Computational Investigation of Roll Damping for Missile Configurations

Abstract

Results from computational fluid dynamics (CFD) predictions of roll damping on three elementary missile configurations are presented in this work. RavenCFD, a threedimensional unstructured-grid Navier-Stokes solver, is used in conjunction with a rigid body motion (RBM) capability and an embedded six-degree-of-freedom (6-DOF) solver to simulate both prescribed rolls and free-to-roll configurations.Several different methodologies are applied to both prescribed-roll and free-to-roll CFD calculations to obtain estimates of roll damping coefficient across a broad range of Mach numbers. In general, the computational results agree well with experimental roll-damping measurements across the range of Mach numbers and angles of attack considered. Nomenclatureα = Angle of attack ϕ = Roll angle C lp = Roll damping coefficient C l = Rolling moment coefficient d = Configuration base diameter I xx = Moment of inertia about roll axis M ∞ = Freestream Mach number U ∞ = Freestream velocity T ∞ = Freestream temperature p = Roll rate pd/2U ∞ = Nondimensional roll rate p ∞ = Freestream pressure q ∞ = Freestream dynamic pressure S = Configuration reference area

Comparison of Flow field in the proximity of A Single Planar & Wrap-around Fin

“…The fin drag comparison, between the planar and the wrap-around, showed that the WAFs had 10% higher value as that of the planar fins. In the past, numerous numerical studies (Bagheri, Pasandidehfard, & Tavakoli Sabour 2018;Li, Abbas, & Rui, 2015;Krishna, Surit, Kushari, & Ghosh, 2009;Eidell, Nance, McGowan, Carpenter, & Moore, 2012;Murman, 2007) have been performed on planar and wrap-around finned missiles which have used inviscid, viscid and turbulent flow conditions. However, most of these studies were performed on a complete missile body with four fins, these studies form the basis of implying turbulence modelling to the current model.…”