Body-fin Aerodynamic Interference For Low Aspect Ratio Missiles


The supersonic missile interference factor, KB(w), is a measure of the change in normal force on the body due to the presence of the fins. An Euler code is used to numerically evaluate KB(w)for low aspect ratio missiles at Mach numbers from 3 to 4 and angles of attack up to 20 deg. Missile fin span to body radius ratios (S/R) range from 1.3 to 2.0, such that aspect ratios vary from 0.05 to 4. Afterbody length effects are also considered. Euler results compare well with available experimental data. Body pressure isobars show that shock and expansion waves from the fin interact with the body and strongly contribute to KB(w)thus, Euler predictions differ significantly from those of slender body theory (SBT). As aspect ratio decreases from 4 to 0.05, KB(w)increases to a maximum value and then l) decreases for small values of angle of attack and 2) remains fairly constant for high values of angle of attack. The aspect ratio for the maximum KB(w)depends on S/R. Generally KB(w)increases in magnitude and its maximum value shifts to lower aspect ratios when Mach number increases. KB(w)values are presented graphically for use in conceptual and preliminary design.


Mechanical and Aerospace Engineering

Document Type

Article - Conference proceedings

Document Version


File Type





© 2023 American Institute of Aeronautics and Astronautics, All rights reserved.

Publication Date

01 Jan 1992