An experimental investigation of a fighter aircraft model at high angles of attack

Abstract

A low speed wind tunnel investigation was conducted to examine the aerodynamic characteristics of the flowfield around a three percent scale YF-17 lightweight fighter prototype model at high angles of attack using flow visualization and force and moment measurements. Smoke filaments, injected into the wind tunnel test section, were illuminated by a laser sheet to highlight flow phenomena about the model. Force and moment measurements were made using a precision six-component strain gage balance. The investigation marked the first attempt at qualitative flow analysis using the laser sheet flow visualization system recently installed in the Naval Postgraduate School low speed wind tunnel facility. The investigation was undertaken to specifically identify flow phenomena and/or regions of interest that may have bearing on the design and performance of supermaneuverable aircraft. The data indicate a good correlation between the observed flow phenomena and force and moment measurements at various angles of attack, thus establishing the credibility of such experimental investigations for high angle of attack aerodynamic research.