采用脉冲爆震外涵加力燃烧室的涡扇发动机性能研究

Investigation on Performance of Pulse Detonation Turbine Engine with PDC as a Duct Heater

关键词:  脉冲爆震涡轮发动机  性能  部件特性  当量比

Key words:  Pulse detonation turbine engine  Performance  Component characteristics  Equivalence ratio

摘要:

为了研究带外涵加力脉冲爆震燃烧室(Pulse detonation combustor，PDC)的分开排气涡扇发动机性能，建立了其性能模型。利用该模型对带PDC外涵加力原理性试验模型的性能进行了评估，同时选取涡扇发动机对该发动机采用PDC外涵加力后的部件特性及整机性能进行研究，并比较了等燃油流量下外涵道装有PDC和传统等压燃烧室的发动机性能。理论计算结果和实验值对比表明，加装合适的喷管结构能够大大提高该原理性试验模型的推力性能。算例的计算结果显示:随着PDC工作频率的提高，发动机总推力增加，耗油率增大；在同一工作频率下，PDC平均增压比、平均出口温度和发动机总推力在当量比1.1左右达到最大值，发动机总耗油率随着当量比的增大而增加；当PDC工作频率超过50Hz时，外涵道装有PDC的发动机总推力大于外涵道装有传统等压燃烧室的发动机推力，且耗油率要小。

Abstract:

A new model was developed to investigate the performance of turbofan engine with PDCs (pulse detonation combustors) in the bypass duct. The model was used to predict the thrust performance of an experimental system designed as a pulse detonation turbine engine with PDCs in the bypass duct. Further more，the component characteristics of a specific turbofan engine with PDCs in the bypass duct were investigated and the performance was compared with the same turbofan engine in which a traditional constant pressure combustor was installed in the bypass duct under the same mass flow rate of fuel. The results show that the predicted performance is higher than the experimental data，indicating that the experimental performance can be improved when suitable nozzle is placed downstream of the PDC exit. Additionally，while increasing operating frequency，the total thrust and specific fuel consumption of the engine increase. When the operating frequency holds constant，the pressure ratio，the averaged exit temperature of the PDC and the total thrust of the engine reach maximum at the equivalence ratio about 1.1，but the specific fuel consumption rate increases with increasing of equivalence ratio. Contrasted with the traditional constant pressure combustor in the bypass duct，the total thrust and specific fuel consumption are better when the PDC in the bypass duct operates with a frequency higher than 50Hz.