Further Noise Measurements in a Slotted Cryogenic Wind Tunnel

Abstract

This Memorandum describes some noise measurements in a cryogenic wind tunnel with slotted walls at subsonic and transonic speeds. Pressure fluctuations were measured at three positions on the sidewall of the working section, the downstream end of the plenum chamber and near the inlet and outlet of the first diffuser. Analysis of the measurements suggest that the diffuser noise field can be represented by the superposition of monopole, dipole and quadrupole sources. The existence of these sources suggests that the diffuser flow may be separated for a significant portion of its length, either because of poor entry conditions or the presence of the model support strut. As expected, a small model at a small angle of incidence generally has a small effect on the noise measurements in the working section. Recommendations are made for further research.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1990
Accession Number
ADA233572

Entities

People

  • D. G. Mabey

Organizations

  • Royal Aircraft Establishment

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Angle Of Incidence
  • Aspect Ratio
  • Chambers
  • Diffusers
  • Equations
  • Far Field
  • Flow
  • Flow Visualization
  • Fluid Flow
  • Foreign Languages
  • Free Stream
  • Frequency
  • Instrumentation
  • Mach Number
  • Measurement
  • Plenum Chambers
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Acoustics.
  • Aerodynamics.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.