Effect of inlet crossflow on the discharge coefficient of leading edge jet impingement

The discharge coefficient of a single hole jet impingement on a circular target surface was measured. The velocity ratio of inlet crossflow to jet flow was changed from 0 to 0.3 for jet Reynolds number in the rang 15,000 to 40,000, simulating the different magnitude of inlet crossflow at each of a row of impingement holes encountered in a real engine leading edge impingement cooling scheme. The effect of inlet crossflow velocity ratio and jet Reynolds number on the discharge coefficient was investigated. The results show that the discharge coefficient of jet impingement increase with jet Reynolds number, with the maximal increment of about 7%, and decrease with inlet crossflow velocity ratio, with the maximal decrement of about 15%. Correlations between jet Reynolds number and discharge coefficient, and between inlet crossflow velocity ratio and discharge coefficient were obtained based on the experimental data.