喷管不足膨胀冲击喷流的数值研究

Numerical Study on Nozzle Underexpanded Impinging Jet Flows and Its Complex Wave Fields

针对喷管不足膨胀冲击喷流具有复杂波系结构的特点，应用高分辨率的ＴＶＤ格式建立了求解轴对称Ｎ－Ｓ方程的数值研究方法．对一定压比的冲击喷流在不同的喷管和平板间距下的流场进行了数值计算，得到了冲击喷流的复杂波系．对冲击喷流中盘形激波的形状、冲击平板的压力分布以及二者的关系进行了研究分析，揭示了冲击喷流产生分离泡的机理．

Complex wave structure of nozzle underexpanded impinging jet flows on a flat plate is studied by a numerical solver of the axisymmetric Navier Stokes equations using a high resolution TVD scheme. Results are obtained for different distances between the nozzle and the flat plate under certain pressure ratios. Analyzed are the shape of the disk shock wave, pressure distribution of the impinging flow and their relations. Insights are gained with the bubble formation mechanism in the impinging jet flow field.