Abstract
In this project we aim at deriving and testing a control algorithm based on the adjoint compressible boundary region equa- tions, which are obtained in the assumption that the streamwise wavenumber of the disturbances is much smaller the the crossflow wavenumbers. The goal is to achieve optimum control of stream-wise vortices, which is expected to result in a re- duction of vortex energy and ultimately delay the transition from laminar to turbulent flow. Flow instabilities are introduced either through roughness elements equally separated in the span-wise direction or via free-stream disturbances. The com- pressible Navier-Stokes equations are reduced to the boundary region equations (BRE) in a high Reynolds number asymptotic framework, wherein the stream-wise wavelengths of the disturbances are assumed to be much larger than the span-wise and wall-normal counterparts. Lagrange multipliers are utilized to derive the adjoint compressible boundary region equations, by transforming the constrained optimization problem into its unconstrained form. In the implemented optimal control strategy, the wall transpiration velocity represents the control variable whereas the wall shear stress or the vortex energy designates the cost functional.
Original language | English |
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Publication status | Published - 16 Aug 2021 |
Event | International Conference on Flow Dynamics - University of Tohoku, Sendai, Japan Duration: 27 Oct 2021 → 29 Oct 2021 https://www.ifs.tohoku.ac.jp/icfd2021/ |
Conference
Conference | International Conference on Flow Dynamics |
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Abbreviated title | ICFD-18 |
Country/Territory | Japan |
City | Sendai |
Period | 27/10/21 → 29/10/21 |
Internet address |
Keywords
- active control
- boundary region equations
- Computational Fluid Dynamics
- Transition modeling