基于相似理论的航空发动机风扇转速换算方法的改进

基于相似理论提出一种通过变指数因子计算航空发动机风扇换算转速的改进方法.收集不同公司的某型航空发动机的巡航数据建立数据样本.采用支持向量回归机方法建立指数因子与大气温度的数学模型并利用遗传算法对模型参数进行寻优,进而得到由风扇指示转速和大气温度计算风扇换算转速的变指数因子模型.使用该模型对样本数据进行计算,并把结果与定指数因子方法求解的风扇换算转速进行对比,对改进算法与定指数法换算结果进行了误差分析.结果表明:改进后的变指数因子模型计算的航空发动机风扇换算转速具有更高的精度,同时具有良好的推广泛化性能,该方法是航空发动机风扇换算转速的一种有效算法,在航空发动机性能预测也具有实际的指导意义. 

Improved correction methods of aircraft engine fan speed based on similarity theory

One improved correction method of aircraft engines fan speed by variable index factor was proposed based on the similarity theory. The cruise data of an aircraft engine from different airlines were collected to build the data sample. Method of support vector regression machine was used to establish the model of index factor and atmosphere temperature, and the model parameters were optimized based on genetic algorithm. The variable index factor model, consisting of indicated fan speed and atmosphere temperature, was set up to calculate the corrected fan speed. The model was applied by sample data, and the results were compared with those by fixed index factor method, then the error analysis was drawn through the calculation results of two methods. The result indicates that aircraft engine corrected fan speed has higher accuracy through the method of variable index factor and the model has good generalization performance, so it is an effective approach for computing aircraft engine corrected fan speed, providing a practical guidance for the aircraft engine performance prediction.