Self-adaptive closed-loop control of low-reynolds number laminar separation

A. Gross, H. F. Fasel

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

6 Scopus citations


Closed-loop control of laminar separation was investigated numerically for a low-pressure turbine blade and an airfoil at relatively low operating Reynolds-numbers. Open-loop investigations show that within a certain frequency range disturbances are amplified. This can be exploited for making the control more effective. The amplification is attributed to a hydrodynamic instability of the base flow. A simple closed-loop controller, where a downstream pressure signal is fed back to an upstream actuator, is shown to be as effective as an optimized open-loop controller. The simple closed-loop controller can be improved by continuously adjusting the controller parameters during the run time of the simulation using a minimization algorithm that minimizes a desired objective such as drag over lift and control effort. This allows for an optimization of the gain and phase of the feedback resulting in a better "synchronization" or coupling of the actuation and the flow dynamics.

Original languageEnglish (US)
Title of host publicationCollection of Technical Papers - 25th AIAA Applied Aerodynamics Conference, 2007
PublisherAmerican Institute of Aeronautics and Astronautics Inc.
Number of pages12
ISBN (Print)1563478986, 9781563478987
StatePublished - 2007
Event25th AIAA Applied Aerodynamics Conference, 2007 - Miami, FL, United States
Duration: Jun 25 2007Jun 28 2007

Publication series

NameCollection of Technical Papers - AIAA Applied Aerodynamics Conference
ISSN (Print)1048-5953


Other25th AIAA Applied Aerodynamics Conference, 2007
Country/TerritoryUnited States
CityMiami, FL

ASJC Scopus subject areas

  • Engineering(all)


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