Research On The Key Technology Of New Dual Throat Fluidic Vectoring Thrust Nozzle

Vectoring thrust technology is the basic requirement for the fifth generation fighter. Fluidicvectoring nozzle has been researched widely as it will be a realizable solution of thrust vectoring in thefuture. However,all fluidic vectoring nozzle concepts that have been developed till now inevitablyconsum high-pressure secondary injection. A new kind of fluidic vectoring nozzle is developed based onthe Dual Throat Nozzle (DTN) in this article, which is installed an inner channel in the nozzle. The newDTN technique doesn’t consum any secondary injection from the engine, but also produces steady andefficient vectoring deflection.Numerical simulations, optimal designs and experiments are carried out to study the keytechnologies of the new DTN. The thrust vectoring efficiency and the thrust vector angle of the newDTN optimization model are greater than any other fluidic thrust vectoring concept reported in theliterature. Especially, under NPR=10, the thrust vector angle also can reach21.3degree. Two dual throatnozzles are studied with the different of scales by unsteady simulation. The complex flow and themechanism of the cavity are analyzed carefully. Before the nozzle produces the final stable positivevector angle, the negative vector angle appears at first, which is about the60%of the maximum positivevector angle. During the vector starting process, the vector gradient value is quite large which is nearly8degree per millisecond, and the dynamic response time is very short.So far as we know, there is norelative report about this phenomenon yet.To reduce the effects of thrust vector on the dischargecoefficient and solve the problem of increasing30%mass flow of the engine at the afterburner state, abypass jet flow is introduced. Form the simulation results, the method can meet the requirements.The dynamic experiment is carried out.The dynamic vector rates of the new DTN are50degree/second,40degree/second and34degree/second under NPR=3,5and10, separately. When thenozzle is under no vector stateat the initial moment, the dynamic hysteresis time is less than1ms. And ifthe nozzle is under vector states at the initial moment, the dynamic hysteresis time is no more than10ms.