From stationary to vibrating hyperbolic paraboloid membranes: Evolution of flow fields and wind load under oblique and diagonal winds

This study investigates the mechanism of self-excited wind-induced vibrations in hyperbolic paraboloid membrane structures, focusing on the fluid–structure interaction (FSI) effects and aerodynamic instability under varying wind angels. To explore the underlying mechanism of the FSI effect, large eddy simulation and the dynamic mesh technique are employed to model the unsteady flow fields, and the results are validated against wind tunnel test data, demonstrating good agreement in both mean and fluctuating wind pressure distributions. The findings reveal that at a 0° wind angle, conical vortices form symmetrically at the windward leading edge, leading to significant pressure gradients. Structural vibration does not notably alter the mean flow field or mean wind pressure but increases fluctuating wind pressure in the mid-span region due to vortex spreading. At a 45° wind angle, the mean flow field exhibits distinct conical vortices, and structural vibration reduces the size of separation vortices while increasing their curvature, resulting in higher wind pressure magnitudes and reduced gradient distribution ranges. Instantaneous flow field analysis shows that structural vibration induces vortices to move toward the mid-span or trailing edge, significantly increasing fluctuating wind pressure in these regions. Furthermore, the correlation between wind speed and fluctuating wind pressure is analyzed, revealing that structural vibration enhances the correlation in the mid-span and trailing edge regions, particularly at a 45° wind angle. These insights provide a deeper understanding of the wind load generation mechanisms and FSI effects in hyperbolic paraboloid membrane structures, offering valuable guidance for the wind-resistant design of such flexible structures.