局部及全叶高合成射流对高速压气机静叶栅流场结构的影响

数值研究了合成射流控制高速压气机静叶栅吸力面角区分离,对比分析了不同射流结构对叶栅内流场结构及气动性能的影响。研究结果表明:合成射流通过周期性地吹气和吸气推迟角区分离、降低总压损失,由于吹气和吸气阶段的作用效果不同,使得叶栅出口损失系数的改善效果呈现出周期性波动。合成射流对通道涡以及角区二次流的有效控制是其取得良好控制效果的关键,当冲角为2°时,局部、全叶高方案最大可使总压损失系数分别降低22.2%和23.8%。由于局部叶高方案无法控制叶展中部的流动,造成该区域的尾迹损失增大,从而导致其流动控制效果弱于全叶高方案。两种射流结构都具有良好的变工况适应特性,全叶高方案在大冲角时逐渐体现出其优势,当冲角为4°时,总压损失系数的改善幅度相比局部叶高方案提高了2.8%。 

Influence of part-span and full-span synthetic jets on theflow structures within a high-speed compressor stator

A simulation study on the use of synthetic jets for corner separation control on a high-speed compressor stator cascade was conducted. The effect of two jet configurations on flow structures and aerodynamic performance were compared. Results indicated that by periodically blowing and suction, synthetic jets could delay the corner flow separation and reduceing the total pressure loss coefficient significantly. Due to different control effects at different control phases, the loss coefficient at cascade outlet presented a feature of periodic fluctuation. The key for the effectiveness of synthetic jets lied in its control on passage vortex and corner secondary flow. At the incidence angle of 2°, the maximum loss reductions obtained by part-span and full-span configurations were 22.2% and 23.8%, respectively. The part-span configuration could not control the midspan flow, hence the wake loss was higher in this scheme and the control effect was weaker than the full-span one. Both jet configurations showed good adaptation characteristic at off-design conditions, while the full-span configuration could take advantage at relatively large incidence angles. At the incidence angle of 4°, the observed magnitude of total pressure loss coefficient of the full-span configuration was 2.8% higher than that of the part-span one.