An Experimental and Numerical Investigation of Flow Over a Hydrofoil in Transient Regimes Based on Wall-Pressure Analysis

The present study is developed within the general framework of marine structure design of lifting bodies, operating in transient regimes. The study concerns the experimental and numerical investigations of time-space distribution of the wall pressure field on a NACA66 hydrofoil in forced ramping motion. The angle of incidence varies from 0° to 15° beyond stall. Experiments in a hydrodynamic tunnel and corresponding RANSE based code calculations are carried out for various pitching velocities. Transducers are located along the chord of the hydrofoil. The numerical approach is conducted in turbulent regime using recent laminar to turbulent transition model. Global coefficients are analyzed in order to quantify the transient effects. The comparison of calculated to measured local wall pressures on the suction side leads to the identification of the effect of pitching velocity on hydrodynamic loading. Moreover, the consequences of pressure fluctuations induced by the laminar to turbulent transition are highlighted. The evolutions of transition, laminar bubble and leading and trailing edge detachments are discussed in the context of naval applications.