等离子射流近场特性的数值模拟

摘要

The plasma j et ignition technology has wide applications in aerospace,weapons and civilian industry.To explore the ignition properties of the plasma j et,we have conducted numerical simulation to study the characteristics of the near field of the transient plasma j et propagation in air,and have obtained the distribution properties of pressure,velocity,temperature and the evolution characteristics of the plasma-air interface.The results indicate that,as the plasma j et propagates,the Mach disk is formed gradually at the near field,and this is accompanied by the phenomenon that the plasma j et ramifies and converges.The parameters of the normal shock upstream do not vary with time,while the parameters downstream do.The calculated displacement of the front of the plasma j et matched well with the measured value.%等离子射流点火技术在航空航天、武器工业及民用工业中均有应用。为了探索等离子射流的点火特性，对等离子射流在大气中瞬态膨胀扩展近场特性进行了数值模拟，获得了射流扩展过程中的压力、速度、温度分布以及两相界面演化特性。结果表明：等离子射流扩展过程中，射流近场逐渐形成马赫盘，并伴随射流分叉、聚合现象。正激波上游各参数均不随时间变化，下游参数随时间改变。射流前端面扩展位移计算值与实测值吻合较好。