火箭发射场坪排焰道口射流研究

Jet from Exhaust Tunnel Outlet on Rocket Launch Site

为了研究火箭发射场坪上排焰道口射流流场的弯曲变化规律,基于亚声速直线射流的理论公式,提出一种横风场中亚声速弯曲射流分析方法。推导了非均匀风场作用下亚声速弯曲射流轴线方程,以及弯曲射流半宽、横截面速度、质量流量和轴线速度的近似公式;在恒定风速横风场条件下采用近似公式和计算流体力学(CFD)两种方法计算不可压缩弯曲射流的轴线和速度分布,基于CFD结果对近似公式的参数进行修正,根据近似公式参数变化分析初始半宽和速度比对射流的影响。结果表明:近似公式可以较准确地描述射流现象;初始半宽的变化对射流形状影响较小;速度比的变化对射流形状具有显著影响;所采用的理论方法在分析发射场坪排焰道口射流时具有可行性。

A method for analyzing the subsonic winding jet in the non-uniform wind field based on the theoretical formula of subsonic linear jet is proposed to research the change law of jet from the exhaust tunnel outlet on the launch site.The axis equation of the winding jet under the non-uniform wind field,and the approximate formulas of jet half-width,velocities on cross sections,flow mass and velocities on axis are derived,and the velocities of incompressible winding jet under the conditions of constant wind speed,different initial half-widths and different speed ratios are calculated by using approximate formulas and computational fluid dynamics(CFD)method.The parameters of the approximate formulas are adjusted based on CFD results,and the influences of different initial half-widths and speed ratios on jet are analyzed.The results show that the approximate formulas can be used to calculate jet accurately,the change in initial half-width has little influence on jet,and the change in speed ratio has more influence on jet.The proposed method is feasible for analyzing the jet from exhanst tunnel outlet on rocket launch site.