Navier-Stokes Predictions of the Individual Components of the Pitch-Damping Coefficient Sum

Abstract

An approach for predicting the two individual aerodynamic damping coefficients that form the pitch-damping coefficient sum is presented. The coefficients are obtained using prescribed or forced motions that independently excite the two different angular rates that are associated with the two damping coefficients. A key feature of the approach is that steady flow fields are produced by the selected motions. Steady flow computational fluid dynamics approaches can be applied, allowing results to be obtained in a computationally efficient manner. Application of the technique is made to an axisymmetric projectile configuration. The predicted pitch-damping coefficient sum obtained by adding the individually determined coefficients is in excellent agreement with previous predictions of the pitch-damping coefficient sum and with experimental data. Additional validation of the approach is obtained through comparisons with prior results from numerical solutions of the nonlinear unsteady potential equation. The individual coefficients are also compared with slender body theory, and the results show similar trends though the slender body theory appears to underpredict the various coefficients.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 2004
Accession Number
ADA422328

Entities

People

  • Paul Weinacht

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Bodies
  • Boundary Layer
  • Computational Fluid Dynamics
  • Computational Science
  • Equations
  • Experimental Data
  • Flow
  • Flow Fields
  • Fluid Dynamics
  • Fluid Flow
  • Geometric Forms
  • Geometry
  • Slender Bodies
  • Steady Flow
  • Three Dimensional
  • Two Dimensional
  • Viscous Flow

Readers

  • Aerodynamics.
  • Approximation Theory.
  • Computational Fluid Dynamics (CFD)