激波管内压力脉冲演化特性及模拟空爆冲击波的方法研究

The evolution characteristics of pressure pulse in the shock tube are studied to generate a shock wave similar to the air explosion shock wave in the tube. The process of forming a shock wave similar to air explosion shock wave in shock tube driven by high pressure gas is analyzed through the experimental study and numerical simulation of pressure pulse characteristics in shock tube, and the relationship between shock wave characteristics and shock tube parameters is established. The results show that the shock wave generated in the shock tube is a plane wave. When the length of the low pressure section of shock tube is long enough, the reflected rarefaction wave in the low pressure section can catch up with the right shock wave front, and form a shock wave similar to the air explosion shock wave at the overtaking position. The decrease in the driving pressure and length of the high pressure section makes the rarefaction wave easier catch up with the shock wave. As the pressure in the low pressure section increases, the velocity of the shock wave decreases, and the reflected rarefaction wave catches up with the shock wave faster. At the same time, the shock wave travels shorter in the low pressure section, and the positive pressure duration of the shock wave pressure is shorter. The characteristic parameters such as peak overpressure and positive pressure duration of shock wave are related to the driving pressure and length of the low pressure section of the shock tube. Combined with dimensional analysis, the minimum length of low pressure section required to form simulated air explosion shock wave is established, and the relationship among the characteristic parameters such as peak overpressure and positive pressure duration of shock wave and the parameters such as pressure and length in shock tube is established, which provides basic theory and data support for the design of simulated air explosion shock tube.