Ground effect on a cropped slender reverse delta wing with anhedral and Gurney flaplike side-edge strips

摘要

The ground effect on the aerodynamic coefficients of a cropped slender reverse delta wing equipped with anhedral and Gurney flaplike side-edge strips was investigated experimentally at Re = 3.82 x 10(5). In a free stream, the 30% cropping was found to cause a minor reduction in lift C-L and drag C-D coefficients but a promoted stall compared to the noncropped wing. The anhedral caused further C-L decrease and C-D increase. Meanwhile, the application of side-edge strips produced a significantly increased C-L and C-D with a minor change to the C-L/C-D ratio as compared to the baseline wing. In ground effect, the cropped wing was, however, found to generate more lift compared to the noncropped wing as the ground was approached. The joint anhedral and SES produced a great increment in both C-L and C-D but a virtually unchanged C-L/C-D ratio compared to their outside ground effect counterparts. The larger the side-edge strips' height the larger the increase in C-L. In short, the cropping led to a weight reduction while the addition of anhedral and SES produced a large lift augmentation of the Lippisch-type wing-in-ground effect craft.