Influence of Laser Drilling Imperfection on Film Cooling Performances

Jovanovic, M. B.; Lange, H. C. de; Steenhoven, Anton A. van

doi:10.1115/gt2005-68251

Cited by 13 publications

(11 citation statements)

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“…These structures affect the film cooling process (see Jovanović et al, 2005). The largest are the lee, windward vortices and a counter rotating pair known also as kidney vortices.…”

Section: Integral Curvesmentioning

confidence: 98%

“…The experiments were conducted in a water channel at the Technische Universiteit Eindhoven (Eindhoven University of Technology) (for details see Jovanović et al, 2005). A plexiglas flat plate (2400 Â 565 mm) is placed in the test section.…”

Section: Experimental Set-upmentioning

confidence: 99%

“…This vortex reduces the film cooling effectiveness. The influence of the hole imperfection, located inside an inclined hole, on the flow field is reported in Jovanović et al (2005). They found that the imperfection amplifies lee and windward vortices and leads to a bursting mechanism.…”

Section: Introductionmentioning

confidence: 97%

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Effect of hole imperfection on adiabatic film cooling effectiveness

Jovanovic

Lange

Steenhoven

2008

International Journal of Heat and Fluid Flow

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“…These structures affect the film cooling process (see Jovanović et al, 2005). The largest are the lee, windward vortices and a counter rotating pair known also as kidney vortices.…”

Section: Integral Curvesmentioning

confidence: 98%

Section: Experimental Set-upmentioning

confidence: 99%

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Effect of hole imperfection on adiabatic film cooling effectiveness

Jovanovic

Lange

Steenhoven

2008

International Journal of Heat and Fluid Flow

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“…Experimental studies have shown the detrimental effects on adiabatic effectiveness of in-hole blockages in cylindrical film cooling holes. Jovanovic et al [3] found significant changes in the flowfield of a cylindrical hole blocked with a half torus shaped blockage, which is commonly found in the melt ejection during laser drilling. Large decreases in film cooling effectiveness were also found, with the decreases being larger at low velocity ratios.…”

Section: Relevant Past Studiesmentioning

confidence: 99%

Blockage Effects From Simulated Thermal Barrier Coatings for Cylindrical and Shaped Cooling Holes

Whitfield

Schroeder

Thole

et al. 2015

Journal of Turbomachinery

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Film cooling and sprayed thermal barrier coatings (TBCs) protect gas turbine components from the hot combustion gas temperatures. As gas turbine designers pursue higher turbine inlet temperatures, film cooling and TBCs are critical in protecting the durability of turbomachinery hardware. One obstacle to the synergy of these technologies is that TBC coatings can block cooling holes when applied to the components, causing a decrease in the film cooling flow area thereby reducing coolant flow for a given pressure ratio (PR). In this study, the effect of TBC blockages was simulated on film cooling holes for widely spaced cylindrical and shaped holes. At low blowing ratios for shaped holes, the blockages were found to have very little effect on adiabatic effectiveness. At high blowing ratios, the area-averaged effectiveness of shaped and cylindrical holes decreased as much as 75% from blockage. The decrease in area-averaged effectiveness was found to scale best with the effective momentum flux ratio of the jet exiting the film cooling hole for the shaped holes.

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“…Imperfections may also be produced during manufacturing of the holes and refurbishing of the holes after long hours of flight. It is known that imperfections in a hole may reach even 25% of hole diameter [3].…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation of Partial Blockage Effect on Film Cooling Effectiveness

Pan

Zhang

Ke-nan

2014

Mathematical Problems in Engineering

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Three-dimensional numerical calculation was performed to investigate the effects of partial blockage inside cylindrical film holes on the film cooling effectiveness over a flat plate. Five blockage ratios ranged from 0.1 to 0.5 and a series of blockage positions were considered under the blowing ratios of 0.3–1.5. It is found that the blockage position has a significant influence on mainstream-coolant jet interaction. The partial blockage located at the leading edge of coolant-hole exit mitigates the primary vortices due to mainstream-coolant jet interaction. The coolant jet penetration along vertical direction is suppressed and the peak velocity along streamwise direction is augmented under the action of partial blockage at the upstream side of film holes, providing an increment of film cooling effectiveness, especially under high blowing ratio. While the partial blockages located at the trailing or lateral edges of coolant-hole exit weaken the film cooling effectiveness. In relation to the partial blockage located in the vicinity of coolant-hole exit, the partial blockage located in the vicinity of coolant-hole inlet or middle has less impaction on the film cooling effectiveness under low blowing ratio.

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Influence of Laser Drilling Imperfection on Film Cooling Performances

Cited by 13 publications

References 0 publications

Effect of hole imperfection on adiabatic film cooling effectiveness

Effect of hole imperfection on adiabatic film cooling effectiveness

Blockage Effects From Simulated Thermal Barrier Coatings for Cylindrical and Shaped Cooling Holes

Numerical Investigation of Partial Blockage Effect on Film Cooling Effectiveness

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