Effect of Ground Board Boundary Layer on Air Cushion Vehicle Wind Tunnel Tests

摘要

Forward speed tests were performed on an Air Cushion Vehicle in the subsonic wind tunnel using a fixed ground board. The effect of the ground board boundary layer on the reactions of the vehicle was determined by comparing the test results with previous tethered flight tests conducted in the circular track facility. Comparisons with similar reported tests were made to extend these test results. The results did not indicate any noticeable differences between the wind tunnel and circular track results. Analysis showed that differences begin to appear as the forward speed increases and curves the leading edge jet backwards. The magnitude of the boundary layer effect on the vehicle reactions is shown to depend on the testing technique used. The suitability of low priced model aircraft engines for low budget powered model testing is demonstrated. (Author)