Numerical Simulation of Radiation Heat Transfer in a One-Dimensional Graded Index Sphere

2012 ◽  
Vol 430-432 ◽  
pp. 2017-2020
Author(s):  
Lin Zhang ◽  
Shu Yang Wang ◽  
Guo Ling Niu
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Radiative Transfer ◽  
Transfer Problem ◽  
Radiative Transfer Problem ◽  
Fermat Principle ◽  
One Dimensional ◽  
Graded Index ◽  
Element Method

The rays will propagate along a curved path determined by the Fermat principle in medium with inhomogeneous refractive index distribution. To avoid the complicated computation of ray trajectories, a finite element method is extended to solve the radiative transfer problem in a one-dimensional absorbing-emitting semitransparent spherical graded index medium. A problem of radiative transfer inside a semitransparent spherical graded index medium is taken as an example to verify the method. The predicted temperature distributions are determined by the proposed method, and are compared with the results available in references. The results show that finite element method can predict the radiative heat transfer in one-dimensional absorbing-emitting semitransparent spherical graded index medium accurately.

Accelerate Iteration of Least-Squares Finite Element Method for Radiative Heat Transfer in Participating Media With Diffusely Reflecting Walls

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Wei An ◽  
Tong Zhu ◽  
NaiPing Gao
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Boundary Condition ◽  
Finite Element ◽  
Radiative Transfer ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Present Model ◽  
Participating Media ◽  
Element Method

A high reflectivity of walls often leads to prohibitive computation time in the numerical simulation of radiative heat transfer. Such problem becomes very serious in many practical applications, for example, metal processing in high-temperature environment. The present work proposes a modified diffusion synthetic acceleration model to improve the convergence of radiative transfer calculation in participating media with diffusely reflecting boundary. This model adopts the P1 diffusion approximation to rectify the scattering source term of radiative transfer equation and the reflection term of the boundary condition. The corrected formulation for boundary condition is deduced and the algorithm is realized by finite element method. The accuracy of present model is verified by comparing the results with those of Monte Carlo method and finite element method without any accelerative technique. The effects of emissivity of walls and optical thickness on the convergence are investigated. The results indicate that the accuracy of present model is reliable and its accelerative effect is more obvious for the optically thick and scattering dominated media with intensive diffusely reflecting walls.

Heat Transfer Investigation on Center Housing Using Genetic Algorithms and Finite Element Method

2017 ◽  
Author(s):  
Henry Guo ◽  
Farid Ahdad ◽  
Wei Guo ◽  
Huade Yu
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Genetic Algorithms ◽  
Boundary Conditions ◽  
Transfer Problem ◽  
Basic Structure ◽  
Design Stage ◽  
Excessive Heat ◽  
Element Method

Center housing is one of the components of turbocharger which has an undesirable event of excessive heat transfer from turbine side and an excessive heat soak back that lead to oil coking under steady-state conditions and engine shut down conditions. Heat transfer investigation on center housing is necessary to evaluate the designs and prevent oil coking. This paper presents an example of using the genetic algorithms combined to the finite element method to investigate the heat transfer conditions of center housing. First, the basic structure and operation principle of genetic algorithms in heat transfer problem is presented. Then, convection boundary conditions including film heat transfer convection coefficients and bulk temperatures are achieved using genetic algorithms combined with finite element method based on existing test data. Final thermal boundary conditions can be used to predict temperature distribution of center housings before testing in similar applications and which can help re-design the water jacket and oil channel as well in the initial design stage.

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