WIND TUNNEL TESTS OF FULL-SCALE ROTORS OPERATING AT HIGH ADVANCING TIP MACH NUMBERS AND ADVANCE RATIOS

Abstract

Tested were: (1) production UH-1D (NACA 0012 profile) 48-foot- diameter blades, (2) modified UH-1D blades reduced in thickness at the tip, and (3) UH-1D blades reduced in diameter to 34 feet. The production blades were evaluated at Mach numbers up to 0.95, the thin-tipped blades to Mach 1.025, and the 34-foot rotor to advance ratios of 0.79. The production and thin-tipped blades are compared to show the compressibility effects. At higher tip Mach numbers, a significant reduction in power required was obtained with the thin- tipped blades. Additionally, the state of the art of calculating rotorcraft performance at high tip speeds and advance ratio is reviewed, and limited experimental data obtained with special boundary layer instrumentation installed at the 3/4 radius and surface pressure instrumentation installed near the blade tip are presented.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1968
Accession Number
AD0674188

Entities

People

  • James F. Van Wyckhouse
  • Watson H. Tanner

Organizations

  • Bell Flight

Tags

Communities of Interest

  • Air Platforms
  • Cyber
  • Human Systems
  • Space

DTIC Thesaurus Topics

  • Actuators
  • Aircrafts
  • Army Aviation
  • Boundary Layer
  • Helicopter Rotors
  • Helicopters
  • Mach Number
  • Measurement
  • Pressure Distribution
  • Pressure Measurement
  • Resonant Frequency
  • Rotary Wing Aircraft
  • Test Equipment
  • Test Facilities
  • Transducers
  • Wind Tunnel Tests
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Aerodynamics.