The impact of forebody geometries at high-angle-of-attack with forebody tangential blowing

摘要

This paper presents a study of the impact of forebody nose geometry on the lateral-directional dynamics of aircraft at high angle of attack with and without forebody tangential blowing (FTB). ^It is shown that the vortical flow over a sharp-tipped forebody is asymmetric, generating roll and yaw moments on the vehicle that are not highly repeatable. ^The introduction of a slightly rounded forebody is found to attenuate flow asymmetry and enhance repeatability. ^The effectiveness of FTB with this forebody is also improved. ^Results from rounded nose cones of various radii are presented for comparison. ^They show that changing the radius of the nose tip does not significantly affect roll and yaw moment behavior as a function of roll and yaw angles and the amount of blowing. ^The experimental apparatus used in this study is described, and static measurements of the aerodynamic loads for various roll and yaw angles and blowing amounts are presented. ^The apparatus consists of an FTB-equipped wind tunnel model which has 2 DOFs, roll, and yaw. ^The model is a wing-body combination with slots on the forebody for tangential blowing, and is nominally set at 45-deg angle of attack. ^(Author)