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. Based on the similarity theory, an improved method for calculating the conversion speed of aeroengine fan by variable index is proposed. The cruise data of some aeroengine engines from different companies are collected to build the data samples. The mathematical model of exponential factor and atmospheric temperature is established by using support vector regression And the genetic algorithm is used to optimize the parameters of the model to obtain the variable exponential factor model for calculating the fan conversion speed from the indicated speed of the fan and the atmospheric temperature.The sample data is calculated by using the model and the result is compared with the fan The results show that the improved rotor speed of aeroengine fan calculated by the variable exponential factor model has higher accuracy and good generalization of generalization performance This method is an effective algorithm for calculating the rotating speed of the aero-engine fan and has practical guidance in the prediction of aeroengine performance.