Flowfield measurements for film-cooling holes with expanded exits

Karen Ann Thole, M. Gritsch, A. Schulz, S. Wittig

Research output: Chapter in Book/Report/Conference proceedingConference contribution

18 Citations (Scopus)

Abstract

One viable option to improve cooling methods used for gas turbine blades is to optimize the geometry of the film-cooling hole. To optimize that geometry, effects of the hole geometry on the complex jet-in-crossflow interaction need to be understood. This paper presents a comparison of detailed flowfield measurements for three different single, scaled-up, hole geometries all at a blowing ratio and density ratio of unity. The hole geometries include a round hole, a hole with a laterally expanded exit, and a hole with a forward-laterally expanded exit. In addition to the flowfield measurements for expanded cooling hole geometries being unique to the literature, the testing facility used for these measurements was also unique in that both the external mainstream Mach number (Mato = 0.25) and internal coolant supply Mach number (Mac = 0.3) were nearly matched. Results show that by expanding the exit of the 600ling holes, the penetration of the cooling jet as well as the inienie Shear regions are significantly reduced relative to a round fibre:Although the peak turbulence levels for all three hole geometries was nominally the same, the source of that turbulence was different. The peak turbulence level for both expanded holis was located at the exit of the cooling hole resulting from the expansion angle being too large. The peak turbulence level for the round hole was located downstream of the hole exit where the velocity gradients were very large.

Original languageEnglish (US)
Title of host publicationHeat Transfer; Electric Power; Industrial and Cogeneration
PublisherWeb Portal ASME (American Society of Mechanical Engineers)
ISBN (Electronic)9780791878750
DOIs
StatePublished - Jan 1 1996
EventASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1996 - Birmingham, United Kingdom
Duration: Jun 10 1996Jun 13 1996

Publication series

NameASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1996
Volume4

Other

OtherASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1996
CountryUnited Kingdom
CityBirmingham
Period6/10/966/13/96

Fingerprint

Cooling
Geometry
Turbulence
Mach number
Blow molding
Coolants
Turbomachine blades
Gas turbines
Fibers
Testing

All Science Journal Classification (ASJC) codes

  • Energy Engineering and Power Technology
  • Fuel Technology
  • Nuclear Energy and Engineering
  • Aerospace Engineering
  • Mechanical Engineering

Cite this

Thole, K. A., Gritsch, M., Schulz, A., & Wittig, S. (1996). Flowfield measurements for film-cooling holes with expanded exits. In Heat Transfer; Electric Power; Industrial and Cogeneration (ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1996; Vol. 4). Web Portal ASME (American Society of Mechanical Engineers). https://doi.org/10.1115/96-GT-174
Thole, Karen Ann ; Gritsch, M. ; Schulz, A. ; Wittig, S. / Flowfield measurements for film-cooling holes with expanded exits. Heat Transfer; Electric Power; Industrial and Cogeneration. Web Portal ASME (American Society of Mechanical Engineers), 1996. (ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1996).
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abstract = "One viable option to improve cooling methods used for gas turbine blades is to optimize the geometry of the film-cooling hole. To optimize that geometry, effects of the hole geometry on the complex jet-in-crossflow interaction need to be understood. This paper presents a comparison of detailed flowfield measurements for three different single, scaled-up, hole geometries all at a blowing ratio and density ratio of unity. The hole geometries include a round hole, a hole with a laterally expanded exit, and a hole with a forward-laterally expanded exit. In addition to the flowfield measurements for expanded cooling hole geometries being unique to the literature, the testing facility used for these measurements was also unique in that both the external mainstream Mach number (Mato = 0.25) and internal coolant supply Mach number (Mac = 0.3) were nearly matched. Results show that by expanding the exit of the 600ling holes, the penetration of the cooling jet as well as the inienie Shear regions are significantly reduced relative to a round fibre:Although the peak turbulence levels for all three hole geometries was nominally the same, the source of that turbulence was different. The peak turbulence level for both expanded holis was located at the exit of the cooling hole resulting from the expansion angle being too large. The peak turbulence level for the round hole was located downstream of the hole exit where the velocity gradients were very large.",
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Thole, KA, Gritsch, M, Schulz, A & Wittig, S 1996, Flowfield measurements for film-cooling holes with expanded exits. in Heat Transfer; Electric Power; Industrial and Cogeneration. ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1996, vol. 4, Web Portal ASME (American Society of Mechanical Engineers), ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1996, Birmingham, United Kingdom, 6/10/96. https://doi.org/10.1115/96-GT-174

Flowfield measurements for film-cooling holes with expanded exits. / Thole, Karen Ann; Gritsch, M.; Schulz, A.; Wittig, S.

Heat Transfer; Electric Power; Industrial and Cogeneration. Web Portal ASME (American Society of Mechanical Engineers), 1996. (ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1996; Vol. 4).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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Thole KA, Gritsch M, Schulz A, Wittig S. Flowfield measurements for film-cooling holes with expanded exits. In Heat Transfer; Electric Power; Industrial and Cogeneration. Web Portal ASME (American Society of Mechanical Engineers). 1996. (ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1996). https://doi.org/10.1115/96-GT-174