旋射流气波制冷机实验研究及数值模拟

针对目前气波制冷机的接受管开口端存在较多熵增因素从而制约制冷效率进一步提高的缺点,借鉴了透平膨胀机制冷机理,将现有气体分配器改型,融入旋射流作功机理,加大出流偏角,使射向接受管气体射流反冲膨胀作功,减少熵增、降低入射气体的射流速度,从而有效改善接受管入口端射流气体的流动状况,达到降低工质速度、减小总焓及提高等熵效率的目的.利用Godunov格式建立了管内非定常流动与管壁传热数学模型,对接受管内激波的流动进行了数值模拟,计算结果与实验测量值趋势相同,可为气波制冷机的改造、设计及优化提供参考.

Experimental study and simulation of swirling jet gas wave refrigerator

There are some factors that cause entropy increase at the opening-end of receiving tube of the existing gas wave refrigerator(GWR),and the increase of entropy blocks the efficiency improving.Using the theory of turbing basing inflation refrigerator for reference and combining the mechanism of swirling jet working,gas distributor was remodeled and the outlet drift angle was enlarged, which makes the injection gas in receiving tube reaction-propelled inflation work,cuts down the entropy increase and reduces the flow rate of injection gas. Thus the flow state of the injection gas is improved at the opening-end of receiving tube,and the goal of reducing the velocity of work substance,decreasing gross enthalpy,and improving isentropic efficiency are achieved.A mathematic model is proposed to study the process of unsteady flow in the tube and the heat transfer across the tube wall using Godunov format.The numerical simulations of the flow state of shock wave in receiving tube matches the measured values well.The results of the study can be used for the reforming,designing and optimizing of wave machines.