超声速X形鸭翼-弹身组合体涡迹发展

应用蒸汽屏方法研究超声速X形鸭翼-弹身组合体涡迹发展。观察了起源于鸭翼后缘的四个翼涡在横截面上形成的“蛙跃”和上反角二翼涡与弹身一对对称脱体涡形成的“混合式蛙跃”现象。在临近蛙跃距离时,有不稳定特性发生。文中还给出了细长体理论计算的涡迹路径跟实验数据比较,结果表明:如果各个旋涡的初始位置和相对强度适合,这种数学模型可计算导弹上的各个旋涡路径,二者存在的差别,可能是由于计算未能模拟涡面和涡量耗散的缘故。为了有助于理解导弹的气动特性,用少量的离散涡计算涡迹路径,作为工程估算是适宜的。

VORTEX DEVELOPMENT ON CRUCIFORM CANARD CONFIGURATIONS AT SUPERSONIC SPEEDS

The vapor-screen technique has been successfully used at supersonic speeds to determine the development of the longitudinal vortices. The four vortices originated from the trailing edge of canard fins, which tend to "the leapfrog" in a crossflow plane, or the two vortices of the dihedral fins and a pair of symmetric body vorticas, which tend to " the hybrid leapfrog " in another crossflow plane, could be observed. Phenomena of vortex unstability could happen when vortices approached to the leapfrog distance . Furthermore, the results of predicted vortex trajectories based on slender body theory were compared to experimental data. It has been shown that the mathematical model presented herein could predict the paths of the individual vortices that developed over the missile, provided their initial locations and relative strengths were appropriately specified. Some differences between experimental data and predicted vortices were possibly due to effects of vorex sheets and diffuse vorticity. In order to aid in understanding missile aerodynamics, the theoretical methods, based on a spare number of discrete vortices, are capable of adequetely predicting vortex paths as an engineering evaluation.