Multivariable closed-loop control of the reattachment length downstream of a backward-facing step
| Authors: | Henning Lars, Berlin University of Technology, Germany
King Rudibert, Berlin University of Technology, Germany |
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| Topic: | 7.3 Aerospace |
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| Session: | Aerospace Control |
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| Keywords: | backward-facing step, black-box model, flow control, multivariable control, reattachment length, robust control |
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Abstract
Active control of separated flows has become a major challenge in recent years. Whereas most of the work published so far is based on simulation studies this paper gives an example of a successful application of a multivariable closed-loop flow control in wind tunnel experiments. A robust H∞-controller is used to control the spanwise reattachment length downstream of a benchmark problem, a so-called backward-facing step. The synthesis of the controller is based on a family of identified linear black-box models. To reduce the conservatism of this approach, a nonlinear static precompensation is included. Tracking performance and disturbance rejection of the controller are tested in wind tunnel experiments.
