两种低转速特性外推方法的对比

Comparison of Two Extrapolation Methods for Low Speed Characteristics

低转速部件特性是航空发动机部件级模型模拟启动过程中的关键一环。针对低转速部件特性难以用试验手段获取的问题,本文研究了基于相似理论法和基于抛物线法两种低转速部件特性外推方法,详细介绍了其外推步骤。使用两种方法对同一压气机和涡轮特性进行低转速外推,并用整机模型进行节流计算,结果表明,两种方法外推的特性都符合部件特性的分布规律,具有较强的通用性。基于抛物线法外推的部件特性不匹配,需要进一步修正,但是其表征方法可以用于风车启动过程中。

Low-speed component characteristics are a key part of the simulation starting process of aero-engine component-level model. It is difficult to obtain the low-speed component characteristics by experiment. In this paper, two extrapolation methods of low-speed component characteristics based on similarity theory and parabola method are studied, and the extrapolation steps are introduced in detail. The two methods are used to extrapolate the low-speed characteristics of same compressor and turbine, and the engine model is used for throttling calculation. The results show that the characteristics extrapolated by the two methods are consistent with the distribution of component characteristics and have strong generality. However, the component characteristic mismatch based on the parabolic method needs further correction, but it can be used in the windmill starting process.