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Parameters Defining Active Flow Control

Oshima, Emile and Gharib, Morteza and Reichert, Johannes and Wygnanski, Israel (2021) Parameters Defining Active Flow Control. In: AIAA Aviation 2021 Forum. American Institute of Aeronautics and Astronautics , Reston, VA, Art. No. 2021-2855. ISBN 978-1-62410-610-1.

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There is a conceptual difference between Boundary Layer Control (BLC) and Active Flow Control (AFC). The former aims to compensate for frictional losses in the boundary layer, while the latter seeks to exploit instabilities in the flow to alter its character. The momentum coefficient Cμ has been the parameter of choice for energizing the boundary layer and enhancing the circulation by blowing. While it has proven useful in cataloging some data, it is not a universally valid single parameter describing the complex flow over wings. Furthermore, the jet velocity and density required for its calculation are difficult to measure in situ, necessitating unrealistic assumptions or extensive calibrations. The best quantity to be used is one that defines the energy requirements of the entire AFC system while realizing its lack of uniqueness. Experimental investigations on a thick flapped airfoil and a simple swept wing demonstrate that such a quantity is more suitable for design purposes because it shifts the perspective from detailed jet flow to system needs. Although this figure-of-merit approach black boxes flow interaction details between the jet and the freestream, system-based coefficients can still provide various physical insights in their capacity as cataloguing parameters.

Item Type:Book Section
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Gharib, Morteza0000-0003-0754-4193
Additional Information:© 2021 by the American Institute of Aeronautics and Astronautics.
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AIAA Paper2021-2855
Record Number:CaltechAUTHORS:20210901-145701023
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Official Citation:Emile Oshima, Morteza Gharib, Johannes Reichert and Israel Wygnanski. "Parameters Defining Active Flow Control," AIAA 2021-2855. AIAA AVIATION 2021 FORUM. August 2021; DOI: 10.2514/6.2021-2855
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:110681
Deposited By: Tony Diaz
Deposited On:01 Sep 2021 18:01
Last Modified:01 Sep 2021 18:01

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