Research Papers: Gas Turbines: Turbomachinery

An Experimentally Derived Model to Predict the Water Film in a Compressor Cascade With Droplet Laden Flow

[+] Author and Article Information
Niklas Neupert

Laboratory for Tubomachinery,
Department of Power Engineering,
Helmut Schmidt University,
Hamburg D-22043, Germany
e-mail: Niklas.Neupert@gmx.de

Janneck Christoph Harbeck

Laboratory for Turbomachinery,
Department of Power Engineering,
Helmut Schmidt University,
Hamburg D-22043, Germany
e-mail: Harbeck@hsu-hh.de

Franz Joos

Laboratory for Tubomachinery,
Department of Power Engineering,
Helmut Schmidt University,
Hamburg D-22043, Germany
e-mail: Joos@hsu-hh.de

Contributed by the Turbomachinery Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received September 14, 2017; final manuscript received October 9, 2017; published online June 5, 2019. Assoc. Editor: David Wisler.

J. Eng. Gas Turbines Power 141(9), 092601 (Jun 05, 2019) (10 pages) Paper No: GTP-17-1512; doi: 10.1115/1.4043690 History: Received September 14, 2017; Revised October 09, 2017

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.

Copyright © 2019 by ASME
Your Session has timed out. Please sign back in to continue.


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).
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. [CrossRef]
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.
Roumeliotis, I. , and Mathioudakis, K. , 2007, “ Water Injection Effects on Compressor Stage Operation,” ASME J. Eng. Gas Turbines Power, 129(3), pp. 778–784. [CrossRef]
Ober, B. , and Joos, F. , 2013, “ Experimental Investigation on Aerodynamic Behavior of a Compressor Cascade in Droplet Laden Flow,” ASME Paper No. GT2013-94731.
Gyarmathy, G. , 1962, “ Grundlagen Einer Theorie Der Nassdampfturbine,” Ph.D. thesis, ETH Zürich, Zürich, Switzerland.
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. [CrossRef]
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.
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. [CrossRef]
Gomaa, H. , 2014, “ Modeling of Liquid Dynamics in Spray Laden Compressor Flows,” Ph.D. thesis, University of Stuttgart, Stuttgart, Germany.
Shah, A. D. , Patnoe, M. W. , and Berg, E. L. , 1998, “ Droplet Size Distribution and Ice Shapes,” AIAA Paper No. 1998-487.
Rothmayer, A. P. , 2003, “ Scaling Laws for Water and Ice Layers on Airfoils,” AIAA Paper No. 2003-1217.
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.
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.
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. [CrossRef]
Mundo, C. , Sommerfeld, M. , and Tropea, C. , 1998, “ On the Modeling of Liquid Sprays Impinging on Surfaces,” Atomization Sprays, 8(6), pp. 625–652. [CrossRef]
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.
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. [CrossRef]
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.
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.
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.
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
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.
Neupert, N. , and Joos, F. , 2015, “ Investigation on Water Film Induced Profile Losses in a Compressor Cascade,” ASME Paper No. GT2015-42153.


Grahic Jump Location
Fig. 1

OCS profile under droplet laden flow at design inflow Mach number and incidence angle α = 4 deg

Grahic Jump Location
Fig. 2

Definition of the impact region

Grahic Jump Location
Fig. 3

Forces acting on a shear driven rivulet [17]

Grahic Jump Location
Fig. 4

Assumed shape of rivulets for different rivulet widths

Grahic Jump Location
Fig. 5

Velocity profiles for varying θ: linear velocity profile (dotted), analytical velocity profile (dashed), and numerically calculated velocity profile (solid)

Grahic Jump Location
Fig. 6

Sketch of the test rig

Grahic Jump Location
Fig. 7

Film thickness measurement setup

Grahic Jump Location
Fig. 8

Local film thickness at α = −3 deg (OCS, circle) and α = −4 deg (MCS, triangle) at v1 = 80–160 m/s and spray A

Grahic Jump Location
Fig. 9

Influences on the film movement on the suction side in measurement setup (gray) and in clean condition (black). For the measurement setup, the boundary conditions were set to the maximum possible inlet velocity v1 = 160 m/s and α = 0 deg, and for the clean condition, the design case of the cascade v1 = 290 m/s and α = 0 deg.

Grahic Jump Location
Fig. 10

Nondimensionalized film height H+ for v1 = 80–160 m/s, α = −4 deg (MCS, triangle) and α = −3 deg (OCS, circles) on the suction side for spray A (open symbols) and spray B (filled symbols). The lines represent the calculated results for ηcoll = 1.

Grahic Jump Location
Fig. 11

Comparison of different functions for ηimp for the OCS profile at v1 = 100 m/s, spray A and α = −3 deg

Grahic Jump Location
Fig. 12

Comparison of different functions for ηdep for the OCS profile at v1 = 100 m/s, spray A and α = −3 deg

Grahic Jump Location
Fig. 13

Calculated film thickness for the clean cascade flow for the OCS (black) and MCS (gray) profile at design Mach number, spray A and α = 0 deg (solid) and α = 4 deg (dashed)

Grahic Jump Location
Fig. 14

Detached flow on suction side of MCS under design Mach number, spray A and α = 4 deg

Grahic Jump Location
Fig. 15

Processed images for α = −4 deg, 0 deg, and 4 deg (upper left), the histogram curves for the relative film breakup position x/c (upper right), the rivulet width b (lower left), and the fraction of wetted surface in the rivulet region F (lower right)

Grahic Jump Location
Fig. 16

Results of the nondimensionalized film thickness at film breakup for the MCS (gray) and OCS (black) profile

Grahic Jump Location
Fig. 17

Derived 3D wall film pattern for MCS at design Mach number with spray A and α = 4 deg



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In