The precessing vortex core (PVC) represents a helical-shaped coherent flow structure typically occurring in both reacting and nonreacting swirling flows. Until now, the fundamental impact of the PVC on flame dynamics, thermoacoustic instabilities, and pollutant emissions is still unclear. In order to identify and investigate these mechanisms, the PVC needs to be controlled effectively with a feedback control system. A previous study successfully applied feedback control in a generic swirling jet setup. The next step is to transfer this approach into a swirl-stabilized combustor, which poses big challenges on the actuator and sensor design and placement. In this paper, different actuator designs are investigated with the goal of controlling the PVC dynamics. The actuation strategy aims to force the flow near the origin of the instability—the so-called wavemaker. To monitor the PVC dynamics, arrays of pressure sensors are flush-mounted at the combustor inlet and the combustion chamber walls. The best sensor placement is evaluated with respect to the prediction of the PVC dynamics. Particle image velocimetry (PIV) is used to evaluate the passive impact of the actuator shape on the mean flow field. The performance of each actuator design is evaluated from lock-in experiments showing excellent control authority for two out of seven actuators. All measurements are conducted at isothermal conditions in a prototype of a swirl-stabilized combustor.

References

References
1.
Syred
,
N.
,
2006
, “
A Review of Oscillation Mechanisms and the Role of the Precessing Vortex Core (PVC) in Swirl Combustion Systems
,”
Prog. Energy Combust. Sci.
,
32
(
2
), pp.
93
161
.
2.
Petz
,
C.
,
Hege
,
H.-C.
,
Oberleithner
,
K.
,
Sieber
,
M.
,
Nayeri
,
C. N.
,
Paschereit
,
C. O.
,
Wygnanski
,
I.
, and
Noack
,
B. R.
,
2011
, “
Global Modes in a Swirling Jet Undergoing Vortex Breakdown
,”
Phys. Fluids
,
23
(
9
), p.
091102
.
3.
Gallaire
,
F.
,
Ruith
,
M.
,
Meiburg
,
E.
,
Chomaz
,
J.-M.
, and
Huerre
,
P.
,
2006
, “
Spiral Vortex Breakdown as a Global Mode
,”
J. Fluid Mech.
,
549
, pp.
71
80
.
4.
Oberleithner
,
K.
,
Sieber
,
M.
,
Nayeri
,
C. N.
,
Paschereit
,
C. O.
,
Petz
,
C.
,
Hege
,
H.-C.
,
Noack
,
B. R.
, and
Wygnanski
,
I.
,
2011
, “
Three-Dimensional Coherent Structures in a Swirling Jet Undergoing Vortex Breakdown: Stability Analysis and Empirical Mode Construction
,”
J. Fluid Mech.
,
679
, pp.
383
414
.
5.
Qadri
,
U. A.
,
Mistry
,
D.
, and
Juniper
,
M. P.
,
2013
, “
Structural Sensitivity of Spiral Vortex Breakdown
,”
J. Fluid Mech.
,
720
, pp.
558
581
.
6.
Tammisola
,
O.
, and
Juniper
,
M.
,
2016
, “
Coherent Structures in a Swirl Injector at Re = 4800 by Nonlinear Simulations and Linear Global Modes
,”
J. Fluid Mech.
,
792
, pp.
620
657
.
7.
Rukes
,
L.
,
Paschereit
,
C. O.
, and
Oberleithner
,
K.
,
2016
, “
An Assessment of Turbulence Models for Linear Hydrodynamic Stability Analysis of Strongly Swirling Jets
,”
Eur. J. Mech.: B
,
59
, pp.
205
218
.
8.
Oberleithner
,
K.
,
Stöhr
,
M.
,
Im
,
S. H.
,
Arndt
,
C. M.
, and
Steinberg
,
A. M.
,
2015
, “
Formation and Flame-Induced Suppression of the Precessing Vortex Core in a Swirl Combustor: Experiments and Linear Stability Analysis
,”
Combust. Flame
,
162
(
8
), pp.
3100
3114
.
9.
Moeck
,
J. P.
,
Bourgouin
,
J.-F.
,
Durox
,
D.
,
Schuller
,
T.
, and
Candel
,
S.
,
2012
, “
Nonlinear Interaction Between a Precessing Vortex Core and Acoustic Oscillations in a Turbulent Swirling Flame
,”
Combust. Flame
,
159
(
8
), pp.
2650
2668
.
10.
Terhaar
,
S.
,
Ćosić
,
B.
,
Paschereit
,
C.
, and
Oberleithner
,
K.
,
2016
, “
Suppression and Excitation of the Precessing Vortex Core by Acoustic Velocity Fluctuations: An Experimental and Analytical Study
,”
Combust. Flame
,
172
, pp.
234
251
.
11.
Ghani
,
A.
,
Poinsot
,
T.
,
Gicquel
,
L.
, and
Müller
,
J.-D.
,
2016
, “
LES Study of Transverse Acoustic Instabilities in a Swirled Kerosene/Air Combustion Chamber
,”
Flow, Turbul. Combust.
,
96
(
1
), pp.
207
226
.
12.
Stöhr
,
M.
,
Arndt
,
C.
, and
Meier
,
W.
,
2015
, “
Transient Effects of Fuel–Air Mixing in a Partially-Premixed Turbulent Swirl Flame
,”
Proc. Combust. Inst.
,
35
(
3
), pp.
3327
3335
.
13.
Terhaar
,
S.
,
Krüger
,
O.
, and
Paschereit
,
C. O.
,
2015
, “
Flow Field and Flame Dynamics of Swirling Methane and Hydrogen Flames at Dry and Steam-Diluted Conditions
,”
ASME J. Eng. Gas Turbines Power
,
137
(
4
), p.
041503
.
14.
Kuhn
,
P.
,
Moeck
,
J. P.
,
Paschereit
,
C. O.
, and
Oberleithner
,
K.
,
2016
, “
Control of the Precessing Vortex Core by Open and Closed-Loop Forcing in the Jet Core
,”
ASME
Paper No. GT2016-57686.
15.
Terhaar
,
S.
,
Oberleithner
,
K.
, and
Paschereit
,
C.
,
2015
, “
Key Parameters Governing the Precessing Vortex Core in Reacting Flows: An Experimental and Analytical Study
,”
Proc. Combust. Inst.
,
35
(
3
), pp.
3347
3354
.
16.
Oberleithner
,
K.
,
Terhaar
,
S.
,
Rukes
,
L.
, and
Paschereit
,
C. O.
,
2013
, “
Why Nonuniform Density Suppresses the Precessing Vortex Core
,”
ASME J. Eng. Gas Turbines Power
,
135
(
12
), p.
121506
.
17.
Li
,
L. K. B.
, and
Juniper
,
M. P.
,
2013
, “
Lock-In and Quasiperiodicity in a Forced Hydrodynamically Self-Excited Jet
,”
J. Fluid Mech.
,
726
, pp.
624
655
.
18.
Sieber
,
M.
,
Paschereit
,
C. O.
, and
Oberleithner
,
K.
,
2016
, “
Spectral Proper Orthogonal Decomposition
,”
J. Fluid Mech.
,
792
, pp.
798
828
.
19.
Sieber
,
M.
,
Paschereit
,
C. O.
, and
Oberleithner
,
K.
,
2016
, “
Advanced Identification of Coherent Structures in Swirl-Stabilized Combustors
,”
ASME J. Eng. Gas Turbines Power
,
139
(
2
), p.
021503
.
20.
Akilli
,
H.
,
Sahin
,
B.
, and
Rockwell
,
D.
,
2003
, “
Control of Vortex Breakdown by a Coaxial Wire
,”
Phys. Fluids
,
15
(
1
), pp.
123
133
.
21.
Leuckel
,
W.
,
1967
, “
Swirl Intensities, Swirl Types and Energy Losses of Different Swirl Generating Devices
,”
International Flame Research Foundation
, Ijmuiden, The Netherlands, Technical Report No.
G02/a/16
.http://copac.jisc.ac.uk/id/27957912?style=html&title=Swirl%20intensities%2C%20swirl%20types%20and%20energy%20losses%20of
22.
Soria
,
J.
,
1996
, “
An Investigation of the Near Wake of a Circular Cylinder Using a Video-Based Digital Cross-Correlation Particle Image Velocimetry Technique
,”
Exp. Therm. Fluid Sci.
,
12
(
2
), pp.
221
233
.
23.
Huang
,
H. T.
,
Fiedler
,
H. E.
, and
Wang
,
J. J.
,
1993
, “
Limitation and Improvement of PIV
,”
Exp. Fluids
,
15
(
4–5
), pp.
263
273
.
24.
Holmes
,
P.
,
Lumley
,
J. L.
, and
Berkooz
,
G.
,
1998
,
Turbulence, Coherent Structures, Dynamical Systems and Symmetry
(Cambridge Monographs on Mechanics),
Cambridge University Press
, Cambridge, UK.
25.
Terhaar
,
S.
,
Reichel
,
T. G.
,
Schrödinger
,
C.
,
Rukes
,
L.
,
Paschereit, C. O.
, and
Oberleithner, K.
,
2015
, “
Vortex Breakdown Types and Global Modes in Swirling Combustor Flows With Axial Injection
,”
J. Propul. Power
,
31
(1), pp. 219–229.
26.
Greenblatt
,
D.
, and
Wygnanski
,
I. J.
,
2000
, “
The Control of Flow Separation by Periodic Excitation
,”
Prog. Aerosp. Sci.
,
36
(
7
), pp.
487
545
.
27.
Li
,
L. K.
, and
Juniper
,
M.
,
2013
, “
Phase Trapping and Slipping in a Forced Hydrodynamically Self-Excited Jet
,”
J. Fluid Mech.
,
735
, p. R5.
You do not currently have access to this content.