无翼式布局制导火箭弹俯仰操纵气动特性

Study on Aerodynamic Characteristics of Wingless-type Rocket During Pitching Control

为了研究某无翼式布局制导火箭弹进行俯仰操纵时非线性气动特性对弹箭操纵性的影响,通过模型风洞试验和数值计算相结合的方法,分析了不同马赫数、舵偏角和攻角等因素对该火箭弹气动特性的影响。对模型进行超声速风洞试验,试验结果表明,俯仰操纵负舵偏角时俯仰力矩系数导数随攻角先增大后减小,正舵偏角时俯仰力矩系数导数随攻角先减小后增大。采用ANSYS FLUENT对不同工况下该弹气动特性进行数值计算,计算结果表明,得到的俯仰力矩与风洞实验结果吻合较好,最大误差仅为4.6%。各部件气动特性分析结果表明:弹身的压心在负舵偏角时前移,正舵偏角时后移;上尾舵受弹身干扰影响法向力效率降低;负舵偏角时下尾舵的法向力系数导数随攻角减小,正舵偏角时下尾舵的法向力系数导数随攻角增大;各部件共同作用下弹箭气动特性呈非线性。

To study the influence of nonlinear aerodynamic characteristics on the maneuverability of wingless-type rocket during pitching control,the aerodynamic characteristics of the rocket under different Mach number,angle of rudder and angle of attack were analyzed by combining model wind tunnel test and numerical calculation.Model test of the rocket was conducted in a wind tunnel at supersonic speeds.The test result shows that the pitching moment derivative increases firstly,and then decreases while the rudder angle is less than zero;the pitching moment derivative decreases firstly,and then increases while the rudder angle is greater than zero.The numerical calculation was carried out to analyze aerodynamic characteristics of the rocket through ANSYS FLUENT.Numerical calculation results are in good agreement with wind-tunnel-test results.The maximum error of pitch moment coefficient is 4.6%.Further analysis on aerodynamic characteristics for each component shows that:pressure center of the rocket body moves forward while the rudder angle is less than zero,and it moves backward while the rudder angle is greater than zero.The efficiency for normal force of the top rudders decreases under the influence of downwash flow separated from the rocket body.The normal force derivative of the bottom rudders decreases while the rudder angle is less than zero,and it increases while the rudder angle is greater than zero.The aerodynamic characteristics influenced by all components is nonlinear.