Reducing poorly streamlined body water resistance by using active boundary layer control devices

Abstract

It is proposed to install on the wetted surface of the poorly streamlined body: on one a profiled recess, and on the second step. The first device changes the pressure distribution on the surface of the selected object. In the middle recess, a vortex motion is created, in the middle of which the pressure is lowered, which makes it possible to reduce the thickness of the boundary layer. The main purpose of the second device is to reduce the suction effect of water during acceleration of the object. Thus, the resistance force decreases, which means that it is much easier and faster to pick up speed and maintain it for a long time. After studying two methods of reducing resistance, it is proposed to evaluate the effectiveness and the prospect of using the above methods simultaneously with the air lubrication method. The Air Lubrication technology is based on blowing air bubbles out under the hull of the vessel. The air bubble distribution across the hull surface reduces the resistance creating a sublayer between the body of the object and water. These studies were conducted in the Flow Vision software package to obtain visualization and calculations, which confirm that the use of the proposed methods makes it possible to reduce the resistance of the body when it is moved in a liquid.