Sperotto de Quadros, Régis (2009)
Numerical Optimization of Boundary-Layer Control using Dielectric Barrier Discharge Plasma Actuators.
Technische Universität Darmstadt
Ph.D. Thesis, Primary publication
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Item Type: | Ph.D. Thesis | ||||
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Type of entry: | Primary publication | ||||
Title: | Numerical Optimization of Boundary-Layer Control using Dielectric Barrier Discharge Plasma Actuators | ||||
Language: | English | ||||
Referees: | Tropea, Dr.Ing Cameron | ||||
Date: | 27 July 2009 | ||||
Place of Publication: | Darmstadt | ||||
Date of oral examination: | 1 July 2009 | ||||
Abstract: | A numerical investigation of active wave cancellation, using a plasma actuator in both continuous and pulsed operation modes, was carried out for a flat-plate boundary layer with an adverse pressure gradient at low Reynolds number. Pulsing was achieved by rectangular and sinusoidal modulation of the high-frequency plasma excitation voltage. A closed-loop control was developed and implemented using Large-Eddy Simulations into a CFD code (FASTEST). With this feed-back control algorithm it was found that the control can be limited to two operating parameters in order to significantly reduce Tollmien-Schlichting waves (TS-waves). The feed-back control algorithm was validated using two existing optimization methods which were also implemented in the code. The first method finds a local minimum of a function with several variables using a pattern search technique that compares function values at the three vertices of a triangle. The second method, known as the trust-region method, is based on quadratic models for derivative-free minimization. It was found that the developed feed-back control works efficiently and can be used to determine the optimum operating parameters of the plasma actuator for cancellation of TS-waves. The amplitude reduction of TS-waves is of interest since it allows for a delay of laminar-to-turbulent transition in the boundary layer, resulting in significant drag reduction. |
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URN: | urn:nbn:de:tuda-tuprints-18619 | ||||
Classification DDC: | 500 Science and mathematics > 500 Science 500 Science and mathematics > 510 Mathematics |
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Divisions: | 16 Department of Mechanical Engineering > Fluid Mechanics and Aerodynamics (SLA) | ||||
Date Deposited: | 28 Jul 2009 08:29 | ||||
Last Modified: | 07 Dec 2012 11:55 | ||||
URI: | https://tuprints.ulb.tu-darmstadt.de/id/eprint/1861 | ||||
PPN: | 214264300 | ||||
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