【摘要】 本文运用工程方法设计了喷气Z箍缩装置的超声速喷管,通过数值求解Navier Stokes方程模拟了气流从储气室到喷管出口的非定常流动过程,最后用DSMC方法计算了喷管出口气体向真空中的膨胀,得到了喷气负载的气流位形和质量线密度。计算结果表明,除了储气室的压力、喷管的喉道和出口尺寸等因素外,负载的特性参数较强地依赖于阀门开启和关闭时间、阀门开启的速度、开启的口径大小以及阀门后真空管道的几何形状。采用定常流动模型比非定常流动模型预测的负载质量线密度大10倍左右,而后者与实验结果较为一致。更多还原

【Abstract】 In this paper, a simple engineering method is employed to design supersonic nozzles used in a gas puff Z-Pinch device. The internal unsteady gas　flow from a plenum chamber to the supersonic nozzle exit was simulated by solving the Navier-Stockes(NS) equations. In order to obtain the line mass density and radial density profiles of the supersonic gas shell injected out of the annular nozzle exit, the direct simulation Monte Carlo(DSMC) method was employed to simulate the gas explosion processes. Results from calculation showed that besides the pressure level of the plenum chamber and charac- teristic size of the nozzle, the specific parameters of the gas puff were strongly dependent on the action of the valve and the geometric shapes of the vaccum channel behind it. We had made a calculation on the steady state flow from such a nozzle at a plenum pressure of 0.5 atm and found that the line mass density predicted by the steady state model was about 10 times higher than that using unsteady state model, while the later results were in agreement well with experimental results.更多还原