### “Tutorial on Feedback Control of Flows, Part II: Diagnostics and Feedback Control of Mixing”

**Authors:**Ole M. Aamo and Thor I. Fossen,

**Affiliation:**NTNU, Department of Engineering Cybernetics

**Reference:**2002, Vol 23, No 4, pp. 275-298.

**Keywords:**Flow control, feedback, mixing

**Abstract:**Control of fluid flows span a wide variety of specialities. In Part II of this tutorial, we focus on diagnostics of mixing and the problem of enhancing mixing by boundary feedback control. Diagnostic tools from dynamical systems theory are presented that enable detection and quantification of chaotic transport in periodically perturbed systems. However, real systems are generally not periodic, and available measurements or simulations are finite in time. A method for quantifying mixing in finite-time velocity fields is discussed, and applied to data obtained from simulations of the 2D controlled channel flow. Mixing has traditionally been brought on by open-loop control strategies, such as stirring, jet injection or mixing valves. Applications of active feedback to mixing problems are scarce in the literature, but the idea is currently drawing attention from various research groups. Feedback laws for the purpose of mixing enhancement in 2D and 3D pipe flow are presented, and simulations show that they induce strong mixing.

PDF (2847 Kb) DOI: 10.4173/mic.2002.4.3

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**BibTeX:**

@article{MIC-2002-4-3,

title={{Tutorial on Feedback Control of Flows, Part II: Diagnostics and Feedback Control of Mixing}},

author={Aamo, Ole M. and Fossen, Thor I.},

journal={Modeling, Identification and Control},

volume={23},

number={4},

pages={275--298},

year={2002},

doi={10.4173/mic.2002.4.3},

publisher={Norwegian Society of Automatic Control}

};