高超声速风洞轴对称喷管收缩段设计

Contraction design for axis-symmetric nozzles in hypersonic wind tunnel

开展了高超声速风洞轴对称喷管收缩段设计研究。利用构造的AQA分段曲线,分析喉道上游圆弧长度和喉道曲率半径是否连续对于喉部跨声速流动和喷管出口流场的影响。设计了基于三角函数和双曲函数、B样条函数的两种收缩曲线,借助控制参数使得出入口曲率半径任意可调。采用数值模拟方法分析了喉道曲率半径是否连续对于Cresci和Sivells喷管出口流场的影响。研究表明:喉道曲率半径连续是确保喷管无黏流场与设计流场一致的关键;当无法保证喉道曲率半径连续时,应使喉道上游曲率半径比下游曲率半径偏大而不是偏小。

A contraction design was conducted for axis-symmetric nozzles in hypersonic wind tunnel.The influence of arc length and curvature radius on the transonic throat flow and nozzle outlet flow was studied by constructing an AQA curve.Two new contraction curves were proposed on the basis of trigonometric function,hyperbolic function,and B-spline function.The curvature radius at the entrance and exit of the contraction can be adjusted by using these two types of curves.CFD solutions were computed to determine the influence of the throat curvature radius on the flow at the exit of a Cresci nozzle and a Sivells nozzle.The results indicate that continuous throat curvature radius is critical for the consistence between real nozzle flow and designed flow.When the continuity of curvature radius cannot be guaranteed at a throat,the upstream curvature radius of the throat is needed to be larger than the downstream one.