| Rotating missile is a kind of missile arrow that rotates around its axis of symmetry in flight.It can control pitch and yaw in two directions through one or two pairs of canard.The coupling of canard deflection and missile rotation will cause more complicated flow phenomenon during missile control.This article adopts the numerical simulation and experimental validation of the method of combining magnus effect of rotating missile corresponding flow mechanism,rotating flow around a cylinder is simulated,the theoretical analysis and experimental research,the flow function caused by a rotating cylinder is analyzed,and the asymmetry of flow separation resulting in the surface of the rear free shear layer,the change of shedding vortex position;Magnus moment characteristics of Bang-Bang control rotating missile,positive/cosine control rotating missile,direct force/aerodynamic composite control rotating missile and rotating missile at high altitude are studied by numerical simulation method.The complex flow phenomenon caused by the coupling of duck canard deflection and missile rotation is analyzed.At the same time,the equivalent static condition of the average normal force coefficient of the missile is given,the influence of the altitude condition on the magnus moment characteristics of the missile is analyzed,and the aerodynamic characteristics of the missile under the condition of transverse jet flow are analyzed.The research results can provide reference for aerodynamic characteristics analysis,engineering practice and application of rotating missile.The thesis mainly completed the following aspects of work:（1）In this paper,the magnus effect flow mechanism of a rotating missile,the flow around a rotating cylinder,is studied,and the asymmetry of surface flow separation caused by rotation is revealed,which leads to the change of the position of free shear layer and shedding vortex behind the cylinder.The flow around a rotating cylinder with high Reynolds number（Re=20000～90000）was numerically simulated,theoretically analyzed and experimentally studied.The flow field behind the rotating cylinder was measured by hot-wire anemometer in a low-speed wind tunnel.The velocity distribution characteristics and turbulence distribution characteristics at different sections behind the rotating cylinder were analyzed.The results of numerical simulation and theoretical analysis are compared with the experimental values.On the basis of proving the accuracy of the numerical simulation results and theoretical analysis results,the transition,flow separation and Magnus force of the rotating cylindrical boundary layer are studied.The results show that:When the Reynolds number of free incoming flow is constant,the turning points and flow separation points on the lower surface of the cylinder（in the direction of incoming flow and linear velocity）will move backward with the increase of relative rotational speed,while the turning points and flow separation points on the upper surface of the cylinder（in the direction of incoming flow and linear velocity）will move forward with the increase of relative rotational speed.The flow separation on the upper surface of a cylinder results from the decrease of kinetic energy caused by viscous friction and adverse pressure gradient,and the movement direction of the wall is opposite to the mainstream direction,which intensifies the dissipation of kinetic energy caused by viscous friction.The flow separation on the lower surface of the cylinder is the result of backflow due to the large adverse pressure gradient on the leeward side which makes the fluid near the wall unable to follow the wall.（2）The magnus moment characteristics of rotating missiles with Mach numbers of 1.3 and1.5 at different altitudes and angles of attack are numerically simulated,and the variation of magnus moment characteristics with altitude is analyzed.The results show that the direction of magnus moment of rotating missile changes with the increase of altitude.When the Mach numbers are 1.3 and 1.5 and the Angle of attack is 30°,the direction of magnus moment changes from negative to positive with the increase of altitude.The direction of the rotating missile’s Magnus moment will change with the increase of the angle of attack.When the Mach number is 1.5 and the altitude is less than 10km,the direction of Magnus moment changes from positive to negative with the increase of the Angle of attack.When the Mach number is 1.5 and the altitude is greater than 10km,the direction of magnus moment changes from positive to negative and then positive with the increase of the Angle of attack.（3）The aerodynamic characteristics of Bang-Bang control rotating missile were analyzed by numerical simulation method,and the variation rule of aerodynamic characteristics of the missile after rotation was revealed.The differences of normal force characteristics and lateral force characteristics of the missile with Bang-Bang control and without canard control were analyzed.The results show that the change of the wash direction caused by the missile rotation coupled with the deflection of the canard plays a major role in the change of the lateral force of the missile body,and the change of the wash direction leads to the change of the lateral force of the missile body and the tail.Compared with the rotating missile without canard control,it is found that the periodic mean lateral force coefficient of Bang-Bang control rotating missile is smaller and the periodic mean normal force coefficient is larger.The static equivalent canard deflection Angle of the normal force coefficient of the missile is 2/πof the maximum mechanical canard deflection Angle during a rotation period,and the control direction depends on the reversing moment t0.（4）Numerical simulation is used to analyze the aerodynamic characteristics of positive and cosine controlled rotating missile,and the effects of duck canard’s positive and cosine steering on the characteristics of normal force,lateral force and yaw moment are revealed.The results show that when the same maximum canard deflection angle is used,the periodic average normal force coefficient of the missile under positive and cosine control is smaller than the normal force coefficient of the static×layout,and close to the normal force coefficient of the static+layout.The absolute values of the periodic mean lateral force coefficient and the periodic mean yaw moment coefficient of the missile are larger than those of the static×pattern layout and+pattern layout.The absolute value of yaw moment coefficient of missile under forward and cosine control is smaller than that without control.The rotation effect is the reason for the lateral force of the rotating missile with positive and cosine control mode,and the lateral force of the canard and tail is dominant.The aerodynamic characteristics of the missile under coning motion are analyzed.The changes of the ideal synthetic angle of attack have little effect on the periodic average lift coefficient and the lateral force coefficient,and the absolute value of the periodic average yaw force coefficient and the periodic average drag coefficient increase.（5）Based on the polyhedron/hexahedron core grid technology and MRF model,the aerodynamic characteristics of a rotating missile with direct force（transverse jet）/aerodynamic composite control in the range of Mach 0.2～0.7 were numerically simulated,and the variation of aerodynamic characteristics was analyzed.The results show that for the normal force,the direct force plays a larger role when the Mach number is less than 0.35.With the increase of the Mach number,the aerodynamic force gradually becomes dominant,and the contribution of the transverse jet to the normal force gradually decreases.For the pitching moment,when the Mach number is less than 0.3～0.45,the effect of direct force control is better,and when the Mach number is greater than 0.3～0.45,the effect of aerodynamic control is better.As for the lateral force,the lateral jet during the pitching control of the missile will have a great influence on the lateral force,and even change the direction of the lateral force. |
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