F. Xavier Borràs*1, Jan Ukonsaari2 and Andreas Almqvist1
1Luleå University of Technology, Division of Machine Elements, Luleå, Sweden; 2Vattenfall, Vattenfall Research and Development AB, Luleå, Sweden.*Corresponding author: Luleå University of Technology, 97 187 Luleå (Sweden), [email protected]
Multiphysics Modelling of Spring-Supported Thrust Bearings for
Hydropower Applications
Thrust bearings are commonly used in hydroelectric power plants. These bearings are required to support the shafts of the turbines.
1.1) Thrust Bearings
THRUST BEARING
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3
3. Collar
2. Fluid
1. Pad
The relative motion between the collar and the pads generates a pressure distribution.
COLLAR
PAD SUPPORT
External Load
Pressure distribution
p
1.2) HOW does it work
Fluid Velocity Field
U
GAP GEOMETRY • Elastic Deformation• Thermal Expansion
• Tilting
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2
3
Gap Height h
• The pad is supported by a spring mattress.
• There is not a defined pivot point.
1.3) Spring-Supported
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2
3
A.) PAD
B.) COLLAR
C.) FLUID
2) Model
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2
3
2.1) Physics AppliedCOLLAR
FLUID
PAD
MM
HTf
HTs
SM
LS
Heat Transfer in Solids
Solid Mechanics
Moving Mesh
(mesh deformation)
Lubricant Shell
Heat Transfer in Fluids
SM
HTs
HTf
MM
LS
SM
HTs
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2
3
2.2) Model CouplingCOLLAR
FLUID
PAD
pf
pf
pf
u,v,z
hwall
u,v,z
T
T
T
X,Y,Z
hchannel
u,v,z
T
u,v,zSM
HTs
HTf
MM
LS
SM
HTs
1
2
3
OUTPUTS
Pressure on the Gap
PADDeformation
Temperature
COLLARDeformation
Temperature
FLUIDFilm Thickness
Temperature
Power Losses
INPUTSShaft Angular Velocity
External Load Applied
Bath Temperature
Geometry Parameters
Material ProprietiesSprings Pattern Characteristics
Spring-Supported Thrust Bearing Model
3) RESULTS: Global Scheme
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3
HOW does it work? Springs
3.1) ResultsPressure on the Gap
Fluid Velocity Field
Pad Temperature
Fluid Film Thickness
Collar Displacement
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2
3
3.2) Applications of the Model
• Varying operating conditions:a) Loadb) Angular Velocityc) Bath Temperatured) Springs Patterns
• Test different kinds of lubricants.• Test different compounds materials.• Test shape improvements.
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2
3
F. Xavier Borràs*1, Jan Ukonsaari2 and Andreas Almqvist1
1Luleå University of Technology, Division of Machine Elements, Luleå, Sweden; 2Vattenfall, Vattenfall Research and Development AB, Luleå, Sweden.*Corresponding author: Luleå University of Technology, 97 187 Luleå (Sweden), [email protected]
Multiphysics Modelling of Spring-Supported Thrust Bearings for
Hydropower Applications