Accession Number : ADA323843

Title :   Computations of Supersonic Vortical Flows Around Ogive-Cylinders Using Central and Upwind Differences.

Descriptive Note : Final rept. 1 Jul 94-1 Mar 96,

Corporate Author : WRIGHT LAB WRIGHT-PATTERSON AFB OH

Personal Author(s) : Josyula, Eswar

PDF Url : ADA323843

Report Date : MAR 1997

Pagination or Media Count : 52

Abstract : This work is part of a cooperative research, development, test and evaluation program that brings scientists and engineers from various English-speaking countries together for collaborative studies to improve technology to solve technical problems. The current TTCP work project WTP-2 KTA 2-12, 'Application of CFD to the prediction of Missile Body Vortices' focuses on the ability of the three-dimensional Navier-Stokes equations to predict flowfields about high length-to-diameter bodies at moderate angles of attack (8 deg < a < 14 deg) for supersonic Mach numbers. This report documents this author's computational results for the five test cases. The five test cases are as follows. Mach 1.45 at a = 14 deg, Mach 1.8 at a = 14 deg, Mach 2.5 at a = 14 deg, Mach 3.5 at a = 8 deg, and Mach 3.5 at a = 14 deg. The experimental body is 13 diameters long with the diameter of the cylindrical afterbody of 3.7 inches. Laminar and turbulent computations are shown with comparisons to experimental data. The experimental validation data was provided by the Defence Research Agency (UK). The computations were performed with an existing Navier-Stokes code FDL3DI developed in the Wright Laboratory. The surface pressure and pitot pressure predictions matched with the experimental data reasonably well. The k-e turbulence model was found to be highly dissipative for capturing vortical flows. Local grid refinement was considered to be an important aspect of capturing the vortical flows accurately.

Descriptors :   *VORTICES, *COMPUTATIONAL FLUID DYNAMICS, *SUPERSONIC FLOW, *GUIDED MISSILE MODELS, AERODYNAMIC CONFIGURATIONS, TURBULENCE, TURBULENT FLOW, ANGLE OF ATTACK, FLOW FIELDS, MACH NUMBER, NAVIER STOKES EQUATIONS, FLOW SEPARATION, LAMINAR FLOW, PRESSURE DISTRIBUTION, REYNOLDS NUMBER, BOUNDARY LAYER FLOW, THREE DIMENSIONAL FLOW.

Subject Categories : Guided Missile Dynam, Config & Cntrl Surfaces
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE