低稠度小偏转角叶尖涡轮气动特性分析

Analysis of Aerodynamic Characteristics of Tip-turbine with Low Solidity and Small Deflection Angle

针对气驱涵道风扇垂直起降动力系统的核心部件叶尖涡轮开展了数值模拟,掌握了低稠度小偏转角叶尖涡轮(具有高反力度特征)的气动特性和损失构成。研究表明:针对低稠度涡轮物理喉道消失、气流易分离的特点,提出低稠度小偏转角涡轮叶型。此叶型可构建气动喉道,在一定程度上弥补物理喉道消失带来的影响,其流动较常规低稠度涡轮得到了极大的改善,不存在明显流动分离,其效率为84.38%,能量利用率为70.13%,其损失构成和常规涡轮有所不同,叶尖泄漏损失高达54.15%,二次流损失为34.41%,叶型损失为11.44%。

In this paper,the numerical simulation is carried out for the tip-turbine of vertical take-off and landing(VTOL)power system with the gas-driven ducted fan,and the aerodynamic characteristics and loss composition of the tip-turbine(with high reaction characteristics)with lowsolidity and small-deflection angle are mastered.Studies have shown that:in view of the characteristics of the disappearance of the physical throat of the low-solidity turbine and the easy separation of the airflow,tip-turbine with low-solidity and small deflection angle blade profile is proposed.This blade profile can construct a pneumatic throat to compensate for the effect of the disappearance of the physical throat to a certain extent.The flow is greatly improved compared with the conventional low-consistency turbine.There is no obvious flow separation,the efficiency is84.38%,the energy utilization rate is 70.13%,and its loss composition is different from that of the conventional turbine.The tip leakage loss is as high as 54.15%,and the secondary flow loss is34.41%,the profile loss is 11.44%.