中文摘要：

为了探索高温高压周向均布多股贴壁燃气射流在受限空间内液体工质中的扩展特性,设计了贴壁燃气射流在圆柱形充液室内扩展的实验装置。用数字高速录像系统记录多股贴壁燃气射流在充液室中的扩展过程,处理拍摄记录的射流扩展序列图,获得了不同时刻多股射流形态头部的平均轴向位移。从射流扩展序列图可以发现由Kelvin-Helmholtz不稳定性引起的表面不规则一直存在于整个射流扩展过程。通过改变喷孔个数和破膜喷射压力,对比分析了不同工况下多股贴壁燃气射流的扩展特性。结果表明： 喷孔个数增加,相同时刻射流轴向扩展位移变小,t=5 ms时刻,从四孔增加到六孔,其轴向扩展位移减少了8.3%,从六孔增加到八孔,减少了3.1%; 随着破膜喷射压力增大,射流轴向扩展速度更快,射流轴向扩展到达充液室顶部的时间变短,t=5 ms时刻,燃气破膜压力从12 MPa增加到20 MPa,射流轴向扩展速度增加了20.1%,从20 MPa增加到28 MPa,增加了19.9%。

英文摘要：

To explore the expansion characteristics of multiple wall combustion-gas jets which uniformly distributed along the circumferential direction under high temperature and high pressure in confined liquid working medium, the combustion gas generator and cylindrical filling liquid chamber were designed. The expansion processes of multiple wall jets were recorded by high-speed digital photographic system. The average axial displacements of multiple wall jets at different time were achieved by disposing the expansion sequence diagrams. It shows that the irregular interface induced by the Kelvin-Helmholtz instability exists in the entire jets expansion process. The effects of the number of orifices and the blasting injection pressure on expansion characteristics of multiple wall jets are discussed. The experimental results indicate that, as the number of orifices increase from four to eight, the axial expansion displacements of multiple jets decrease, at t=5 ms, the number of orifices increase from four to six, the axial expansion displacements decrease 8.3 percent, and it decrease 3.1 percent when the number of orifices increase from six to eight. The larger the blasting injection pressure, the greater the axial expansion velocity, the earlier jets get to the top of liquid filling chamber, at t=5 ms, the blasting injection pressure increase from 12 MPa to 20 MPa, the axial expansion velocity increase 20.1 percent, and it increase 19.9 percent when the blasting injection pressure increase from 20 MPa to 28 MPa.