多孔介质等效导热系数研究进展

A Review of Research on the Equivalent Thermal Conductivity of Porous Media

多孔介质凭其轻质、隔热性能好的优点,在高超声速飞行器热防护系统中具有重要的应用价值,通常可以借助等效导热系数来评价其传热性能.多孔介质内部微观结构存在复杂性、随机性,对多孔介质等效导热系数的研究通常包括实验研究、理论分析和数值模拟三个方面.文中从实验研究开始综述,由于材料的结构和传热的方式不同,研究多孔介质等效导热系数的实验也不同,但都是基于傅立叶导热定律来研究;随后介绍多孔介质的理论分析模型,多孔介质等效导热系数的研究大多基于五种基本模型,与实验或数值模拟获得的经验参数进行结合来适应不同类型的多孔介质;然后介绍了现代数值模拟在多孔介质等效导热系数预测中的应用,这种方法虽然比较复杂,但是数值模拟的结果与实验结果最为接近;最后,对多孔介质等效导热系数研究进行展望.

Porous media has significant application values in the thermal protection system of the hypersonic vehicle due to its advantages of lightweight and good thermal insulation performances.The heat transfer performance of porous materials could be evaluated by the equivalent thermal conductivity.Due to the complexity and randomness of the internal microstructure of porous media,the study of the equivalent thermal conductivity of porous media usually includes experimental research,theoretical analysis,and numerical simulation.This review began with different experiments based on Fourier’s law for different material structures and heat transfer modes;Based on five basic models,there are many theories researching equivalent thermal conductivity of porous materials,which could be combined with experimental and numerical simulation to get experience parameters to adapt different porous materials;Next,we introduced the adhibition of predicting the equivalent thermal conductivity of porous media by numerical simulation,which is close to experiment although the computation is complicated.Finally,future work on porous media is suggested from the view of inverse aspect.