一种面向航空发动机数学模型的新型修正方法

A new correction method for aero-engine mathematical model

为了建立高置信度的航空发动机热力性能模型,以准确掌握发动机的性能变化,实现航空发动机非设计性能的高精度预测,提出了一种面向航空发动机数学模型的新型修正方法。在对发动机部件特性线平移和缩放的基础上,考虑旋转自由度,达到对压气机特性线旋转调整的目的。引入非线性缩放因子函数与旋转因子函数以实现在不同的工况下适应性调节压气机特性数据。基于某型涡轴发动机,开展模型修正方法仿真验证。仿真结果表明:相比于仅考虑平移与缩放双自由度的模型修正方法,所提出的考虑平移、缩放与旋转的三自由度修正方法能使模型稳态平均误差从0.901%降至0.344%,大功率变化下的模型动态平均误差从1.295%降至0.889%,模型稳动态整体修正效果分别提升了62.99%和31.31%,可满足航空发动机数学模型的高精度要求。

In order to establish an aero-engine thermal performance model with high confidence,precisely master the engine performance changes and accurately predict performance of the aero-engine at off-design conditions,a new correction method for the aero-engine mathematical model was proposed.On the basis of the translation and scaling of the component characteristic line,the rotation degree of freedom was considered to achieve the purpose of rotation adjustment of the compressor characteristic line.Nonlinear scaling factor function and rotation factor function were introduced to realize adaptive adjustment of compressor characteristic data under different operating conditions.Based on a certain turboshaft engine,the simulation verification of model correction method was carried out.The simulation results showed that,compared with the model correction method only considering translation and scaling two degrees of freedom,the proposed three-degree-of-freedom correction method considering translation,scaling and rotation can reduce the model steady-state average error from 0.901%to 0.344%,the model dynamic average error under high-power changed from 1.295%to 0.889%,and the overall correction effect of model steady state and dynamics was improved by 62.99%and 31.31%,respectively,which can meet the requirements of higher aero-engine model accuracy.