Investigations of an airfoil at low Reynolds number conditions

C. Brehm, S. Mack, A. Gross, Hermann F Fasel

Research output: Chapter in Book/Report/Conference proceedingConference contribution

30 Citations (Scopus)

Abstract

The low-Reynolds number aerodynamics of airfoils that were designed for higher Reynolds numbers can be surprisingly different from what one might expect. The intricate interplay of separation and transition can substantially affect airfoil performance at lower than de-sign Reynolds number. We employed computational fluid dynamics for investigating the natural (uncontrolled) flow field around the NACA 643 - 618 airfoil at a chord Reynolds number of 64,000 for different angles of attack. Airfoil performance at moderate angles of attack is reduced considerably due to a massive trailing edge separation. At high angles of attack a leading edge separation bubble is formed which was found to transition the flow and reduce the trailing edge separation resulting in a lift recovery. We also investigated open-loop control by blowing and suction through a slot. We found that by exploiting hydrodynamic instability of the baseflow the control could be made more effective. The final objective is to develop closed-loop controllers for airfoils that will help recover the full size performance at lower model Reynolds-number conditions with minimal control effort.

Original languageEnglish (US)
Title of host publication4th AIAA Flow Control Conference
StatePublished - 2008
Event4th AIAA Flow Control Conference - Seattle, WA, United States
Duration: Jun 23 2008Jun 26 2008

Other

Other4th AIAA Flow Control Conference
CountryUnited States
CitySeattle, WA
Period6/23/086/26/08

Fingerprint

Airfoils
Reynolds number
Angle of attack
Blow molding
Flow fields
Aerodynamics
Computational fluid dynamics
Hydrodynamics
Recovery
Controllers

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes
  • Aerospace Engineering
  • Control and Systems Engineering

Cite this

Brehm, C., Mack, S., Gross, A., & Fasel, H. F. (2008). Investigations of an airfoil at low Reynolds number conditions. In 4th AIAA Flow Control Conference [2008-3765]

Investigations of an airfoil at low Reynolds number conditions. / Brehm, C.; Mack, S.; Gross, A.; Fasel, Hermann F.

4th AIAA Flow Control Conference. 2008. 2008-3765.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Brehm, C, Mack, S, Gross, A & Fasel, HF 2008, Investigations of an airfoil at low Reynolds number conditions. in 4th AIAA Flow Control Conference., 2008-3765, 4th AIAA Flow Control Conference, Seattle, WA, United States, 6/23/08.
Brehm C, Mack S, Gross A, Fasel HF. Investigations of an airfoil at low Reynolds number conditions. In 4th AIAA Flow Control Conference. 2008. 2008-3765
Brehm, C. ; Mack, S. ; Gross, A. ; Fasel, Hermann F. / Investigations of an airfoil at low Reynolds number conditions. 4th AIAA Flow Control Conference. 2008.
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