Buffet response of a hammerhead launch vehicle wind-tunnel model

Abstract

A wind-tunnel test of a l/10th-scale Atlas-Centaur I launch vehicle model was conducted in the NASA Langley Transonic Dynamics Tunnel. The model was aeroelastically scaled to simulate flight bending modes using a partial mode technique. Several payload fairing configurations were tested at various angles of attack. No aeroelastic instabilities were found, and each configuration was generally more sensitive to Mach number variations than changes in angle of attack. Small length-to-diameter fairing ratios produced changes in buffet response in the second bending mode configuration. Additional testing was performed with vertical rods attached to the sting support to reduce the effects of mechanical vibration induced through the facility. The first flight of the Atlas-Centaur I vehicle successfully occurred on July 25, 1990, and the flight response was found to be well within the 3a level of the wind-tunnel data.