应用于混合排气涡扇发动机建模的容积法改进

Improvement of Utilizing Volume Method in Mixed Flow Turbofan Engine Modeling

使用容积法建立混合排气涡扇发动机模型需要选取容积与转子来计算发动机的状态量,为压气机及涡轮部件的特性图插值与计算提供输入数据。旧的容积选取模式需要通过近似计算步骤间接得到混合室入口内涵气流的状态量,降低了模型的精确度。提出了一种新的低压涡轮后容积的选取方式,可以直接计算混合室入口内涵气流的状态量,提高了模型的精确度。以基准模型为参照的仿真验证显示,将旧的容积选取方式更换为新的容积选取方式使得模型的仿真误差从10-2等级下降到10-6等级。

Using volume method to establish a mixed flow turbofan engine numerical simulation model required to select volumes and rotors to calculate engine state values which provided input data for the map- interpolation and calculation of compressors and turbines. The old volume selection method needed an approximate computation step to get the states values of the inner stream into the mixer indirectly. A new method of selecting volume after the low pressure turbine was proposed. The new volume selection method could get the states values of the inner stream into the mixer directly and improved the accuracy of the model. Using a bench mark model as reference,simulation showed that replacing old volume selection method with new method reduced the modeling error from 10^- 2 level to 10^-6 level.