激波与单/双球模型相互作用有效阻力的实验研究

Experimental Investigation of Effective Drag on a Single or a Double Spherical Model by Shock Loading

利用水平激波管、高频应变传感器和高速数据采集系统等仪器设备,对激波加载单、双球模型时的有效阻力进行直接测量。实验结果表明,对于单球模型,有效阻力系数随激波马赫数的增大而减小;对于双球模型,有效阻力系数随无量纲间距的增大,先增大后减小并趋于稳定;颗粒载荷比足够大时,须考虑激波和尾迹涡相互干涉影响,采用颗粒群阻力系数模型,阻力系数开始趋于稳定值的无量纲间距可以作为阻力系数模型选择的划分标准。

In this study,the effective drags acted on single and double spherical models were directly measured during their interaction with a planar shock wave.The experiments were conducted by using a measuring system mainly consists of a horizontal shock tube with the inner diameter of 200 mm,a high-frequency strain transducer and a high-speed data acquisition system.The result shows that in single-spherical-model cases,effective drag coefficient decreases as shock Mach number increases,and in double-spherical-model cases,effective drag coefficient increases first,and then decreases,finally trends to be stable.It can be summarized that it is necessary to consider the influence of the interferences of shock structures and wake vortexes attributed to different neighbouring particles when particle loading ratio is high enough,in other words,a particle group drag coefficient model,rather than a single particle one should be employed for a gas-solid two-phase flow modeling,furthermore,that the dimensionless interval distance value,corresponding to a point,from which the effective drag coefficient begins to be almost unchangeable,could be regarded as a criteria to choose a proper drag coefficient model.