Effect of Profile Shape and Cascade Solidity, Inlet Mach Number and Incidence Angle on the Performance of a Subsonic Compressor Blade Cascade

Abstract This study is concerned with aerodynamic research on effect of a blade profile shape and different cascade solidities on aerodynamic performance of a subsonic compressor blade cascade. Each geometric variant regarding blade profile and solidity was tested at inlet Mach numbers in range of MR1 ∈ 〈0.45∼0.87〉 and various inlet flow angles to resolve loss buckets. Corresponding Reynolds numbers were in range of Re ∈ 〈1·10E 06, 1.6·10E 06〉. To check the effect of the main flow parameters, a range of inlet flow conditions including AVDR was investigated. General trend of losses increasing with increasing inlet Mach number was confirmed. Dramatic increase of losses was observed at the highest inlet Mach number MR1 = 0.86. This was the only supercritical value in the investigated inlet Mach number range. Losses increased approximately 2 times as compared to the next lower inlet Mach number MR1 = 0.76. In addition, the sensitivity of the cascade performance on the incidence angle was confirmed by resulting loss buckets. Not only that, we confirmed the effect of solidity, and as can be seen from Koch smith’s profile loss relational expression in general, as solidity increases, profile loss increases, but in regions where flow is unstable, it was confirmed that the secondary loss and flow instability were resolved, and the opposite result (low loss) was shown. Finally, it was confirmed that the reduction of the leading edge (L.E) loss based on the improvement of the thickness distribution (polynomial type and new thickness type) improved the loss value by about 10% at the near choking and stall points.