We investigate the flow field characteristics and impact load behavior during the vertical water entry of a bio-inspired Northern Gannet model. Combined experimental and numerical methods were employed to characterize the multiphase flow dynamics during the air–water transition. A physical gannet head model and a set of conical reference models were fabricated based on biometric profiles. Flow features, cavity evolution, and load variations during water entry were analyzed over distinct impact velocities. Compared to a cone head model with an equivalent maximum cross section at the same entry velocity, the gannet head model induces more pronounced cavity retraction and generates lower free-surface disturbance. Notably, the cavity sealing occurs earlier for the gannet-inspired geometry. Numerical simulations further show that the bio-inspired contour yields smoother pressure and velocity gradients, leading to a reduction in peak acceleration of approximately 14%−25% compared with the conical models. The theoretical force derived for the conical model captures the overall trend of the numerical results. Furthermore, a simplified two-dimensional model was simulated based on the characteristic diving posture of the gannet, with wings swept backward and feet retracted. The acceleration profile and its peaks were analyzed to correlate with the contact conditions between the model and the water.
Wu et al. (Wed,) studied this question.