Investigation On Matching Law And Performance In Turbocharged Solid Propellant Ramjet

For most tactical missile propulsion devices,it is very difficult to meet the requirements of wide wire wrap,high impulse and high maneuver at the same time.Turbocharged Solid Propellant Ramjet(TSPR)is a new concept air breathing propulsion system that combines the benefits of a solid rocket ramjet and an air turbine rocket engine with both wide wrap and high performance.TSPR is one of the ideal motives for the future of tactical missiles.TSPR consists of so much components that the work process is complicated.We can establish a more reasonable TSPR performance model and provide a theoretical tool for TSPR research and design by fully understanding the matching relationship among the components of TSPR,clarifying the common work process of TSPR and finding the regulation law suitable for TSPR.In addition,as an air breathing engine system,the performance of TSPR is closely related to the type of mission and trajectory of the aircraft.Therefore,we could make a reasonable evaluation of the performance of the TSPR by researching on the typical aircraft and the typical trajectory.Aiming at the new type of engine for TSPR,firstly,the research on the matching relationship between TSPR components is carried out,and the common working equations of TSPR are established.Then the research on TSPR regulation is carried out to find the regulation law applicable to TSPR.We improve existing performance models and the predictive model of design point and off-design point performance have been established.The performance of TSPR is analyzed by using the established model.The best work area of TSPR is given.The ballistic performance evaluation of TSPR is carried out with HARM missile as the object.Finally,the TSPR ground principle prototype is designed,and the TSPR principle experiment under the ground zero speed condition is successfully carried out.The main research work and innovative results of this paper are as follows:1.According to the working characteristics of TSPR,the matching research among all components is completed and the matching relationship between the inlet and the compressor,the compressor and the turbine,the turbine and gas generator,the afterburning chamber and the inlet and outlet is established.The matching method of TSPR is established on the basis of the matching relationship among components,and the common working equations of TSPR are given.2.The research on the performance model and regulation law of TSPR is carried out.Through the comparison of various parameters and adjust the regulation law analysis shows that the ideal control law of such TSPR is that corrected speed and combustor excess gas coefficient are maintained as constant.according to the analysis of typical cases show that under the regulation,the specific impulse of TSPR is higher in the wider scope of work.Research shows that in most cases,the adjustment method of conversion speed and excess gas coefficient equal to 1 can be adopted,but for some climbing trajectories,the range of conversion speed can be relaxed appropriately.3.The calculation and analysis of the best work area for TSPR is conducted.The research shows that the TSPR based on the existing technology level is suitable for high altitude,medium and high speed flight.In the(8km,Ma2.2)to(26km,Ma3.6)range,TSPR can get high specific impulse and specific thrust simultaneously.The study also obtains the range of TSPR parameters in the best working area: the turbocharging ratio should not be more than 3.5,and the drop pressure should not be less than 10.4.The research found that during the process of TSPR adjustment,the demand of turbo-driven gas pressure and flow is not the same as that of gas generator,which makes it difficult for TSPR to be widely adjusted.In response to this problem,two solutions are proposed in this paper: one is to design the charging structure of the burning surface of propellant;the other is to design a by-pass to direct part of the propellant gas into the afterburning chamber.It is easy to implement variable combustion surface scheme,but can not be adjusted in real time,suitable for preset trajectory;exhaust program can be adjusted in real time,but the engine's working range has been reduced,the specific impulse performance is slightly reduced.In practical applications,we can choose reasonably according to the needs of the task.5.In order to solve the problem of poor climbing ability of the TSPR climbing scheme with the cruising point as the design point,this paper proposes a TSPR climbing scheme with the maximum power state as the design point.According to the calculation and analysis of typical trajectories,it shows that no matter how to adjust parameters,the thrust of TSPR is smaller than the resistance of the aircraft in some stages of the climb and it is difficult to realize the self-climbing.However,the TSPR has a good climbing acceleration performance with the maximum power state as the design point,and it can also ensure high cruise point specific impulse performance.6.Taking HARM missile as an example,the analysis of the ballistic performance of TSPR has been carried out.The results show that the TSPR-driven HARM can accelerate from(3km,Ma0.9)to(10km,Ma2.2)when the maximum power state is the design point and relative conversion speed and excess air coefficient are equal to 1,The total range of the TSPR-driven HARM is 174.4km,which is equivalent to three times the range of the same quality solid rocket-driven HARM.The average flight speed of both trajectories is quite high.This verifies the performance advantages of TSPR and the rationality of the regulation proposed in this paper.7.The design of TSPR ground prototype is carried out and the experiment of ground zero speed state is successfully carried out.The engine works stably for 20 s with an average speed of 82000 r/min.The turbocharged ratio under TSPR mode reaches 3.3,the thrust is 1877 N,the specific impulse is 4716m/s,and the combustion efficiency reaches 84.2%.The experiment reaches the design index of the surface prototype with the specific impulse greater than 4000m/s and the thrust greater than 1500 N.The experiment validates the matching design method of TSPR and corrections the parameters in the performance model.