跨声速风扇转子叶尖小翼设计与扩稳机理研究

为了揭示叶尖小翼对跨声速风扇转子气动性能的影响机理,采用数值模拟方法研究了跨声速风扇转子NASA Rotor 67附加不同叶尖小翼的气动特性,并在分析不同叶顶间隙时风扇转子失稳机制的基础上探究了叶尖小翼的扩稳机理。研究结果表明:最大宽度的压力面小翼在小间隙、设计间隙和大间隙情况下分别使风扇转子失速裕度提高32%,33.6%和70.6%。小间隙时,转子叶尖泄漏涡和叶片吸力面附面层分离是影响风扇转子失稳的关键因素,设计间隙和大间隙时,叶尖泄漏涡导致的大面积阻塞区是影响风扇转子失稳的关键。三种不同叶顶间隙情况下,压力面小翼的扩稳机制均在于有效降低了转子叶尖泄漏涡强度,减弱了叶尖泄漏涡导致的低轴向速度区流体的阻塞程度。

Design and Investigation of Blade Tip Winglet for TransonicFan Rotor

In order to reveal the influence mechanism of the blade tip winglet on the aerodynamic characteristics of the transonic fan rotor, a numerical simulation of aerodynamic performance of NASA Rotor 67 with different tip winglets was carried out. Based on the instability mechanism of the fan rotor with different tip clearance, the mechanism of stability enhancement by the blade tip winglet was explored. The results show that the fan rotor stall margin with maximum width of the pressure-side winglet can be increased by 32%, 33.6% and 70.6%, respectively, in the case of small clearance, design clearance and large clearance. At the small clearance condition, the rotor tip leakage vortex and the blade suction surface boundary layer separation are the key factors affecting the fan rotor instability. At the design and large clearance, the large blockage area caused by the tip leakage vortex affects the fan rotor instability. In the case of three different tip clearances, the mechanism of stability enhancement by the pressure-side winglet is that it effectively reduces the strength of the rotor tip leakage vortex and the degree of flow blockage in the low axial velocity region caused by the tip leakage vortex.