Adjoint Optimization Method for Transonic Compressor Blade Based on Mesh Deformation Technique

In order to study the influence mechanism of three-dimensional compressor blades on shock waves and complex secondary flow and improve the corresponding control technology，an adjoint optimization platform is established for a compressor blade，by coupling adjoint optimization method，mesh deformation technique and numerical simulation technique. To improve the compressor isentropic efficiency，the blade of Rotor 37 is optimized at 98% choking mass flow rate. After the blade optimization，the compressor isentropic efficiency rises by 0.79%，the total pressure ratio grows by 0.48%，the mass flow increases by 0.71%，and the outlet entropy generation drops by 3.85%. More importantly，the blade optimization can improve the efficiency and total pressure ratio at nearly all working conditions，in particular，the performance improvement is more significant at larger inverse-pressure-gradient conditions. The flow mechanism shows that after the blade is optimized，the leading edge of the blade is offset to the back of the blade，and the trailing edge is offset to the leaf pot，the distribution of the air inlet and outlet angle along the height of the blade is adjusted to reduce the mixing loss caused by uneven outlet air flow. A bow-shaped structure is formed at the leading edge of the blade，which reduces the peak Mach number of the leading edge and makes the boundary layer better develop，the position of the maximum blade curvature is adjusted to make the airflow turn more reasonably. Besides，after blade optimization，the load on the middle of the blade moves forward，and the shock wave is delayed，which reduces the interference between the shock wave and the boundary layer so that the airflow after shock waves is improved. In addition，the blade optimization also reduces the load on the rear of the blade，which further results in better flow characteristics. The above results demonstrate the feasibility and effectiveness of the adjoint optimization method for compressor blade optimization. © 2022 Journal of Propulsion Technology. All rights reserved.