Computing Induced Velocity Perturbations due to a Helicopter Fuselage in a Free Stream

Abstract

The velocity field of a representative helicopter fuselage in a free stream is computed. Perturbation velocities due to the fuselage are computed in a plane above the location of the helicopter rotor (rotor removed). The velocity perturbations computed by a source-panel model of the fuselage are compared with experimental measurements taken with a laser velocimeter. Three paneled fuselage models are studied: fuselage shape, fuselage shape with hub shape, and a body of revolution. The velocity perturbations computed for both fuselage shape models agree well with the measured velocity field except in the close vicinity of the rotor hub. In the hub region, without knowing the extent of separation, modeling of the effective source shape is difficult. The effects of the fuselage perturbations are not well-predicted with a simplified ellipsoid fuselage. The velocity perturbations due to the fuselage at the plane of the measurements have magnitudes of less than 8 percent of free-stream velocity. The velocity perturbations computed by the panel method are tabulated for the same locations at which previously reported rotor-inflow velocity measurements were made. Keywords: Helicopter fuselage: Rotor inflow: Source panel: Laser velocimeter.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1989
Accession Number
ADA210262

Entities

People

  • John D. Berry
  • Susan L. Althoff

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Accuracy
  • Airframes
  • Computational Fluid Dynamics
  • Computer Programs
  • Dew Point
  • Dynamic Pressure
  • Equations
  • Far Field
  • Flow Fields
  • Fluid Dynamics
  • Geometry
  • Helicopter Rotors
  • Laser Velocimeters
  • Measurement
  • Near Field
  • Plastic Explosives
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Aerospace Engineering
  • Fluid Dynamics.
  • Fluid Mechanics and Fluid Dynamics.

Technology Areas

  • Directed Energy