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针对空间绿色单组元发动机热启动工况,搭建了蓄换热实验装置,研究了泡沫镍的厚度、孔密度、体密度等参数对其与流动介质瞬时换热能力的影响。研究表明,泡沫镍的瞬时换热能力随厚度的增加而增强;在孔密度较小时(20~70PPI),比表面积是影响泡沫镍的瞬时换热能力的关键因素,瞬时换热能力随孔密度和体密度的增加而增强;在孔密度较高时(100PPI),流阻成为影响泡沫镍的瞬时换热能力的主要因素,泡沫镍的瞬时换热能力大幅增强,但随体密度的增加变化不明显。搭建了强制对流条件下泡沫材料流阻实验装置,测量和比较了泡沫镍与催化剂的流阻,发现泡沫镍的流阻随孔密度和体密度的增加而增大,所有泡沫镍的流阻均小于催化剂的流阻。从实际应用角度看,应综合考虑蓄换热实验、点火实验结果和对泡沫金属的力学性能要求等多项因素来选择泡沫金属的参数。
Aiming at the green start-up mode of green single component engine, a heat storage and transfer experiment device was set up to study the influence of foam nickel thickness, hole density and bulk density on its instantaneous heat transfer capacity. The results show that the instantaneous heat transfer capacity of nickel foam increases with the increase of the thickness. When the pore density is small (20 ~ 70PPI), the specific surface area is the key factor that affects the instantaneous heat transfer capacity of nickel foam. (100PPI), the flow resistance is the main factor that affects the instantaneous heat transfer capacity of nickel foam. The instantaneous heat transfer capacity of nickel foam greatly increases, but with the increase of the bulk density, Not obvious. The flow resistance of foamed material under forced convection was set up. The flow resistance of foamed nickel was measured and compared. It was found that the flow resistance of foamed nickel increased with the increase of cell density and bulk density. The flow resistance of all foamed nickel Less than the flow resistance of the catalyst. From a practical application point of view, the parameters of foam metal should be selected considering a number of factors, such as the heat transfer experiment, the ignition experiment results and the mechanical properties of the foam metal.