| With the development of aviation technology,the design requirements to Auxiliary Power Units(APU)are more severer than before.The combination of the initiate spray and the igniter is applied widely in APU as the ignited-altitude of the APU is required higher.In this case,the performance of the initiate spray plays a vital role in the ignition reliability of the APU.It is urgent to conduct study on the spray characteristics of initiate fuel injector since there is few relative research on the small –flow spray recently.In this thesis,According to the requirements of the ignition of the combustion chamber,two cases were designed through the empirical formula and experience curve.Through theoretical analysis,numerical simulation,study on the atomization process of starting nozzle,atomization mechanism of the nozzle was revealed.The influence of the key size of exports to the centrifugal nozzle flow velocity and volume fraction distribution were studied.Study on the effects of key size on the performance of the centrifugal nozzle are summarized.According to the actual engineering application,The nozzle key dimensions that require attention and control of the structural dimensions are summarized.Ignition verification test of starting nozzle has been carried out.The performance of ground ignition and high altitude ignition test was carried out on the combustion chamber,and the rationality of the design of the starting nozzle was verified.The influence of the atomizing performance of the starting nozzle on the indirect ignition of the combustion chamber was summarized and analyzed.After analyze the test results,the case B has a better performance than case A in terms of spray characteristics and the application in combustor rig test.In conclusion,the simulation and calculation experiences were got from the whole research process could guide the flowing injector design.What’s more,the rig test results enrich the company’s data bank and do contribution to the APU ignition design. |
PDF Full Text Request