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.…”

Numerical Investigation of Static and Dynamic Aerodynamic Characteristics for a Guided Projectile with Fin Slot

“…G. Mikhail et al calculated and analyzed "Copperhead" homing projectile aerodynamic characteristics using aerodynamic prediction codes [8] . With the development of CFD (computational fluid dynamic) technology, more and more people are using commercial CFD software for projectile aerodynamic analysis and calculation [9][10][11][12][13], however, less calculation and analysis of the aerodynamic characteristics change caused by the fin slot. In particular, calculating the dynamic derivatives and analysis the impact of changes in the fin slot width aerodynamics also is less.…”