Aerodynamic test and analysis of wrap-around fins at supersonic Mach numbers utilizing design of experiments

Abstract

Cxb =body axial force coefficient at zero angle of The aerodynamics of wrap-around fins (WAFs) are influenced by various factors, including Mach number, Icngth-to-diameter (LD) ratio, fin sweep angle, fin root chord length, and fin thickness. This paper presents the rcsults of an investigation into the effects of these factors on WAFs at supersonic Mach numbers. This effort was conducted to furthcr define WAF flight characteristics. The design of experiments (DOE) test approach was used to detcrmine the feasibility of DOE in extracting aerodynamic coefficients from spark range testing, as well as to provide a measure of cost savings. The results of the free flight data reduction and predictions arc summarized and compared to the DOE model and to engineering code predictions. These results show the effect of each factor on the tin axial force coefficient, fin normal force, and total pitching moment derivative coefficients. In addition, an analysis was completed for thc roll and side force. The results of this analysis show good agrcement with the DOE modcl and engineering prediction codes. This study also shows that DOE methodology is an efficient way to predict aerodynamic coefficients for spark range testing. -i