Effects of Forward Speed on Cushion Pressure Characteristics of ACV's

Abstract

The purpose of this paper is to present a detailed study of the forward speed effect to the cushion pressure characteristics of ACV's, from the both theoretical and experimental points of view.
The experiments are performed for a two-dimensional rectangular-shaped model in a wind tunnel with a moving ground, and theoretical calculations are carried out by using the momentum theory in the case of the subcritical and supercritical forward speed, The main conclusion are summarized as follows:
1) Experimental results were predicted by the present momentum theory.
2) The cushion pressure in the diffusion region is much less than that in channel flow region.
3) However, even in the channel flow region, the pressure slightly rise up with the downstream. This is caused by the friction-pump effect of the moving ground.
4) The rear ambient pressure affects into the cushion pressure remarkably, that is, as this pressure increase negatively, the cushion pressure is reduced, with the negative increase of the rear ambient pressure.