流路参数对收扩喷管内流特性影响的数值研究

用经冷态缩比模型内流特性试验验证的三维有黏定常程序,对某轴对称收扩喷管进行了收敛调节片长度、喉道圆弧半径、扩张调节片长度和喷管扩张面积比对内流特性影响规律的计算研究.研究结果表明：收敛调节片长度和喉道圆弧半径主要是对收敛半角较大工况的流量系数有一定的影响,可以在确保收敛半角小于45°前提下适当减小收敛调节片长度;扩张调节片长度和喷管扩张面积比主要是对推力系数影响较大,扩张调节片长度和喷管扩张面积比的选择应在确保扩张半角小于16°前提下力争气流完全膨胀.

Computation of effect of different nozzle parameters on internal performance of convergent-divergent axisymmetric nozzle

The numerical simulation on convergent flap length, nozzle throat arc radius,divergent flap length and nozzle expansion ratio affecting the internal performance of an axisymmetric convergent-divergent nozzle was conducted by applying a three-dimensional(3-D) viscous flow program that the results of the simulation were compared with that of the scale model experiments.The investigation shows that:convergent flap length and nozzle throat arc radius have some effects on the flow coefficient under the condition of a big convergent half angle,and convergent flap length can be properly reduced on condition that convergent half angle is less than 45 degrees;divergent flap length and nozzle expansion ratio have big effect on the thrust coefficient,and selected divergent flap length and nozzle expansion ratio shall work hard for fully expanded nozzle flow on condition that divergent half angle is less than 16 degrees.