Active separation control for lifting surfaces at Low-Reynolds number operating conditions

A. Gross, W. Balzer, Hermann F Fasel

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

2 Citations (Scopus)

Abstract

The low-pressure turbine (LPT) stage is a common element of many modern jet engines. Its performance at cruise conditions is of great economical importance. Low-Reynolds number conditions and high blade loading can result in laminar separation from the suction side and performance degradation. For external aerodynamics problems, such as airfoils, low-Reynolds number conditions and large angles of attack can similarly lead to laminar flow separation, and in the worst case complete stall. Successful control of separation from lifting surfaces at such detrimental conditions promises significant savings in operating expenses and improved safety. We are employing computational fluid dynamics (CFD) for investigating passive and active flow control for lifting surfaces. Because of the many design parameters available for flow control strategies, such as the spacing and their dimensions, a trial and error optimization is ill-fated. It has been convincingly demonstrated in the past that through a deepened understanding of the underlying fundamental physical mechanisms the effectiveness of flow control can be greatly improved. In addition, an improved understanding will likely result in entirely new and innovative flow control devices and strategies. Using CFD we investigated separation control using vortex generator jets (VGJs) and harmonic blowing through a slot for a typical LPT blade. With pulsed and harmonic VGJs and for moderate blowing ratios as well as for harmonic blowing through a slot the generation of spanwise coherent structures that were amplified by the flow appeared to be the dominant mechanism for separation control. When the forcing amplitude was increased, the two-dimensional coherence was reduced and turbulent mixing appeared to become the more dominant mechanism. The hole spacing was found to have little effect as long as it was smaller than the length of the separated flow region.

Original languageEnglish (US)
Title of host publication2008 Proceedings of the Department of Defense High Performance Computing Modernization Program: Users Group Conference - Solving the Hard Problems
Pages9-17
Number of pages9
DOIs
StatePublished - 2008
Event2008 Department of Defense High Performance Computing Modernization Program: Users Group Conference - Solving the Hard Problems - Seattle, WA, United States
Duration: Jul 14 2007Jul 17 2007

Other

Other2008 Department of Defense High Performance Computing Modernization Program: Users Group Conference - Solving the Hard Problems
CountryUnited States
CitySeattle, WA
Period7/14/077/17/07

Fingerprint

Low Reynolds number
Flow Control
Flow control
Reynolds number
Blow molding
Harmonic
Computational Fluid Dynamics
Spacing
Vortex
Computational fluid dynamics
Vortex flow
Turbines
Generator
Turbulent Mixing
Flow Separation
Jet engines
Coherent Structures
Turbine Blade
Trial and error
Flow separation

ASJC Scopus subject areas

  • Computational Theory and Mathematics
  • Computer Science Applications
  • Theoretical Computer Science

Cite this

Gross, A., Balzer, W., & Fasel, H. F. (2008). Active separation control for lifting surfaces at Low-Reynolds number operating conditions. In 2008 Proceedings of the Department of Defense High Performance Computing Modernization Program: Users Group Conference - Solving the Hard Problems (pp. 9-17). [4755837] https://doi.org/10.1109/DoD.HPCMP.UGC.2008.23

Active separation control for lifting surfaces at Low-Reynolds number operating conditions. / Gross, A.; Balzer, W.; Fasel, Hermann F.

2008 Proceedings of the Department of Defense High Performance Computing Modernization Program: Users Group Conference - Solving the Hard Problems. 2008. p. 9-17 4755837.

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

Gross, A, Balzer, W & Fasel, HF 2008, Active separation control for lifting surfaces at Low-Reynolds number operating conditions. in 2008 Proceedings of the Department of Defense High Performance Computing Modernization Program: Users Group Conference - Solving the Hard Problems., 4755837, pp. 9-17, 2008 Department of Defense High Performance Computing Modernization Program: Users Group Conference - Solving the Hard Problems, Seattle, WA, United States, 7/14/07. https://doi.org/10.1109/DoD.HPCMP.UGC.2008.23
Gross A, Balzer W, Fasel HF. Active separation control for lifting surfaces at Low-Reynolds number operating conditions. In 2008 Proceedings of the Department of Defense High Performance Computing Modernization Program: Users Group Conference - Solving the Hard Problems. 2008. p. 9-17. 4755837 https://doi.org/10.1109/DoD.HPCMP.UGC.2008.23
Gross, A. ; Balzer, W. ; Fasel, Hermann F. / Active separation control for lifting surfaces at Low-Reynolds number operating conditions. 2008 Proceedings of the Department of Defense High Performance Computing Modernization Program: Users Group Conference - Solving the Hard Problems. 2008. pp. 9-17
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