Numerical analysis of righting moment for heeling of a wing with heel angles in the surface effect

A wing-in-surface-effect-ship (WISES) is a high-speed transportation system that utilizes the enhanced lift-to-drag ratio which occurs in the proximity of the water surface. Unlike conventional aircraft and ships, a WISES experiences a righting moment against heeling from the surface. In this study, we analyzed the flow around a wing that has heel angles in the surface effect using Reynolds-averaged Navier–Stokes (RaNS) simulations and experiments. We compared our numerical results with the measurements obtained in the wind tunnel tests to confirm the validity of the computational approach under several conditions. To detect the righting moment for heeling without the effect of a boundary layer, we implemented a towing tank experiment and compared the results. In the towing tank experiment, we towed a wing model above flat plates in the water. Our results showed that a righting moment is generated for a wing that has heel angles in the surface effect. The righting moment is not proportional to the heel angle. In addition, the moment increases with decrease of the trailing edge altitude. Furthermore, we found that the addition of endplates enhances the righting moment.