Enhancing Heat Transfer Performance and Oxidation ... Library/Events/2017/utsr/posters... ·...
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Wall Jet Coupons Lattice Coupons 0.1 in 0.154 in Unit Cell Chevron type jets Slot type jets Additive Manufacturing Test Rigs Enhancing Heat Transfer Performance and Oxidation Resistance of Near Surface Cooling Channels using Additive Manufacturing Technologies Sarwesh Narayan Parbat, Zheng Min, Li Yang, Minking Chyu Department of Mechanical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 10mm Phases of ODS NSCC Fabrication h Channel parameters Test Coupons Heat Transfer Oxidation Characterization of AM printed ODS Coupons Introduction Connectivity: (a) Lcase1: isolated units (b) Lcase2: interconnected units. (a) (b) Examples of lattice and unit cells Lcase1 coupon with isolated units. Channels embedded in ODS coupons ODS on Inconel substrate (a) Without channels (b) With channels (b) (a) High Nu enhancement for AM printed coupons with wall jets and lattice geometries. Heat transfer increased with increasing BR and decreasing P for wall jet coupons. Spanwise averaged Nu/Nu max for channel with wall jets and normally impinging jets at channel Re = 3000. Wall jets have much higher uniformity across target plate. Velocity Field Impingement Wall Jets Schematic for Test Setup With a target to push gas turbine efficiencies to 65%, the turbine inlet temperature is set to exceed 1700 o C. As a result, there is a need to provide enhanced cooling and oxidation protection to the hot gas path components to ensure they are within their operational envelope. Additive manufacturing technologies provide unique opportunity to explore complex design spaces which can meet these challenges. There are two parts of the current research effort: • To provide uniform and highly augmented heat transfer using novel wall jet and lattice geometries in conjunction with near surface cooling channels (NSCC) fabricated through additive manufacturing (AM). • To enhance oxidation resistance of hot gas path components by using oxide dispersion strengthened(ODS) powder for fabrication. • Explore new wall jet and lattice geometries. • Fabricate lattice and wall jet coupons with ODS. • Conduct high temperature tests on ODS coupons. No crossflow effect for wall jets. Low temperature coolant near target wall Future Work Advantage of Wall Jet Over Impingement Cooling Upstream Pointing Chevrons Comparison Between Different Geometries Downstream Pointing Chevrons Enhancement in Chevron Wall Jets with Streamwise Vortices Wall jet formed when coolant passes through the slots. AM Wall Jets, Lattice Type Extended Surface ODS Powder AM Process High heat transfer and oxidation resistant NSCC EOSM290: Direct Metal Laser Sintering (DMLS) LENS450: Direct Metal Deposition (DMD) Long term stability of protective oxide layer Slot Zeiss Sigma 500 VP SEM Thermal Cyclic and Oxidation Tests Al 2 O 3 Target Wall 0 0.2 0.4 0.5 0.8 1 Target Wall Bottom End Wall Recirculation Partial Impingement 0 0.25 0.5 0.75 1 Ongoing research work showed the formation process of protective oxide layer for both inner side and outer side of ODS channels. Continuous Al 2 O 3 layer formation T g , h g (Hot Gas Path) T c , h c (Internal Cooling Technique) Superalloy ODS Superalloy ODS T g , h g (Hot Gas Path) T c , h c (Internal Cooling Technique) T g , h g (Hot Gas Path) T c , h c (Internal Cooling Technique) ODS Stable adhesion between ODS coating layer and substrate Impingement Slot Wall Jets BR 0.75 BR 0.65 BR 0.5 Vortices near the side. Vortices at the center. Vortices diminish after first jet. Velocity Streamline Temperature Contour Bottom End Wall Wall Jet Overview Steady State Heat Transfer Rig ODS deposited on superalloy using LENS 450 Target Plate Channels Separation Walls Slots Features • Coolant flows through the slots and forms wall jets. • Low temperature and high speed flow located near target surface provides uniform cooling. Features • High surface area for heat transfer • Promote turbulence ExOne M-Flex: Binder Jetting Printers Source: optomec.com Source: exone.com Source: exone.com Source: Lu, T. J., Xu, F., Wen, T. “Thermo-Fluid Behaviour of Periodic Cellular Metals L *DMLS * Nu 0 from Gnielinski Correlation 0 0.25 0.5 0.75 1
Transcript of Enhancing Heat Transfer Performance and Oxidation ... Library/Events/2017/utsr/posters... ·...
Wall Jet Coupons
Lattice Coupons
0.1
in
0.154 in
Unit Cell
Chevron type jetsSlot type jets
Additive Manufacturing
Test Rigs
Enhancing Heat Transfer Performance and Oxidation Resistance of Near Surface Cooling Channels using Additive Manufacturing Technologies
Sarwesh Narayan Parbat, Zheng Min, Li Yang, Minking ChyuDepartment of Mechanical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania
10mm
Phases of ODS NSCC Fabricationh
Channel parameters
Test Coupons
Heat Transfer Oxidation Characterization of AM printed ODS Coupons
Introduction
Connectivity: (a) Lcase1: isolated units (b) Lcase2: interconnected
units.
(a) (b)
Examples of lattice and unit cells Lcase1 coupon with isolated units.
Channels embedded in ODS coupons
ODS on Inconel substrate(a) Without channels(b) With channels(b)
(a)
High Nu enhancement for AM printed coupons with wall jets and lattice geometries. Heat transfer increased with increasing
BR and decreasing P for wall jet coupons.
Spanwise averaged Nu/Numax for channel with wall jets and normally impinging jets at channel Re = 3000. Wall jets have much higher
uniformity across target plate.
Velocity Field
ImpingementWall Jets
Schematic for Test Setup
With a target to push gas turbine efficiencies to 65%, the turbine inlet temperature is set to exceed 1700o C. As a result, there is a need to provide enhanced cooling and oxidation protection to the hot gas path components to ensure they are within their operational envelope. Additive manufacturing technologies provide unique opportunity to explore complex design spaces which can meet these challenges.There are two parts of the current research effort: • To provide uniform and highly augmented heat transfer using
novel wall jet and lattice geometries in conjunction with near surface cooling channels (NSCC) fabricated through additive manufacturing (AM).
• To enhance oxidation resistance of hot gas path components by using oxide dispersion strengthened(ODS) powder for fabrication.
• Explore new wall jet and lattice geometries.• Fabricate lattice and wall jet coupons with ODS.• Conduct high temperature tests on ODS coupons.
No crossflow effect for wall jets.
Low temperature coolantnear target wall Future Work
Advantage of Wall Jet Over Impingement Cooling
Upstream Pointing Chevrons
Comparison Between Different Geometries
Downstream Pointing Chevrons
Enhancement in Chevron Wall Jets with Streamwise Vortices
Wall jet formed when coolant passes through the slots.
AM
Wall Jets, Lattice Type Extended
Surface
ODS Powder AM Process
High heat transfer and oxidation resistant NSCC
EOSM290: Direct Metal Laser Sintering (DMLS)LENS450: Direct Metal Deposition (DMD)
Long term stability of protective oxide layer
Slot
Zeiss Sigma 500 VP SEM
Thermal Cyclic and Oxidation Tests
Al2O3
Target Wall
0 0.2 0.4 0.5 0.8 1
Target Wall
Bottom End WallRecirculation
Partial Impingement
0 0.25 0.5 0.75 1
Ongoing research work showed the formation process of protective oxide layer for both inner side and outer side of ODS channels.
Continuous Al2O3 layer formation
Tg, hg (Hot Gas Path)
Tc, hc (Internal Cooling Technique)
Superalloy
ODS
Superalloy
ODS
Tg, hg (Hot Gas Path)
Tc, hc (Internal Cooling Technique)
Tg, hg (Hot Gas Path)
Tc, hc (Internal Cooling Technique)
ODS
Stable adhesion between ODS coating layer and
substrate
Impingement
Slot Wall Jets
BR 0.75BR 0.65BR 0.5
Vortices near the side.
Vortices at the center.
Vortices diminish after first jet.
Velocity Streamline Temperature ContourBottom End Wall
Wall Jet
Overview
Steady State Heat
Transfer Rig
ODS deposited on superalloyusing LENS 450
Target Plate
Channels
Separation Walls
Slots
Features• Coolant flows through
the slots and forms wall jets.
• Low temperature and high speed flow located near target surface provides uniform cooling.
Features• High surface area for heat transfer• Promote turbulence
ExOne M-Flex: Binder
Jetting Printers
Source: optomec.com
Source: exone.com
Source: exone.com
Source: Lu, T. J., Xu, F., Wen, T. “Thermo-Fluid Behaviour of Periodic Cellular Metals
L
*DMLS
*
Nu0 from GnielinskiCorrelation
0
0
.25
0
.5
0.7
5
1
