Optimization design of a novel wind-lens using Kriging surrogate model and differential evolution algorithm

Urban wind power utilization faces challenges of low wind speeds and high turbulence. Wind-lens technology enhances turbine energy capture via aerodynamic optimization. This study proposes a novel wind-lens featuring a generatrix based on a 5-point third-order quasi-uniform B-spline curve and a diffuser outlet flange for flow concentration. Geometric parameters—contraction length, expansion length, opening angle, and flange height—are optimized via optimal Latin hypercube sampling, CFD, Kriging surrogate, and differential evolution. Results show significant flow acceleration: at a freestream velocity of 5 m/s, the throat mean velocity reaches 8.6 m/s (1.72 times) and the maximum 10.9 m/s (2.18 times). Flow analysis reveals synergy of Venturi and Bernoulli effects, enhancing suction, accelerating airflow, and reducing turbulence losses. The flange generates trailing-edge vortices, forming a stable low-pressure region that amplifies suction and flow concentration, cutting internal losses. Applied to an ASWT, the power coefficient reaches 0.71 at TSR = 3, 2.54 times the bare ASWT maximum (0.28 at TSR = 2), extending the operating range to higher TSR. The proposed method offers an effective optimization approach for urban low-wind-speed conditions, demonstrating strong engineering potential.