An experimental study to stabilize the distribution of surface flow velocities in a circulating water tunnel for resistance and self-propulsion test of autonomous underwater vehicle

This study aimed to validate the speed at the boundary layer in the water circulating channel and examined the effect of surface flow acceleration. When the surface speed accelerator is operated, the distribution of the flow rate increases by 5-10% from the set flow rate near the inlet. The surface flow speed gradually decreases as it moves away from the inlet and reaches the desired flow speed.

Therefore, adjusting the rate when conducting an experiment near the water-air surface in the water circulation was necessary. The flow velocity distribution at the boundary's vertical and horizontal directions is a significant parameter. A specialized system was designed and installed to accelerate the surface flow rate according to the inflow velocity. The added inertial force at the surface was found to have an effect up to a depth of more than 30 cm. It plans to make the acceleration effect of the flow speed through the particle image velocimetry and laser doppler velocimeter.