0
Research Papers

Experimental Simulation of Contaminant Deposition on a Film-Cooled Turbine Vane Pressure Side With a Trench

[+] Author and Article Information

Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712

1Present address: GE Energy, Greenville, SC.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the Journal of Turbomachinery. Manuscript received April 28, 2012; final manuscript received September 30, 2012; published online June 26, 2013. Editor: David Wisler.

J. Turbomach 135(5), 051008 (Jun 26, 2013) (11 pages) Paper No: TURBO-12-1036; doi: 10.1115/1.4007821 History: Received April 28, 2012; Revised September 30, 2012

An important issue in the use of coal- or biomass-derived synthetic gaseous (syngas) fuels is the deposition of contaminants on film-cooled turbine surfaces, which alter cooling and aerodynamic performance and increase material degradation. The current study applied a new experimental technique that simulated the key physical aspects of contaminant deposition on a film-cooled turbine vane. The depositing contaminants were modeled in a wind tunnel facility with a spray of molten wax droplets of a size range that matched the Stokes number of the contaminant particles in engine conditions. Most experiments were performed using a vane model with a thermal conductivity selected such that the model had the same Biot number of an actual engine airfoil, resulting in a cooler surface temperature. Some experiments were performed using an approximately adiabatic model for comparison. The film cooling design consisted of three rows of showerhead cooling at the leading edge and one row of body film cooling holes on the pressure side. Two designs of pressure side body film cooling holes were considered: a standard design of straight, cylindrical holes and an advanced design of “trenched” cooling holes in which the hole exits were situated in a recessed, transverse trench. The results showed thin deposits formed in the trench, with the thickest deposits on its downstream wall between coolant jets. Adiabatic film effectiveness levels were essentially unchanged by the presence of deposits for either film configuration. Deposit formation was strongly influenced by the model surface temperature with cooler surfaces inhibiting deposition. There was evidence of a threshold surface temperature above which deposits became significantly thicker.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Wind tunnel test section schematic

Grahic Jump Location
Fig. 2

Vane model cross section schematic with hatch locations shown

Grahic Jump Location
Fig. 3

PS film row trenched cooling hole schematic

Grahic Jump Location
Fig. 4

Wax spray device (a) schematic and (b) photo in situ

Grahic Jump Location
Fig. 5

Scanning electron microscope image of wax spray sample

Grahic Jump Location
Fig. 6

Photo of deposits: nonfilm-cooled, isothermal vane (T = Tc = 305 K) (maximum tdep = 3.1 mm at location marked by a circle)

Grahic Jump Location
Fig. 7

Photo of deposits: nonfilm-cooled, internally cooled vane (T = 305 K, Tc = 220 K, DR = 1.4) (maximum tdep = 5.3 mm at location marked by a circle)

Grahic Jump Location
Fig. 8

Photo of deposits: film-cooled, matched-Bi vane with standard PS holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4)

Grahic Jump Location
Fig. 9

Photo of deposits: film-cooled, matched-Bi vane, with standard PS holes, lower blowing ratio (MPS = 1.0, M*Shd = 0.75, DR = 1.4)

Grahic Jump Location
Fig. 10

Detailed photos of deposits at showerhead for different blowing ratios (DR = 1.4)

Grahic Jump Location
Fig. 11

Photo of deposits: film-cooled, low-conductivity vane with standard PS holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4)

Grahic Jump Location
Fig. 12

Detailed photos of deposits at standard PS film holes for different model conductivities (DR = 1.4)

Grahic Jump Location
Fig. 13

Laterally averaged ϕ and η for the vane with showerhead + standard PS holes, prior to deposition (MPS = 2.0, M*Shd = 2.0, DR = 1.4) (these data correspond to the conditions used to simulate deposits shown in Figs. 8 and 11)

Grahic Jump Location
Fig. 14

Laterally averaged deposit thickness for the vane models with showerhead + standard PS holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4) (these data correspond to the deposits shown in Figs. 8 and 11)

Grahic Jump Location
Fig. 15

Photo of deposits: film-cooled, matched-Bi vane with trenched PS holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4)

Grahic Jump Location
Fig. 16

Detailed photos of deposits at standard and trenched PS film holes (DR = 1.4)

Grahic Jump Location
Fig. 17

Effect of deposits on laterally averaged η for standard and trenched PS film holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4)

Grahic Jump Location
Fig. 18

Effect of deposits on η contours for standard and trenched PS film holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4)

Tables

Errata

Discussions

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