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arXiv · 1402.1746

Adaptive and model-based control theory applied to convectively unstable flows

N. Fabbiane·O. Semeraro·S. Bagheri·D. S. Henningson
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Abstract

Research on active control for the delay of laminar-turbulent transition in boundary layers has made a significant progress in the last two decades, but the employed strategies have been many and dispersed. Using one framework, we review model-based techniques, such as linear-quadratic regulators, and model-free adaptive methods, such as least-mean square filters. The former are supported by a elegant and powerful theoretical basis, whereas the latter may provide a more practical approach in the presence of complex disturbance environments, that are difficult to model. We compare the methods with a particular focus on efficiency, practicability and robustness to uncertainties. Each step is exemplified on the one-dimensional linearized Kuramoto-Sivashinsky equation, that shows many similarities with the initial linear stages of the transition process of the flow over a flat plate. Also, the source code for the examples are provided.

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N. Fabbiane, O. Semeraro, S. Bagheri, D. S. Henningson. 2014-02-06. Adaptive and model-based control theory applied to convectively unstable flows. https://arxiv.org/abs/1402.1746

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