Abstract

As a consequence of constant volume combustion in gas turbines, pressure waves propagating upstream the main flow into the compressor system are generated leading to incidence variations. Numerical and experimental investigations of stator vanes have shown that active flow control (AFC) by means of adaptive blade geometries is beneficial when such periodic incidence variations occur. A significant risk reduction in a compressor facing disturbances can thereby be achieved concerning stall or choke. Experimental investigations on such an AFC method with simultaneous application of a closed-loop control are missing in order to demonstrate its potential. This work investigates a linear compressor cascade that is equipped with a 3D-manufactured piezo-adaptive blade structure. The utilized actuators are piezoelectric macro-fiber-composites. A throttling device is positioned downstream the trailing edge plane to emulate an unsteady combustion process. Periodic transient throttling events with a frequency of up to 20 Hz cause incidence changes to the blade’s leading edge. Consequently, pressure fluctuations on the blade’s surface occur, having a significant impact on the pressure recovery downstream of the stator cascade. Experimental results of harmonically actuating the piezo-adaptive blade with the corresponding disturbance frequency show that the impact of disturbances can be reduced to approximately 50%. However, this is only effective if the phase shift of the harmonic actuation is adjusted correctly. Using an inadequate phase shift reverses the positive effects, causing the aforementioned stall, choke, or significant losses. In order to find the optimum phase shift, even under varying, possibly unpredictable operating conditions, an extremum seeking controller is presented. This gradient-based approach is minimizing the pressure variance over time by carefully adjusting the phase shift of the harmonic actuation of the AFC system.

References

References
1.
Staats
,
M.
, and
Nitsche
,
W.
,
2015
, “
Active Control of the Corner Separation on a Highly Loaded Compressor Cascade With Periodic Nonsteady Boundary Conditions by Means of Fluidic Actuators
,”
ASME J. Turbomach.
,
138
(
3
), p.
031004
. 10.1115/1.4031934
2.
Steinberg
,
S.
,
King
,
R.
,
Staats
,
M.
, and
Nitsche
,
W.
,
2015
, “
Iterative Learning Active Flow Control Applied to a Compressor Stator Cascade With Periodic Disturbances
,”
ASME J. Turbomach.
,
137
(
11
), p.
111003
. 10.1115/1.4031251
3.
Hammer
,
S.
,
Phan
,
D. T.
,
Peter
,
J.
,
Werder
,
T.
,
Meyer
,
R.
,
Liebich
,
R.
, and
Thamsen
,
P. U.
,
2014
, “
Active Flow Control by Adaptive Blade Systems in Periodic Unsteady Flow Conditions
,”
Active Flow and Combustion Control 2014
,
Berlin, Germany
,
Sept. 10–12
.
4.
Phan
,
T. D.
,
Springer
,
P.
, and
Liebich
,
R.
,
2017
, “
Numerical Investigation of an Elastomer-Piezo-Adaptive Blade for Active Flow Control of a Nonsteady Flow Field Using Fluid–Structure Interaction Simulations
,”
ASME J. Turbomach.
,
139
(
9
), p.
091004
. 10.1115/1.4036107
5.
Phan
,
T. D.
,
2019
, “
Experimentelle und numerische Untersuchung des strukturdynamischen und strömungsmechanischen Verhaltens einer piezoadaptiven Verdichterschaufel zur Strömungsbeeinflussung
”, http://dx.doi.org/10.14279/depositonce-40.
6.
Draper
,
C. S.
, and
Li
,
Y. T.
,
1951
,
Principles of Optimalizing Control Systems and an Application to the Internal Combustion Engine
,
American Society of Mechanical Engineers
,
New York
.
7.
Krstic
,
M.
, and
Wang
,
H.-H.
,
2000
, “
Stability of Extremum Seeking Feedback for General Nonlinear Dynamic Systems
,”
Automatica
,
36
(
4
), pp.
595
601
. 10.1016/S0005-1098(99)00183-1
8.
Aarsnes
,
U. J.
,
Aamo
,
O.
, and
Krstic
,
M.
,
2019
, “
Extremum Seeking for Real-Time Optimal Drilling Control
,”
2019 American Control Conference (ACC)
,
Philadelphia, PA
,
July 10–12
.
9.
Mustafa
,
A.
, and
Morita
,
T.
,
2019
, “
Efficiency Optimization of Rotary Ultrasonic Motors Using Extremum Seeking Control With Current Feedback
,”
Sens. Actuators A
,
289
, pp.
26
33
. 10.1016/j.sna.2019.02.022
10.
Fietzke
,
B.
,
Kiesner
,
M.
,
Berthold
,
A.
,
Haucke
,
F.
, and
King
,
R.
,
2019
,
Map Estimation for Impingement Cooling With a Fast Extremum Seeking Algorithm
,
Springer
,
Berlin
, pp.
367
378
.
11.
Topalovic
,
Daniel
,
Wolff
,
Sasha
,
Heinrich
,
Alexander
,
Peitsch
,
Dieter
, and
King
,
Rudibert
,
2019
, “
Minimization of Pressure Fluctuations in an Axial Turbine Stage Under Periodic Inflow Conditions
,”
AIAA Propulsion and Energy 2019 Forum
,
Indianapolis, IN
, p.
4213
.
12.
Tan
,
Y.
,
Moase
,
W. H.
,
Manzie
,
C.
,
Nešić
,
D.
, and
Mareels
,
I.
,
2010
, “
Extremum Seeking From 1922 to 2010
,”
Proceedings of the 29th Chinese Control Conference
,
Beijing, China
,
IEEE
, pp.
14
26
.
13.
Steinert
,
W.
, and
Starken
,
H.
,
1996
, “
Off-Design Transition and Separation Behavior of a CDA Cascade
,”
ASME J. Turbomach.
,
118
(
2
), pp.
204
210
. 10.1115/1.2836627
You do not currently have access to this content.