Investigation of Factors Affecting the Wind Tunnel Measurements of Carriage-Position Airloads on External Store Models at Transonic Mach Numbers.

摘要

A wind tunnel test was conducted to investigate the factors affecting the M-117and BLU-1C/B (finned and unfinned) store carriage-position airloads beneath the wing of a 0.05-scale A-7D aircraft. The investigation included:store afterbody modifications,the presence of stings of various diameters and shapes,misalignment of store relative to its carriage position,variations of aircraft yaw attitude,and various store carriage positions on the multiple ejector rack (MER). The rigid loads technique,which simulated the captive trajectory system (CTS) technique,was used to measure carriage-position airloads and the results compared to the CTS results. The test was conducted at Mach number 0.7, 0.9,and 1.05with the aircraft angle of attack ranging from -2to 12deg. The results indicated that the M-117carriage-position airloads were the most sensitive to any of the factors and the unfinned BLU-1C/B the least sensitive to all the factors investigated. The carriage-position airloads were most sensitive to store afterbody modifications. Most of the effects were greater at Mach number 1.05.