On the role of adaptivity for robust laminar flow control
2015 (English)In: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 767, R1-R12 p.Article in journal (Refereed) Published
In boundary layer flows, one may reduce skin friction drag by delaying the onset of laminar-to-turbulent transition via the attenuation of small-amplitude Tollmien Schlichting (TS) waves In this work, we use numerical simulations and experiments to compare the robustness of adaptive and model-based techniques for reducing the growth of two-dimensional TS disturbances. In numerical simulations, the optimal linear quadratic Gaussian (LQG) regulator shows the best performance under the conditions it was designed for However, it is found that the performance deteriorates linearly with the drift of the Reynolds number from its nominal value. As a result, an order-of-magnitude loss of performance is observed when applying the computation-based I.QG controller in wind-tunnel experiments In contrast, it is shown that the adaptive filtered-X least-mean-squares (FXLMS) algorithm is able to maintain an essentially constant performance for significant deviations of the nominal values of the disturbance amplitude and Reynolds number.
Place, publisher, year, edition, pages
2015. Vol. 767, R1-R12 p.
boundary layer control, flow control, instability control
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-154351DOI: 10.1017/jfm.2015.45ISI: 000349688900001ScopusID: 2-s2.0-84949117226OAI: oai:DiVA.org:kth-154351DiVA: diva2:756773
FunderSwedish Research Council Formas, VR-2012-4246, VR-2010-3910
Updated from Manuscript to Article. QC 201504882014-10-202014-10-202016-05-17Bibliographically approved