IMPACT OF SOLID BOUNDARIES AND VISCOSITY OF THE MEDIUM ON THE CONTRIBUTION OF THE INERTIAL AND VORTEX COMPONENTS OF THE NORMAL FORCE OF A ROTATING PLATE. PART 1

Abstract

Within the framework of the improved method of discrete vortices, generalized for viscous media, a method was developed for determining the contribution of forces of inertial, vortex and circulation nature to the normal force of a plate moving in a stationary viscous boundless medium according to an arbitrary law, in the presence of a wall and in a channel. The developed method was tested for the case of instantaneous angular start of the plate and subsequent constant angular speed of rotation (Wagner's problem) in a viscous boundless medium, in the presence of a wall and in a channel, in laminar and turbulent modes. The inertial-vortical nature of the normal force of the plate (with the dominance of inertial forces) was confirmed, which rotates after an instantaneous start with the separation of the flow from both its edges, regardless of the presence of solid boundaries and laminar or turbulent flow regimes. It has been clarified, that in the case of the laminar regime, the influence of the presence of the wall on the reduced inertial component of the normal force of the plate is insignificant, but the influence of the channel leads to a faster departure of the laminar vortex from the front edge of the plate, which leads to a gradual increase in the contribution of the inertial component of the normal force of the plate up to 100% and more at the end of rotation plates. Approximately the same happens in the case of the absence of solid boundaries, when a turbulent vortex of a larger size and intensity than the corresponding laminar one moves away from the leading edge of the plate.