基于斐波那契数积分计算非等径颗粒视角系数

Fibonacci integration for evaluating view factors coefficient of non-equal-diameter particles

热辐射是颗粒间热量传递的基本方式之一,视角系数计算的效率和精度是颗粒热辐射数值模拟中的主要难点。本文采用斐波那契数列对非等径颗粒表面进行离散,在此基础上计算视角系数,并且对z方向的积分使用非均匀变换以提高计算精度。结果表明,在具有不同球体数的粉末床中,用该方法计算的视角系数的相对误差为5%,与传统的蒙特卡洛方法相比,计算效率提升约30%。

Thermal radiation is one of the basic forms of heat transfer between particles.Computing efficiency and accuracy are the difficulties to calculate the view factors when simulating thermal radiation.In this paper,the Fibonacci number is used to discretize the surface of non-equal-diameter particles,and the view factors are calculated based on it.Subsequently,the non-uniform transformation in the Z direction is adopted to improve computational accuracy.It is indicated that a relative error of 5%for the view factor in a packed bed containing different numbers of spheres calculated is obtained by the proposed method.Compared with the traditional Monte Carlo method,the computational efficiency is improved by about 30%.