The Roll Damping Derivative Of Different Tail Structure Of Wing-body And Other Aerodynamic Characteristics

As rotating missiles are widely used, the roll damping derivatives in rotating need further study. Three wing-body models with different tails were designed to get the variation law of projectile's roll damping derivative which was relative with different aspect ratios and the number of different tail wings. In this paper, work was done from the numerical simulation and wind tunnel experiments, respectively. And it showed good agreement between the numerical results and wind tunnel experimental results. Models'roll damping derivative and other aerodynamic characteristics were according with the aerodynamic mechanism and the variation law with Mach number and angle of attack changing.In process of designing planar tail models, setting the model normal force coefficient and the pressure center position as basically the same, calculating models of primaries by aerodynamic engineering, the model of four tails in primaries was set as a benchmark model; making the tail string be the same length, changing the spanwise length and the pieces of tail, the wing-body models of six and eight tails assembly were set as two contrast models.In the wing-body models, two sets of grids were used in the numerical study of roll damping derivative. By rotating the coordinate system and using Realizable turbulence model, steady state simulation was running. The results showed:roll damping derivatives were negative, their absolute value was larger atα=4°than atα=0°; their absolute value was smaller in Ma=0.8 than in Ma=1.2; their absolute value in Ma=1.2 was greater than in Ma =2.0.Free-rolling method was used in the roll damping derivatives of wind tunnel test. In order to ensure the performance of rolling models, the dynamic balance tests and treatments were used in the models. The results showed that:roll damping derivative decreased with angle of attack increasing, and first slightly increased with Mach number increasing and then decreased, and finally increased; the roll damping derivative absolute of F8 was minimum, while the roll damping derivative absolute of F4 was maximum; other aerodynamic parameters changing with Mach number, angle of attack met the aerodynamic law. In addition, the normal force and pitching moment of the rolling model had little effect.