Pneumatic Turbulators - A Device for Drag Reduction at Reynolds Numbers below 5,000,000

Abstract

At Reynolds numbers below 5 million, airfoils are affected by laminar separation bubbles which, in many cases, considerably increase the drag. By blowing air from a row of orifices at the beginning of the laminar separation bubble, the bubble can be prevented and the drag can be reduced substantially. This device is called pneumatic turbulator. Free-stream total pressure is sufficient to provide the turbulator bleed air. The additional drag caused by the bleed air and the air jets is negligible. The low drag Reynolds number range of laminar airfoils can be extended by using pneumatic turbulators.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1984
Accession Number
ADP004069

Entities

People

  • A. Quast
  • K. H. Horstmann
  • L. M. M. Boermans

Organizations

  • Delft University of Technology

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Aircrafts
  • Airfoils
  • Airframes
  • Boundary Layer
  • Boundary Layer Control
  • Drag Reduction
  • Fluid Dynamics
  • Free Flight
  • Gliders
  • Laminar Boundary Layer
  • Measurement
  • Pressure Distribution
  • Reynolds Number
  • Test Facilities
  • Turbulent Boundary Layer
  • Turbulent Flow
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Combustion and Flow Dynamics.