Active Control and Drag Optimization for Flow Past a Circular Cylinder

He, Jiwen; Glowinski, Roland; Metcalfe, Ralph W.; Nordlander, A.; Périaux, Jacques

doi:10.1006/jcph.2000.6556

Cited by 189 publications

(155 citation statements)

References 34 publications

(38 reference statements)

Supporting

Mentioning

131

Contrasting

Unclassified

Order By: Relevance

“…Recently, due to the maturity of control theory, optimization methods and computational fluid dynamics, optimal and suboptimal approaches attracted increased attention in flow control setting [35][36][37]. For example, in [38][39][40] the optimal control theory was used with the twodimensional Navier-Stokes equations as the state equation to control by rotary oscillation the unsteady wake of the cylinder (see table 1 for the characteristics of these approaches). An attractive element of the optimal control approach is that the control design is explicitly based on the cost functional.…”

Section: A Generic Configuration Of Separated Flows: the Cylinder Wakmentioning

confidence: 99%

Optimal control of the cylinder wake in the laminar regime by trust-region methods and POD reduced-order models

Bergmann

Cordier

2008

Journal of Computational Physics

174

152

View full text Add to dashboard Cite

In this paper, optimal control theory is used to minimize the total mean drag for a circular cylinder wake flow in the laminar regime (Re = 200). The control parameters are the amplitude and the frequency of the time-harmonic cylinder rotation. In order to reduce the size of the discretized optimality system, a Proper Orthogonal Decomposition (POD) Reduced-Order Model (ROM) is derived to be used as state equation. We then propose to employ the Trust-Region Proper Orthogonal Decomposition (TRPOD) approach, originally introduced by Fahl (2000), to update the reduced-order models during the optimization process. A lot of computational work is saved because the optimization process is now based only on low-fidelity models. A particular care was taken to derive a POD ROM for the pressure and velocity fields with an appropriate balance between model accuracy and robustness. The key enablers are the extension of the POD basis functions to the pressure data, the use of calibration methods for the POD ROM and the addition in the POD expansion of several non-equilibrium modes to describe various operating conditions. When the TRPOD algorithm is applied to the wake flow configuration, this approach converges to the minimum predicted by an open-loop control approach and leads to a relative mean drag reduction of 30% at reduced cost.

show abstract

Section: A Generic Configuration Of Separated Flows: the Cylinder Wakmentioning

confidence: 99%

Optimal control of the cylinder wake in the laminar regime by trust-region methods and POD reduced-order models

Bergmann

Cordier

2008

Journal of Computational Physics

174

152

View full text Add to dashboard Cite

show abstract

“…More sophisticated storage management techniques, which will be considered in the future, are discussed in References [1,7,41].…”

Section: Optimization Algorithmmentioning

confidence: 99%

“…The papers [1][2][3][4][5][6][7][8][9][10][11] present a sample of recent activities in the former category and References [12][13][14][15][16][17] illustrate activities in the latter category. To the authors' knowledge, the present paper documents the ÿrst approach to the optimal boundary control of unsteady compressible viscous ows.…”

Section: Introductionmentioning

confidence: 99%

“…These choices are motivated by the existing work on control of incompressible Navier-Stokes equations. In References [1,7,11] the control is only time dependent and in Reference [10] the control varies in time and only over a small portion of the boundary, i.e. it is essentially dependent only one time.…”

Section: Introductionmentioning

confidence: 99%

“…it is essentially dependent only one time. Therefore, in References [1,7,10,11] the regularization term for the control involves only t f t0 c |g| 2 + |g t | 2 . In the papers [2,3,11] the control varies over a large portion of the boundary and in time, but the regularization terms used are essentially denote the primitive ow variables, where (t; x) is the density; v i (t; x) denotes the velocity in the x i -direction, i = 1; 2; v = (v 1 ; v 2 ) T ; and T (t; x) denotes the temperature.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Optimal control of unsteady compressible viscous flows

Collis

Ghayour

Heinkenschloss

et al. 2002

Numerical Methods in Fluids

View full text Add to dashboard Cite

SUMMARYThe control of complex, unsteady ows is a pacing technology for advances in uid mechanics. Recently, optimal control theory has become popular as a means of predicting best case controls that can guide the design of practical ow control systems. However, most of the prior work in this area has focused on incompressible ow which precludes many of the important physical ow phenomena that must be controlled in practice including the coupling of uid dynamics, acoustics, and heat transfer. This paper presents the formulation and numerical solution of a class of optimal boundary control problems governed by the unsteady two-dimensional compressible Navier-Stokes equations. Fundamental issues including the choice of the control space and the associated regularization term in the objective function, as well as issues in the gradient computation via the adjoint equation method are discussed. Numerical results are presented for a model problem consisting of two counter-rotating viscous vortices above an inÿnite wall which, due to the self-induced velocity ÿeld, propagate downward and interact with the wall. The wall boundary control is the temporal and spatial distribution of wall-normal velocity. Optimal controls for objective functions that target kinetic energy, heat transfer, and wall shear stress are presented along with the in uence of control regularization for each case.

show abstract

Programmable Aerodynamic Drag on Active Dimpled Cylinders

2019

View full text Add to dashboard Cite

This study demonstrates that the aerodynamic drag profile of a patterned deformable cylinder at high Reynolds numbers can be programmed, on demand, by modifying its topography through pneumatic actuation. The samples used in the experiments comprise a rigid tube containing a hexagonal array of holes, over which an elastomeric cylindrical membrane is stretched. Decreasing the internal pressure of the structure causes an inward deflection of the outer membrane over the holes, thereby producing a regular pattern of dimples. The depth of these dimples can be controlled by tuning the pressure differential. The relationship between the mechanical deformation of the membrane and the pneumatic loading is characterized using a combination of finite element simulations and precision mechanical experiments.Wind tunnel experiments are performed to study how both the depth and the diameter of the dimples dictate the aerodynamic performance of the samples in the critical Reynolds number regime. Finally, the tunable nature of the specimens is exploited to automatically control the dependence of the drag coefficient on the Reynolds number, toward targeting predefined drag profiles.

show abstract

Active Control and Drag Optimization for Flow Past a Circular Cylinder

Cited by 189 publications

References 34 publications

Optimal control of the cylinder wake in the laminar regime by trust-region methods and POD reduced-order models

Optimal control of the cylinder wake in the laminar regime by trust-region methods and POD reduced-order models

Optimal control of unsteady compressible viscous flows

Programmable Aerodynamic Drag on Active Dimpled Cylinders

Contact Info

Product

Resources

About