离心叶轮背腔复杂流态及调控方法研究进展

Review of Complex Flow Status and Control Methods for Rear Disk Cavity in Centrifugal Impeller

关键词:  离心叶轮  背腔  复杂流动  轴向推力  裕度  综述

Key words:  Centrifugal impeller  Back cavity  Complex flow  Axial thrust  Margin  Review

摘要:

因叶轮/扩压器转静间断，离心压气机级中必然存在引气腔并对级性能产生影响，中小型航空发动机/燃气轮机用半开式离心叶轮中背腔引气影响尤为突出。本文从简化及真实离心叶轮背腔流态研究、复杂流态调控方法、对级气动性能影响、叶轮/扩压器/背腔多维度耦合模拟方法等方面进行了综述，展示了背腔引气对风阻损失、轴向力平衡、油/气密封及冷却气输送等多方面重要影响，并对其可能的先进设计方法进行了分析与展望。

Abstract:

Due to the discontinuity between rotational impeller and stationary diffuser， there must be a bleed air cavity in the centrifugal compressor stage， which can affect the performance of the stage. It is more remarkable in semi-open impeller with bleed air cavity used for small size aero engine and gas turbine. Research progress including the researches of flow status in simplified and real cavity， the method for controlling complex flow status， the influence on the aerodynamic performance of stage， the multi-dimensional simulation method coupling impeller， diffuser and rear cavity are reviewed. The important effects induced by cavity bleed air on windage loss， axial thrust balance， the seal for oil and air， and cooling gas delivery are present. Also， the possibly advanced design methods are analyzed and proposed.