Aero-Hydrodynamic Aspects of Power-augmented Ram Wings

Abstract

The subject of this article is the two-dimensional interaction of air and water flows under a power-augmented ram wing. The extreme ground effect theory is applied for the air flow, whereas the water flow is treated with a linearized model based on a method of hydrodynamic singularities. Calculated aerodynamic characteristics of power-augmented ram platforms and water surface deformations at moderate and high Froude numbers are presented for a horizontal plate with a flap, a trimmed plate without a flap, and an S-shaped profile. Additionally, plates in contact with water are modeled. The transition from airborne to waterborne states is accompanied by drastic variations of the lift and center of pressure. It is found that solutions can be nonunique when the plate trailing edge is very close to the water surface.