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

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.