Investigations of Trenched Film Hole Orientation Angle on Film Cooling Effectiveness
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V.G Krishna Anand
und
K.M Parammasivam
Abstract
The effect of altering the orientation angle of trenched film hole on film cooling effectiveness (ƞ) is analyzed through numerical investigation. The film holes were oriented at 6 different angles viz., 0°, 30°, 45°, 90°, 135° and 180° with a fixed inclination angle 30° and with a pitch to diameter (P/D) ratio 5.The length and depth of the trench embedding the film hole are fixed at 3D and 0.75D respectively. Three different blowing ratios M=0.5, 1 and 1.5 were studied. Results from the study reveal that changing the orientation angle of film hole with in trench offered a considerable improvement on ƞ from near film hole region to far downstream location on test surface. For a low blowing ratio of 0.5, the film cooling effectiveness distribution changes with respect to film hole orientation angle and higher ƞ zones are distributed along the corresponding film hole orientation angle. The film hole oriented at 90° with respect to stream wise direction delivered highest ƞ at all three different blowing ratios due to better lateral spreading and uniform coverage of injected coolant. Except near film hole region, 30° and 45° hole orientation produced uniform lateral effectiveness compared to 0° hole orientation.
Nomenclature
- X/D
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Non dimensional distance along mainstream direction
- Y/D
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Non dimensional distance from wall surface in vertical direction
- Z/D
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Non dimensional distance along lateral direction
- D
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Diameter of film cooling hole, mm
- ℓ
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Length of trench, mm
- d
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Depth of trench, mm
- α
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Inclination angle of film cooling hole,°
- β
-
Orientation angle of film cooling hole, °
- L
-
Length of film cooling hole, mm
- ƞ
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Local film cooling effectiveness
- ƞ̅
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Laterally averaged film cooling effectiveness
- T∞
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Temperature of mainstream air flow, k
- Taw
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Temperature of wall at adiabatic condition, k
- Tc
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Temperature of injected coolant, k
- M
-
Blowing Ratio
- ρc
-
Density of film cooling air, Kg/m3
- ρ∞
-
Density of mainstream air, Kg/m3
- uc
-
Velocity of film cooling air, m/sec
- u∞
-
Velocity of mainstream air, m/sec
- P
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Pitch distance between film cooling holes, mm
- L/D
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Length to diameter ratio of film cooling hole
- P/D
-
Pitch to diameter ratio of film cooling hole
Acknowledgement
The first author gratefully acknowledges Department of Science and Technology, Government of India for awarding DST INSPIRE Fellowship.
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© 2017 Walter de Gruyter GmbH, Berlin/Boston
Artikel in diesem Heft
- Frontmatter
- Original Research Articles
- Investigations of Trenched Film Hole Orientation Angle on Film Cooling Effectiveness
- Jet Flow Control Using Semi-Circular Corrugated Tab
- Simulation of Use-Related Multi-Parameter Load Spectrum Based on Principal Component Analysis
- Characterization of Tandem Airfoil Configurations of Axial Compressors
- Research on Suppressing Vibration of Mistuning Cyclic-Periodic Structure
- Research on Power Regulation Schedule Control System for Turboprop Engine
- Enhancement of Full Coverage Film Cooling Effectiveness with Mixed Injection Holes
- CFD Analysis and Experimental Validation of the Flow Field in a Rib Roughed Turbine Internal Cooling Channel
- Perforated Wall in Controlling the Separation Bubble Due to Shock Wave –Boundary Layer Interaction
- Calculating Endogenous and Exogenous Exergy Destruction for an Experimental Turbojet Engine
- One-equation turbulence models applied to practical scramjet inlet
Artikel in diesem Heft
- Frontmatter
- Original Research Articles
- Investigations of Trenched Film Hole Orientation Angle on Film Cooling Effectiveness
- Jet Flow Control Using Semi-Circular Corrugated Tab
- Simulation of Use-Related Multi-Parameter Load Spectrum Based on Principal Component Analysis
- Characterization of Tandem Airfoil Configurations of Axial Compressors
- Research on Suppressing Vibration of Mistuning Cyclic-Periodic Structure
- Research on Power Regulation Schedule Control System for Turboprop Engine
- Enhancement of Full Coverage Film Cooling Effectiveness with Mixed Injection Holes
- CFD Analysis and Experimental Validation of the Flow Field in a Rib Roughed Turbine Internal Cooling Channel
- Perforated Wall in Controlling the Separation Bubble Due to Shock Wave –Boundary Layer Interaction
- Calculating Endogenous and Exogenous Exergy Destruction for an Experimental Turbojet Engine
- One-equation turbulence models applied to practical scramjet inlet
