Optimal Control of Unsteady Stokes Flow Around a Cylinder and the Sensor/Actuator Placement Problem

Abstract

Effective placement of sensors and actuators is of crucial importance in flow control. Instead of using combinatorial search to identify optimal locations, we pose a related problem of polynomial complexity. If one could sense everything and actuate everywhere, what should one do? Using the unsteady two dimensional Stokes flow around a cylinder as an example, we obtain the analytic solution of an optimal distributed control problem and describe its spatial structure. At low circumferential wavenumbers or close to the cylinder wall, boundary vortex generators are shown to be more effective than colocated vorticity damping. This analytic solution has also been used to test numerical methods, demonstrating the importance of using discretization which resolves all eigenfunctions of interest.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1998
Accession Number
ADA349441

Entities

People

  • Josip Lonaric

Tags

Communities of Interest

  • Energy and Power Technologies
  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Actuators
  • Bessel Functions
  • Boundary Layer
  • Cartesian Coordinates
  • Computational Fluid Dynamics
  • Computational Science
  • Differential Equations
  • Dynamics
  • Eigenvalues
  • Eigenvectors
  • Equations
  • Flow
  • Fluid Dynamics
  • Kinetic Energy
  • Navier Stokes Equations
  • Stratified Fluids
  • Two Dimensional

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Operations Research
  • Robotics and Automation.