Investigations On Combustion Organization Technology Of Trapped Vortex Powdered Fuel Ramjet

Powdered fuel ramjet is a new kind of ramjet, it employs high energetic powder asfuel which hlods both the advantages of the liquid fuel fuel ramjet that of highcombustion efficiency, high energy, altered fuel mass and the advantages of the solidfuel ramjet that of simple structure, high reliability, convenient for maintenance, suit forlaunch etc. As a novel ramjet, how to organize the fuel burning process is the pointwork. In this dissertation, with the method of numerical simulation and direct-connecttests, the process of fuel burning organization is analyzed, and the work providesguidance for improving the combustion efficiency of this kind ramjet.Based on the particle trajectory model, the numerical simulation method of thethree dimensional two-phase combustion flow field in the combustion chamber wasbuild up, and the direct-connect rocket engine ground test stand was set up for thepowdered fuel ramjet. The the correctness was validated by ramjet direct-connect testshow that without consider serval factors, the numerical simulation method coulddiscrible the interaction in the chamber.The impact on combustion process of different magnesium powdered fuel ofdifferent granularity was numerical simulated in three types of powdered fuel ramjets,the impact of the structure differences of the ramjet on the chamber temperature filedstructure, the powder ignition and combustion process was analyzed, and theperformance of the three jets was evaluated according to the above analysis, and then atrapped vortex powdered fuel ramjet was designed and manufactured. The feasibility oframjet start-up was proved by the direct-connect tests, and the combustion oscillationduring the experiment was conquered. The superiority of the trapped vortex powderedfuel ramjet in restraining combustion sediment and improving combustion efficiencywas testified by a contract experiment.The investigations in working character of the ramjet were conducted. By means ofnumerical simulation and direct-connect tests, the principles that how the injectionforms and proration of the primary and the secondary air flow affect the start-up,combustion sediment combustion efficiency were analyzed, and these instruct to findout the optimal working condition of the jet. The burn out point was investigated withthe numerical simulation method, the result show that a lower burn out point could bereceived when the primary air injected strightly. And carried out a way to duel with thecombustion sediment without harming the stable combustion.The effect that the physical and chemical character of the powdered fuel on thejet’s performance is investigated. By means of numerical simulation and direct-connectexperiments, the effect that the granularity and the high efficiency packing technologyof the magnesium on the jet combustion efficiency was investigated, the result show that a uniform granularity could help get a better combustion efficiency. Direct-connectexperiment testified the feasibility of employing boron as fuel into the powdered fuelramjet by adding boron into the powdered magnesium fuel, and several tips of theapplication was mentioned, such as aggregation.