【摘要】 基于分形理论,利用粉末散体空间的堆积密度、粉末颗粒的密度和孔隙介质的密度,推导出了计算粉末散体空间分形维数的公式;利用等效热阻法建立了粉末散体空间有效热导率的串联分形模型,并给出了考虑热辐射条件的有效热导率的计算公式.通过分形维数和有效热导率计算公式的函数曲线,分析了堆积密度对分形维数以及分形维数、温度对有效热导率的影响,结果表明:粉末散体空间分形维数随堆积密度增大而增大,有效热导率随分形维数增大而减小,随温度升高而增大.更多还原

【Abstract】 Based on the fractal theory,a formula of computing the fractal dimension of the granular powder space is deduced using the accumulated density,powder particles’density and density of the pore media.At the same time,with the method of equivalent resistance,a series fractal model referring to effective themal conductivity of powder dispersion’s space is established.In addition,a formula is given considering the heat radiation.Through the curves of the fractal dimension and effective thermal conductivity’s formula,it is analysed that the packing density has the impact to fractal dimension and the fractal dimension and temperature have influence on the effective thermal conductivity.The results indicate that fractal dimension of granular powder space goes higher with packing density increasing and effective thermal conductivity decreases with fractal dimension and increases with temperature.更多还原