A Wind Tunnel Investigation of a Small-Scale Tiltrotor Model in Descending Flight

Abstract

A small-scale tiltrotor model was tested in the 7- by 10-foot Wind Tunnel at NASA Ames Research Center, with the goal of better understanding Vortex Ring State (VRS) effects on tiltrotor aircraft. Test objectives were to obtain performance data of a tiltrotor model over a wide range of descent conditions, to explore the effects of sideslip at these descent conditions, and to investigate the validity of using a single-rotor with a physical image plane to simulate dualrotor performance characteristics. The model consisted of a pair of 2-bladed teetering rotors with untwisted, 11.125-inch diameter, rectangular planform blades. Model configuration variations included a dual-rotor, an isolated-rotor, and a single-rotor with a physical image plane. Rotor performance data were obtained for the dual-rotor configuration operating over a wide range of descent and sideslip conditions. Isolated-rotor and single-rotor with image plane configurations were tested over an abbreviated range of descent conditions. Results of this investigation are presented and show mean thrust reductions in the region of VRS for each model configuration. In comparison with the dual-rotor configuration, the isolated-rotor and single-rotor with image plane configurations produced thrust results similar in trend but different in magnitude.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2002
Accession Number
ADA480588

Entities

People

  • Anita I. Abrego
  • Kurtis R. Long

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aerial Warfare
  • Aerodynamic Characteristics
  • Aircrafts
  • Airframes
  • Coefficients
  • Data Acquisition
  • Flight
  • Helicopters
  • Rotary Wing Aircraft
  • Sideslip
  • Test And Evaluation
  • Tilt Rotor Aircraft
  • Tilt Wing Aircraft
  • Vehicles
  • Wind
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Aerospace Engineering