerkin (MLPG) method is proposed to obtain the numerical solution of nonlinear heat transfer problems. The moving least squares scheme is generalized, to construct the field variable and its derivative continuously over the entire domain. The essential boundary conditions are enforced by the direct scheme. The radiation heat transfer coefficient is defined, and the nonlinear boundary value problem is solved as a sequence of linear problems each time updating the radiation heat transfer coefficient. The matrix formulation is used to drive the equations for a 3 dimensional nonlinear coupled radiation heat transfer problem. By using the MPLG method, along with the linearization of the nonlinear radiation problem, a new numerical approach is proposed to find the solution of the coupled heat transfer problem. A numerical study of the dimensionless size parameters for the quadrature and support domains is conducted to find the most appropriate values to ensure convergence of the nodal temperatures to the correct values quickly. Numerical examples are presented to illustrate the applicability and effectiveness of the proposed methodology for the solution of heat transfer problems involving radiation with different types of boundary conditions. In each case, the results obtained using the MLPG method are compared with those given by the FEM method for validation of the results.

A Coupled Computational Framework for the Transient Heat Transfer in a Circular Pipe Heated Internally With Expanding Heat Sources

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Chaobin Hu ◽  
Xiaobing Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Energetic Materials ◽  
Transfer Problem ◽  
Lumped Parameter Model ◽  
Heat Transfer Problem ◽  
Transient Heat Transfer ◽  
Combustion Model ◽  
Heat Sources ◽  
Computational Framework

Abstract In the present work, a transient heat transfer problem induced by internal combustion of energetic materials was studied. Most of previous studies utilized a lumped-parameter model to predict the parameter distributions of the hot combustion products, which determine the boundary conditions for the transient heat transfer problem. Moreover, the heat exchange between the solids and the fluids was ignored in the combustion model. In order to improve the modeling accuracy, a one-dimensional (1D) two-phase flow model was utilized to predict the fluid fields and the heat exchange was coupled into the combustion model. Based on the commercial software abaqus, the transient heat transfer in the combustion chamber was studied using a finite element method. The meshes near the inner surface were refined to capture the high temperature gradients along the radial direction of the barrel. Results indicate that the coupled model is capable of solving the transient heat transfer problems heated by distributed moving heat sources. The coupled computational framework provides foundations for the study of local wear and erosion of solids in extreme working conditions.

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