Research On Thrust Characteristics Of Solid Rocket Motor Based On The Catalytic&Oxidative Secondary Flow Injection

In recent years,the random thrust control is becoming an important research field.The working process of traditional solid rocket motor is designed in advance,and the thrust and the propellant distribution cannot be adjusted randomly.Achieving the random thrust control will be a breakthrough in the development of solid rocket motor.The Fluid Nozzle Throat(FNT),which injects secondary flow at nozzle throat,is one of practicable concepts to realize the random thrust control of solid rocket motor.To explore the effect of thrust adjustment characteristics of FNT by using different working medium,a thermal motor of using catalytic and oxidizing secondary flow was design and completed first,which can be used in the thermal thrust-control experiments.At the same time,the developed thermal motor and test program can realize a rapid exchange between catalytic and oxidizing experiments.And then both catalytic and oxidizing thrust-adjust experiments were performed.Nitrogen with copper and strontium perchlorate solution were used in the catalytic and oxidizing experiments respectively.Compared with the experimental results without catalytic(nitrogen),after mixing the copper into nitrogen,the response speed of thrust modification speed up significantly;the test results verify the feasibility of a catalytic secondary flow to improve thrust adjustment process of FNT and show the degree of improvement for the first time.In comparison to the results of no oxidation(water),strontium-perchlorate-solution secondary flow plays a certain effect in improving the choke performance of FNT.However,due to the oxygen-poor propellant used in the test,the improvement effect is not obvious with weak secondary combustion and small amount of heat production from the oxidation between secondary flow and propellant gas at the nozzle throat.At last,a CFD study was performed to observe the trail of copper in the catalytic experiments.The results show that the injected copper from throat can move to the flame area of the propellant closely before forming stable fluid throat;thus,the injected copper can change the chemical process in this area,which improves the burning rates in the tests.The devices and results here establish the foundation to the catalytic and oxidizing secondary flow study of FNT in the future,and also provide information to engineering application of FNT.