A Simulation Framework for Testing Flow Control

StrategiesMarek Gayer, Milan Milovanovic and Ole Morten Aamo

Faculty of Information Technology, Mathematics and Electrical Engineering

Department of Engineering Cybernetics

The 18th IASTED International Conference on Applied Simulation and Modelling ~ASM 2009

September 7 – 9, 2009Palma de Mallorca, Spain

http://www.itk.ntnu.no

Introduction 1/2: Flow control of vortex shedding around 2D cylinder

2ASM 2009

Introduction 2/2: Flow control with suction/blowing actuation slots

3ASM 2009

Post-processingPost-processingResultsResults

Flow control module

Flow control module

Simulation caseSimulation case

VISTA withDiffpack

VISTA withDiffpack

Navier-Stokes solver and dataNavier-Stokes solver and data

Utility libraryUtility library

GridGrid

Actuation --- Feedback

Simulation framework architecture

ASM 2009 4

Code VISTA – CFD/N-S solver

Finite element method based incompressible Navier-Stokes solver

C++, using Diffpack numerical package VISTA menu system reads parameters

from extendible input case files Additional parameters provided in files Support for computational grids, VTF

data sets, restarting simulations

5ASM 2009

Flow control modules

Realizes simulation of a flow controller Reads data for a control case Reads variables from N-S CFD code Implement a controller computation Applies computed values back to N-S Output results to files Implemented as inherited C++ classes

6ASM 2009

Utility Library

Provides general functionality for Flow Control modules

Uses VISTA and Diffpack Routines for real and complex matrix

and vector classes Reading and writing data files Uses special .m files for input/output

7ASM 2009

Simplified Ginzburg-Landau equation

for , with boundary conditions and

Stabilizing state feedback controller:

Case study: Control of vortex shedding around cylinders with G-L

8ASM 2009

)(),0( tutA

),0( dxx

0),( txA d

1 ,10

201

1( ) ( , )

1exp ( )

2

dx d dc

d d d

x

x x x xu t k ik A x t

x x x

a d dxa

Curves along which A – transversal velocities are measured

9ASM 2009

Computational grid for VISTA CFD

10ASM 2009

Stabilization of fully developed vortex shedding; Re=60 (GL Inova)

11ASM 2009

Suppression of transversal velocities

12ASM 2009

Monitoring of simulation control related parameters in MATLAB

13ASM 2009

3D plot of pressures around the cylinder boundary (±180º)

14ASM 2009

Conclusion

Simulation Framework for incompressible fluid flow control featuring:– CFD code VISTA (Navier-Stokes based)– Flow Control Module(s)– Utility Library– Input cases with grid input files

Results visualized/real time monitored in MATLAB and GL Inova

Case study removes vortex sheddding;Re=60

15ASM 2009

16ASM 2009

Possible future effort

Extend to work with the output feedback problem, for the G-L eq. in [Aamo2007]

Try for Re > 60 Develop simulation cases and modules

for 3D control of fluid flows Implement parallel processing

17ASM 2009

Thank you for your attention.

???Do you have any questions ?