射流预冷对高空高马赫数下压气机性能影响的数值研究

Numerical Study on the Influence of Jet Pre-cooling on Compressor Performance under High Altitude and High Mach

为研究射流液滴与空气双向耦合流动对压气机内部流场及其工作性能的影响,以NASA Stage35为模型,基于相似理论得到高空高马赫数下相似流场和压气机进出口条件,并对多工况下不同喷水量和液滴粒径下的射流冷却湿压缩过程进行分析。研究表明:射流预冷技术可有效抑制压气机进气同比温升。液滴与空气双向耦合流动使得压气机内部流场发生变化,有效降低叶片载荷的同时使动叶内的激波后移。在空气质量流量的0~2%的射流范围内,随着喷雾粒径的增大,压气机压比先增大后减小;比耗功量随喷雾量的增多而减少。25 km高空3.5Ma工况下,5μm粒径且喷雾量为空气质量流量的2%时,液滴蒸发率超过50%,压气机出口温度下降约20%,实际比压缩耗功同比减少约12%,压气机等熵效率提升约8%。

In order to explore the influence of the two-way coupling flow of jet droplets and air on the internal flow field of the compressor and its working performance, NASA Stage35 was taken as the model, the similar flow field and the inlet and outlet conditions of the compressor under the high-altitude and high Mach based on similar theory were obtained, and the wet compression process of jet flow cooling with different water injection capacity and droplet particle sizes under multiple operating conditions was analyzed. The research shows that the jet pre-cooling technology can effectively inhibit the temperature rise of the intake air of the compressor. The two-way coupling flow of droplets and air causes the internal flow field of the compressor to change, which moves the shock waves in the rotor blade backward while reducing the blade load efficiently. In the range of 0 to 2 percent of air mass flow, the compressor pressure ratio increases first and then decreases with the increase of spray particle size. The specific power consumption decreases with the increase of spray amount. Under the condition of 3.5 Ma at an altitude of 25 km, with the particle size of 5 μm and the spray amount of 2% of air mass flow, the droplet evaporation rate exceeds 50%, the compressor outlet temperature is decreased by about 20%, the actual specific compression power consumption is decreaseed by about 12% compared to the same period last year, and the isentropic efficiency of the compressor increases by about 8%.