Numerical Determination of Indicial Lift of a Two-Dimensional Sinking Airfoil at Subsonic Mach Numbers From Oscillatory Lift Coefficients With Calculations for Mach Number 0.7

Abstract

The reciprocal equations for relating the incompressible circulatory indicial lift to the lift due to harmonic oscillations have been modified to include the noncirculatory lift associated with apparent-mass effects. Although the apparent-mass effects are impulsive in nature in incompressible flow, the lift due to apparent-mass effects in compressible flow is a time-dependent function. The corresponding reciprocal equations for the total compressible lift are given. By use of the reciprocal equations for compressible flow, the indicial lift and moment functions due to an airfoil's experiencing a sudden acquisition of vertical velocity are determined numerically for Mach number 0.7. Lack of sufficient flutter coefficients prevents the calculation of these functions at other Mach numbers.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1951
Accession Number
ADA380451

Entities

People

  • Bernard Mazelsky

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Accuracy
  • Acquisition
  • Aeronautical Laboratories
  • Air Force
  • Airfoils
  • Coefficients
  • Compressible Flow
  • Compressive Properties
  • Dynamic Loads
  • Equations
  • Flow
  • Frequency
  • Gust Loads
  • Incompressible Flow
  • Mach Number
  • Steady State
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Fluid Mechanics and Fluid Dynamics.