The field characteristics of coherent jet and conventional supersonic jet was studied by numerical simulation and experiment under different shrouding gas parameter conditions. The results show that the temperature and pressure of the nozzle exit is affected by shrouding gas and it leads to velocity and temperature fluctuations of the supersonic jet. The low-density and high-speed environment produced by high temperature and high flow of the shrouding gas protects supersonic jet, and reduces radial expansion and axial velocity attenuation rate of the jet. The higher the temperature and flow are, the longer the velocity and temperature core length of the jet are. Compared with conventional supersonic jet, the distributions of half-jet width and vorticity are changed by shrouding gas. With the high temperature and flow of the shrouding gas, the turbulence intensity of the jet maintains at low level over a long distance.%针对不同伴随流参数条件下的集束射流和普通超音速射流流场特性进行数值模拟和试验研究.研究结果表明:伴随流气体影响喷管出口温度和压力,导致超音速主射流速度和温度出现重复波动;高温、大流量伴随流气体形成的低密度和高速环境可保护超音速射流,降低射流径向的扩展率和轴向速度的衰减速率;伴随流气体温度越高,流量越大,射流速度和温度核心段长度越长.与普通超音速射流相比,伴随流气体改变射流半速度宽度和涡量的分布;伴随流温度越高,流量越大,射流在更长的距离内保持较低的湍流强度.
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