×

zbMATH — the first resource for mathematics

Feedback control for form-drag reduction on a bluff body with a blunt trailing edge. (English) Zbl 1246.76023
Summary: The objective of this numerical study is to increase the base pressure on a backward-facing step via linear feedback control, to be ultimately translated to a drag reduction on a blunt-based bluff body. Two backward-facing step cases are simulated: a laminar two-dimensional (2D) flow at a Reynolds number of \(Re_\theta=280\), and a turbulent three-dimensional (3D) flow \(Re_\theta=1500\) at using large-eddy simulation. The control is effected by a full-span slot jet with zero-net-mass-flux, and two jet locations are examined. Linear system identification is performed to characterize the flow response to actuation, used to synthesize a control law. The control strategy is based on the premise that an attenuation of the instantaneous pressure fluctuations on the base of the step should lead to an increase in the time-averaged base pressure. Open-loop harmonic forcing is examined within a broad frequency range for both the 2D and 3D flows, which are found to respond differently to actuation. The controllers based on disturbance attenuation lead to sensible increases in base pressure (up to 70 % in 2D and 20 % in 3D) with higher efficiency than the best results achieved in open-loop. The results support the conjecture about the link between the base pressure fluctuations and mean, although it is shown that such a black-box model approach is not suitable for optimization without further physical insight.

MSC:
76D55 Flow control and optimization for incompressible viscous fluids
76M12 Finite volume methods applied to problems in fluid mechanics
PDF BibTeX XML Cite
Full Text: DOI
References:
[1] DOI: 10.1016/0142-727X(92)90035-8
[2] DOI: 10.1017/S002211207200299X
[3] DOI: 10.1017/S0022112092001642
[4] DOI: 10.1016/j.ijheatfluidflow.2007.04.002
[5] DOI: 10.1016/j.paerosci.2008.07.002
[6] Gelb, Multiple-Input Describing Functions and Nonlinear System Design (1968) · Zbl 0177.12602
[7] DOI: 10.1017/S0022112084001415
[8] DOI: 10.1146/annurev-fluid-122109-160634 · Zbl 1299.76108
[9] Gad-el Hak, Flow Control, Fundamentals and Practices (1998) · Zbl 0896.76001
[10] DOI: 10.1016/j.compfluid.2008.12.003 · Zbl 1242.76202
[11] Tanner, Aeronaut. Q. 23 pp 15– (1972)
[12] DOI: 10.1017/S0022112006003995 · Zbl 1133.76324
[13] DOI: 10.1016/j.compfluid.2004.11.002 · Zbl 1134.76335
[14] DOI: 10.1007/s00162-010-0197-3 · Zbl 1272.76014
[15] DOI: 10.2514/3.9317
[16] DOI: 10.2514/3.60048
[17] DOI: 10.1007/s003480000234
[18] DOI: 10.1260/1756-8250.2.2.109
[19] DOI: 10.2514/3.8890
[20] DOI: 10.1146/annurev.fl.21.010189.001225
[21] DOI: 10.1146/annurev.fluid.36.050802.122038 · Zbl 1117.76072
[22] DOI: 10.2514/1.4443
[23] DOI: 10.1016/j.ijheatfluidflow.2004.03.004
[24] DOI: 10.1007/978-3-540-85070-0_10
[25] DOI: 10.1017/S0022112008002073 · Zbl 1145.76306
[26] DOI: 10.1017/S0022112006001364 · Zbl 1178.76042
[27] DOI: 10.1023/A:1009995426001 · Zbl 0980.76036
[28] DOI: 10.1016/0167-6105(94)00074-N
[29] McFarlane, Robust Controller Design Using Normalized Coprime Factor Plant Descriptions (1989) · Zbl 0688.93044
[30] DOI: 10.1007/s00162-010-0184-8 · Zbl 1272.76103
[31] DOI: 10.1006/jcph.1998.5882 · Zbl 0936.76026
[32] Ljung, System Identification: Theory for the User (1999) · Zbl 0615.93004
[33] DOI: 10.1098/rsta.2010.0363
[34] DOI: 10.1017/S0022112096003941 · Zbl 0900.76367
[35] Kim, Proceedings of the 2006 American Control Conference pp 5318– (2006)
[36] DOI: 10.1088/1468-5248/5/1/019
[37] DOI: 10.2514/3.20031 · Zbl 0589.93008
[38] DOI: 10.1017/S0022112010001370 · Zbl 1197.76063
[39] DOI: 10.2514/1.22934
[40] DOI: 10.1109/CDC.2005.1582204
[41] DOI: 10.1016/S0142-727X(01)00092-3
[42] DOI: 10.2514/2.474
[43] DOI: 10.1017/S0022112067000795
[44] DOI: 10.1016/S0997-7546(00)01105-5 · Zbl 0982.76502
[45] DOI: 10.1007/s003480050217
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.