亚声速飞机外挂物气动载荷和分离轨迹工程估算方法

PREDICTION OF AERODYNAMIC LOADS AND SEPARATION TRAJECTORIES FOR AIRCRAFT STORES AT SUBSONIC SPEEDS

本文简要介绍了一种计算亚声速飞机外挂物气动载荷和分离轨迹的工程方法。本方法分别采用源汇模型和涡格模型模拟母机的体积效应和法向力效应,采用迭代方法计及母机-外挂物之间的二阶干扰。在气动中心高速所研制的战术导弹气动特性工程计算方法的基础上,以迎角沿弹身轴线和翼片变化的流动条件代替该方法中的均匀来流条件,而建立了非均匀流场中外挂物气动载荷的计算方法。最后采用四阶的 Adams 数值积分方法求解六自由度运动方程而得到外挂物的分离轨迹。与国内外其它计算方法相比,本方法具有适用范围广、迅速、方便、实用等特点。本方法对一系列算例进行了计算,其结果与风洞实验数据具有令人满意的一致性。

A predictive method for aerodynamic loads and separationtrajectories of aircraft stores at subsonic speeds is briefly described inthis paper.The volume effects of the parent aircraft are represented bya source model,and the loading distributions on the wing-pylon arcrepresented by a vortex lattice model.An iterative method is used toaccount for second order aircraft-store interference.The store loads inthe nonuniform flows are calculated on the basis of Engineering Methodfor Predicting Aerodynamic Gharacteristics of Tactical Missiles in Uni-form Flows,developed by High Speed Aerodynamics Institute at CARDC.Variations of the angle of attack along the body axis and fins of storeare accounted for by using local rather free-stream conditions.Integra-ting six-degree-of-freedom motion equations by fourth-order Adams meth-od,the store separation trajectories are determined. As comparedwith the other current methods,the present technique has the character-istics of rapidity, convenience and ease,and wide range of application.Extensive comparisons between predictions and wind tunnel test data aremade to evaluate present method.Generally,a good agreement can beachieved.