Overall Aerothermodynamic Analysis On An Improved Micro-turbojet Engine And Diffuser Design

Micro turbine engine, with its merits in low cost, large power, small size, light weight, highenergy density, easy to maintenance and storage, is highly value and expected to be widely used infields of propulsion system and energy system.We analyze the overall performance and retrofitdesign a micro turbojet engine which is improved from another engine. At the same time, we do theoptimization design of the consective passage diffuser through the numerical simulation method.And we study the coupling characteristics between the compressor and the combustion chamberwhen asseble diffusers with different outlet blade angle. The main works is as follows:1. Considering the component design capabilities, combined with the current materialproperties. We simulate the the performance of MTJ17with the software Gasturb, calculate theoverall engine design point performance parameters, initially identified MTJ17componentperformance parameters.2. Study the influence of different splitter vane’s length and circumferential position on theperformance of consective passage diffuser. When the inlet airflow is subsonic, if the splitterstarting from the one-third of the turn section, the splitter can be shortest and effectively curb thedevelopment of the flow separationthe zone which on the side of main blade suction. When thesplitter blade offset to the suction of main blade, we find an optimum circumferential positionwhich can make the diffuser performance best.3. Study of the different outlet angle of blade influence on the performance of diffuser, analysethe aerothermodynamic coupling characteristics of compressor and combustion chamber when thecompressor assemble diffuser with different outlet blade angle. The study showed that, when thediffuser vane outlet angle is-10°, the engine performance is best.4. Under the condition of the same inlet flow mass, study the influence of the entrance swirlangle on the performance of combustion chamber. The angle within the range of10°, efficiencyand total pressure recovery coefficient of the combustion chamber did not change significantly, thetotal pressure recovery coefficient of only reduced0.2%, combustion efficiency is almost nodifference.When the swirl angle add to20°, compared to the prototype, the total pressure recoverycoefficient reduced by1%and the combustion efficiency decreased by0.6%. Moreover, the greaterthe inlet air swirl angle is, the outlet temperature field is more confusion.5. Realize the structural engineering of MTJ17. We have design and analysis the structural of MTJ17which on the basis of MTE16’s structure.