S2 反问题法是重要的初始设计评估手段。通过选择合理的损失模型并进行验证,得到了适用于大涵道比风扇的S2 反问题评估方法,并系统研究风扇关键几何参数对风扇气动效率的影响规律。结果表明:当进口机匣半径增大到一定程度,增大半径对于风扇效率的改善已不明显;当进口轮毂比大于0.295 时,风扇效率将急剧下降;流道形式采用等外径或近似等外径设计时,风扇具有更高的效率;而风扇出口尺寸的选择除满足流量系数的要求之外,还应考虑与下游部件的匹配,以提高整个压缩系统的效率。
The S2 inverse problem is very important in a design process. With the use of a reasonable and verified loss model, an evaluation method is developed for the civil high bypass ratio fan, and the effect of key geometric parameters on the efficiency of the turbofan is investigated. It is shown that, when the radius of the inlet casing is increased to a certain extent, the further increase of the radius does not obviously improve the turbofan efficiency. When the hub ratio is greater than 0.295, the fan efficiency will fall sharply. The constant case diameter design is effective in the improvement of the turbofan efficiency. In the determination of the outlet size, not only the requirement of the flow coefficient, but also the matching with the downstream part have to be taken into account to improve the efficiency of the whole compression system.
[1] Michael T T, Scott M J, et al. A probabilistic assessment of NASA ultra-efficient engine technologies for a large subsonic transport[C]. ASME Turbo Expo 2004, Vienna, Austria, June 14-17, 2004.
[2] Michael T T, Scott M J. An updated assessment of NASA ultra-efficient engine technologies[C]. 17th International Symposium on Air Breathing Engines, Munich, Germany, September 4-9, 2005.
[3] Baker N, Rolt A. New environmental friendly aero engine core concepts[C]. 18th International Symposium on Air Breathing Engines, Beijing, China, September 2-7, 2007.
[4] Korsia J J. VITAL-European R&D program for greener aero-engines[C]. 18th International Symposium on Air Breathing Engines, Beijing, China, September 2-7, 2007.
[5] 梁春华. TECH56技术计划即将结束[J]. 航空发动机, 2004, 30(1): 46- 46. Liang Chunhua. TECH56 plane is coming to end[J]. Aeroengine, 2004, 30 (1): 46-46.
[6] Came P M, Robinson C J. Centrifugal compressor design[J]. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 1999, 213(2): 139-155.
[7] Johnsen I, Bullock R. Aerodynamic design of axial flow compressors[R]. Washington DC: NASA, 1965.
[8] Koch C C, Smith L H. Loss sources and magnitudes in axial- flow compressors[J]. Journal of Engineering for Power, 1976, 98(3): 411-424.
[9] Wisler D C. Loss reduction in axial flow compressors through low-speed model testing[J]. Journal of Engineering for Gas Turbines Power, 1985, 107(2): 354-363.
