Seven-Zone Parametric Optimization Method for Compressor Profile with Controllable Maximum Thickness

Currently, many parametric optimization methods for designing compressor blades with a controllable maximum thickness directly use the intersection points of segmented curves on the suction side as the maximum thickness points. This approach reduces the parametric freedom and results in a distorted blade when the maximum thickness position changes. There is an urgent need for parametric optimization methods with higher degrees of freedom and greater optimization potential. In this paper, a seven-zone parametric design optimization method based on a controllable maximum thickness is proposed. The seven-zone modeling method is combined with the maximum thickness constraint method with high degrees of freedom, which has better local adjustability while ensuring the profile strength requirements. By combining the flow surface calculation method, computational fluid dynamics (CFD) analysis, and experimental measurement technique, it was found that the optimized blades exhibited a significant reduction in the total pressure loss and a notable expansion of the low-loss operating range. The flow state of the suction surface has the most significant effect on the loss reduction. The change of pressure gradient on the suction surface makes the transition or separation position move backward, and the separation and friction loss decrease, which is conducive to reducing the overall loss.