In recent years, overspray fogging has become a powerful means for power augmentation of industrial gas turbines. Despite the positive thermodynamic effect on the cycle, droplets entering the compressor increase the risk of water droplet erosion and deposition of water on the blades leading to an increase of required torque and profile loss. Due to this, detailed information about the structure and the amount of water on the surface is key for compressor performance. Experiments were conducted with a droplet laden flow in a transonic compressor cascade focusing on the film formed by the deposited water. Two approaches were taken. In the first approach, the film thickness on the blade was directly measured using white light interferometry. Due to significant distortion of the flow caused by the measurement system, a transfer of the measured film thickness to the undisturbed case is not possible. Therefore, a film model is adapted to describe the film flow in terms of height averaged film parameters. In the second approach, experiments were conducted in an undisturbed cascade setup and the water film pattern was measured using a nonintrusive quantitative image processing tool. Utilizing the measured flow pattern in combination with findings from the literature, the rivulet flow structure is resolved. From continuity of the water flow, a film thickness is derived showing good agreement with the previously calculated results. Using both approaches, a three-dimensional (3D) reconstruction of the water film pattern is created giving first experimental results of the film forming on stationary compressor blades under overspray fogging conditions.

References

References
1.
Krzikalla
,
N.
,
Achner
,
S.
, and
Brühl
,
S.
,
2013
, “
Possible Solutions for Compensation of Fluctuating Energy Supply by Renewable Energies
,”
Study Commissioned by German Federal Organization for Renewable Energies
, Ponte Press, Bochum, Germany, pp.
16.1
16.13
(in German).
2.
Bhargava
,
R.
, and
Meher-Homji
,
C. B.
,
2005
, “
Parametric Analysis of Existing Gas Turbines With Inlet Evaporative and Overspray Fogging
,”
ASME J. Eng. Gas Turbines Power
,
127
(
1
), pp.
145
158
.
3.
Chaker
,
M.
,
Meher-Homji
,
C. B.
, and
Mee
,
T.
,
2002
, “
Inlet Fogging of Gas Turbine Engines—Part B: Fog Droplet Sizing Analysis, Nozzle Types, Measurement and Testing
,”
ASME
Paper No. GT2002-30563.
4.
Roumeliotis
,
I.
, and
Mathioudakis
,
K.
,
2007
, “
Water Injection Effects on Compressor Stage Operation
,”
ASME J. Eng. Gas Turbines Power
,
129
(
3
), pp.
778
784
.
5.
Ober
,
B.
, and
Joos
,
F.
,
2013
, “
Experimental Investigation on Aerodynamic Behavior of a Compressor Cascade in Droplet Laden Flow
,”
ASME
Paper No. GT2013-94731.
6.
Gyarmathy
,
G.
,
1962
, “
Grundlagen Einer Theorie Der Nassdampfturbine
,” Ph.D. thesis, ETH Zürich, Zürich, Switzerland.
7.
Hammitt
,
F. G.
,
Krzeczkowski
,
S.
, and
Krzyżanowski
,
J.
,
1981
, “
Liquid Film and Droplet Stability Consideration as Applied to Wet Steam Flow
,”
Forsch. Ingenieurwes.
,
47
(
1
), pp.
1
14
.
8.
Simon
,
A.
,
Marcelet
,
M.
,
Hérard
,
J.
,
Dorey
,
J.-M.
, and
Lance
,
M.
,
2016
, “
A Model for Liquid Film in Steam Turbines
,”
ASME
Paper No. GT2016-56148.
9.
Williams
,
J.
, and
Young
,
J. B.
,
2007
, “
Movement of Deposites Water on Turbomachinery Rotor Blade Surfaces
,”
ASME J. Eng. Gas Turbines Power
,
129
(2), pp.
394
403
.
10.
Gomaa
,
H.
,
2014
, “
Modeling of Liquid Dynamics in Spray Laden Compressor Flows
,” Ph.D. thesis, University of Stuttgart, Stuttgart, Germany.
11.
Shah
,
A. D.
,
Patnoe
,
M. W.
, and
Berg
,
E. L.
,
1998
, “
Droplet Size Distribution and Ice Shapes
,”
AIAA
Paper No. 1998-487.
12.
Rothmayer
,
A. P.
,
2003
, “
Scaling Laws for Water and Ice Layers on Airfoils
,”
AIAA
Paper No. 2003-1217.
13.
Tsao
,
J.-C.
,
Kregger
,
R. E.
, and
Feo
,
A.
,
2009
, “
Evaluation of the Water Film Weber Number in Glaze Icing Scaling
,”
AIAA
Paper No. 2009-4129.
14.
Langmuir
,
I.
, and
Blodgett
,
K.
,
1946
, “
A Mathematical Investigation of Water Droplet Trajectories
,” Army Air Forces Headquarters, Air Technical Service Command, San Antonio, TX, Report No.
5418
.https://catalog.hathitrust.org/Record/101738423
15.
Samenfink
,
W.
,
Elsäßer
,
A.
,
Dullenkopf
,
K.
, and
Wittig
,
S.
,
1999
, “
Droplet Interaction With Shear-Driven Liquid Films: Analysis of Deposition and Secondary Droplet Characteristics
,”
Int. J. Heat Fluid Flow
,
20
(
5
), pp.
462
469
.
16.
Mundo
,
C.
,
Sommerfeld
,
M.
, and
Tropea
,
C.
,
1998
, “
On the Modeling of Liquid Sprays Impinging on Surfaces
,”
Atomization Sprays
,
8
(
6
), pp.
625
652
.
17.
Al-Khalil
,
K. M.
,
Keith
,
T. G.
, and
De Witt
,
K. J.
,
1990
, “
Development of an Anti-Icing Runback Model
,”
AIAA
Paper No. 90-0759.
18.
Neupert
,
N.
,
Gomaa
,
H.
,
Joos
,
F.
, and
Weigand
,
B.
,
2017
, “
Investigation and Modeling of Two Phase Flow Through a Compressor Stage: Analysis of Film Breakup
,”
Eur. J. Mech.-B/Fluids
,
61
(
2
), pp.
279
288
.
19.
Zhang
,
K.
,
2015
, “
An Experimental Study of Wind-Driven Surface Water Transport Process Pertinent to Aircraft Icing
,” Ph.D. thesis, Iowa State University, Ames, Iowa.
20.
Itoh
,
M.
, and
Matsuno
,
S.
,
2014
, “
Scale Effect on Liquid Film Formation in a Prefilming Type Air-Blast Atomizer
,”
26th Annual Conference on Liquid Atomization and Spray Systems
, Bremen, Germany, Sept. 8–10.
21.
Ober
,
B.
,
2013
, “
Experimental Investigation on the Aerodynamic Performance of a Compressor Cascade in Droplet Laden Flow
,” Ph.D. thesis, Helmut-Schmidt University, Hamburg, Germany.
22.
Precitec Optronik
,
2015
, “
White Light Sensors
,” Precitec Optronik GmbH, Neu-Isenburg, Germany, accessed Nov. 14, 2016, http://www.precitec.de/uploads/tx_edxproductmanager/PO_overview_sensors_EN_47.pdf
23.
Neupert
,
N.
,
Harbeck
,
J. C.
, and
Joos
,
F.
,
2017
, “
Investigation on the Effect of Surface Wettability on a Two-Phase Flow in a Compressor Cascade
,”
ASME
Paper No. GT2017-64155.
24.
Neupert
,
N.
, and
Joos
,
F.
,
2015
, “
Investigation on Water Film Induced Profile Losses in a Compressor Cascade
,”
ASME
Paper No. GT2015-42153.
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