非均匀多孔介质中导热过程

采用控制容积法和界面调和平均导热系数以及图形处理方法,对典型非均匀多孔介质Sierpinski地毯中的导热过程进行分析与模拟计算.结果表明:实际多孔介质中温度与热流分布是不均匀和不连续的,内部结构是影响温度分布和热量传递的主要因素,其影响程度与骨架和孔隙的导热系数、孔隙的大小和分布有关;温度梯度在孔隙中明显变大与孔隙处导热系数很小相对应;热流在孔隙和骨架交界处的局部区域中明显变大,尤其是在方形孔隙的角部出现热流峰值,这与温度发生突变的位置点相对应.研究结果可以推广到更为复杂的非均匀多孔介质的场合,可以进一步认识非均匀多孔介质中的导热规律,为工程计算提供更精确的计算方法.

Heat conduction process in non-uniform porous media

Heat conduction in a kind of typical non-uniform porous media, Sierpinski carpet, was analyzed and simulated, in which finite volume method and interface harmonic average thermal conductivity were adopted. The calculated results show that the distribution of temperature and heat fluxes in real porous media are non-uniform and discontinuous. Inner structure acts as a main influencing factor to heat conduction process. The influencing degree is consequent on the thermal conductivities of both matrix and pore. Moreover, the size and distribution of pores are also important factors. Corresponding to the smaller thermal conductivity, temperature gradient in pores obviously increases. Heat flux increases sharply in the interface of matrix and pore, especially in the comer of pore appears a peak value, which corresponds to the break point of temperature and centralizing area of thermal stress. The conclusions of this paper can be extended to more complicated situations of non-uniform porous media, thus the principles of heat conduction can be further discovered, which provides more precise methods for engineering calculation.