Computational Study of Afterbody Effects for the Joint Direct Attack Munition (JDAM)

Abstract

Computational analysis of a JDAM in the M(infinity) = 0.9 to 1.4 flow regime determined the effect of changes to the store afterbody and support sting on store loads. The computational results compared well to three sets of wind tunnel data. Accuracy requirements necessitated both that the store geometry be modeled with exceptional detail, and that the Navier-Stokes equations with the Nichols' k-Epsilon turbulence model be employed. Comparisons to measured data showed excellent agreement with aerodynamic load increments and also with the absolute values of the loads. Analysis using a wall function model for the boundary layer also compared well with data. The comparisons established a sufficient level of confidence in the numerical model as to allow its use in determining the forces and moments free of support effects at the flight Reynolds number.

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Document Details

Document Type
Technical Report
Publication Date
Jun 18, 1998
Accession Number
ADA370994

Entities

People

  • C. T. Bangasser
  • J. H. Fox
  • T. L. Donegan

Organizations

  • Arnold Engineering Development Complex

Tags

Communities of Interest

  • Counter IED
  • Human Systems
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aerodynamic Characteristics
  • Aeronautics
  • Air Force
  • Boundary Layer
  • Computational Fluid Dynamics
  • Computations
  • Dynamic Pressure
  • Engineering
  • Equations
  • Euler Equations
  • Free Stream
  • Geometry
  • Layers
  • Mach Number
  • Reynolds Number
  • Satellite Guided Weapons
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Computational Modeling and Simulation
  • Fluid Mechanics and Fluid Dynamics.