以某跨声速压气机为研究对象, 采用CFD技术结合欧拉-拉格朗日法对进口均匀喷雾压气机气液两相流场进行数值模拟, 研究了不同喷湿条件(液滴粒径和喷湿量)对压气机性能及稳定边界的影响规律, 并通过喷湿前后转子进/出口速度三角形、轮缘功及温-熵图过程线解释了性能变化机理。结果表明：湿压缩能够提升压气机的压比和效率, 但在喷湿前后不同的工况对比条件下, 湿压缩对压气机耗功的影响有不同的趋势——在等流量条件下湿压缩提升了压气机比耗功, 在等压比条件下湿压缩能够降低压气机比耗功；喷水后压气机失速流量增大, 且失速流量的增大程度跟压比升高的程度呈正相关性；在等流量条件下, 液滴蒸发冷却作用会降低转子出口气流温度, 使出口气流密度提高、轴向速度降低, 引起扭速和轮缘功增大, 这是等流量下压气机级压比升高的主要原因；另外, 液滴粒径越小, 蒸发冷却效果越显著, 导致压气机压比、耗功等提升的效果越强；大粒径液滴由于蒸发冷却作用较弱, 而液滴破碎效应较强, 会带来额外的流动损失, 导致压气机效率下降。
In this paper, the CFD technology combined with Euler-Lagrange method is used to simulate the gas-liquid flow field in a transonic compressor under inlet uniform fogging. The influence of different fogging conditions (droplet size and spray flow rate) on performance and stability boundary of the compressor is studied. The mechanism of performance variation is explained by the change of rotor inlet/outlet velocity triangle, specific work and process lines on temperature-entropy diagram. The results show that wet compression can improve the pressure ratio and efficiency of the compressor. However, the influence of wet compression on power consumption of the compressor has different trend under different comparison conditions. Under the condition of equal mass flow, wet compression can increase the specific work, while under the condition of equal pressure ratio, wet compression can reduce the specific work. The stall flow rate increases after fogging, and the increase degree of stall flow rate is positively correlated with the rise of pressure ratio. Under the condition of equal flow rate, the evaporative and cooling effect of the droplet can reduce the temperature of the air flow at outlet, causing increase of air density and decrease of axial velocity, and finally leading to the enhancement of the torsion speed and the specific work of the rotor. This is the main reason for the rise of compressor stage pressure ratio under the condition of equal flow rate. In addition, the smaller the droplet size is, the more significant the evaporative cooling effect is, and the stronger the effect of improving the compressor pressure ratio and power consumption is. Large droplets have weak evaporative cooling effect and strong droplet breakup effect, which will bring additional flow loss and reduce compressor efficiency.
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