Experimental Research On Vehicle Control Technology Based On Passive Fluidic Thrust Vectoring Nozzle

Thrust vector control technology for aircraft maneuverability enhancements makes it become one of the key technologies necessary for future aircraft;it has gone from mechanical to active fluid to passive fluid type of development.The passive fluid thrust vectoring nozzle based on Coanda effect has the advantages of "fixed surface type,low energy consumption,quick response of main jet deflecting",which makes it have wide application prospect.However,the problem that the control law caused by the static deflection of the main jet,which is characteristic of the fluid thrust vector,is not continuous severely hinders its practical engineering application.In this paper,based on the passive fluid thrust vector technique,a wedge-shaped passive fluidic thrust vectoring nozzle with continuous main jet deflection is made by changing the nozzle configuration and secondary flow control.PIV was used to study the static deflections of the main jet at different cross sections of the wedge nozzle and flow field characteristics.The continuous control curve of the wedge nozzle force/flow vector angle with the opening of the secondary flow valve was obtained.The three-dimensional effect explains the reason of the static continuous deflection from a macro perspective.Finally,a missile wind tunnel model incorporating wedge nozzle was designed.The open-loop control of the missile was studied only when the fluid vector nozzle was controlled.The control curve of the missile's yaw angle with the valve opening under different combinations of wind speed and power was obtained.Given the valve signal of the step,the dynamic response of the missile is studied to obtain the dynamic response curve.Combined with the five-hole probe miniature air data sensing system,a closed-loop feedback system was designed using image programming language to verify the control ability of the passive fluid vector nozzle.The results show that: The wedge-shaped passive fluidic thrust vector nozzle designed can realize continuous control of static deflection of the main jet,the maximum average flow/force thrust vector angle is 15°/14°;It is also capable of continuously changing missile yaw attitude,the fastest dynamic response time of yaw is 0.9s.