Effect of Piston Grooves in the Lubricating Performance of ...€¦ · Gautham Ramchandran, Pulkit...
Transcript of Effect of Piston Grooves in the Lubricating Performance of ...€¦ · Gautham Ramchandran, Pulkit...
Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
Effect of Piston Grooves in the Lubricating Performance of an Ultra-High Pressure Radial Piston Pump
Gautham Ramchandran (presenter) Pulkit Agarwal
Prof. Andrea Vacca
Maha Fluid Power Research CenterSchool of Mechanical Engineering
Purdue University, USA 14th October 2015
Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
Outline
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• Introduction to Radial Piston Pumps
• The Multi-Domain Simulation Tool
• The Solution Algorithm
• Exploring Grooved Piston Designs
• The Hydrodynamic Effect
• Results and Discussion
• Conclusions and Future Work
Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
Radial Piston Pumps
Important Features:-
Very high Pressures can be generated.
Low noise level
Can withstand very high loads at low speeds.
Rotating Cam type Rotating Cylinder type
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Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
Applications Wind turbines Injection Moulding
Bolt Tensioners Rock splitters
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Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
Rotating CamPump Parts:
Piston-Cylinder interface in radial piston machines
Main functions of the gap
+ Sealing
+ Bearing loads
Main source of power losses
- Mechanical Losses
- Volumetric Losses
O’O
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Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
LMS.Imagine Lab AMESim®
Geometrical ModelC++, AMESim
FSI Model for Lubricating Gaps
C++ OpenFoam®
LMS.Imagine Lab AMESim®
Generic Hydraulic System
input output
Global Fluid Dynamic ModelPiston Cylinder
InterfaceCam Piston
Interface
Multi Domain Simulation Tool
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Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
LMS.Imagine Lab AMESim®
Geometrical ModelC++, AMESim
FSI Model for Lubricating Gaps
C++ OpenFoam®
LMS.Imagine Lab AMESim®
Generic Hydraulic System
input output
Global Fluid Dynamic ModelPiston Cylinder
InterfaceCam Piston
Interface0
10
20
30
0 45 90 135 180 225 270 315 360Gap
Len
gth
/mm
Angle/°
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0 45 90 135 180 225 270 315 360
Vel
oci
ty/
m/s
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Multi Domain Simulation Tool
Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
LMS.Imagine Lab AMESim®
Geometrical ModelC++, AMESim
FSI Model for Lubricating Gaps
C++ OpenFoam®
LMS.Imagine Lab AMESim®
Generic Hydraulic System
input output
Global Fluid Dynamic ModelPiston Cylinder
InterfaceCam Piston
Interface
Multi Domain Simulation Tool
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Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015 #9
LMS.Imagine Lab AMESim®
Geometrical ModelC++, AMESim
FSI Model for Lubricating Gaps
C++ OpenFoam®
LMS.Imagine Lab AMESim®
Generic Hydraulic System
input output
Global Fluid Dynamic ModelPiston Cylinder
InterfaceCam Piston
Interface
Multi Domain Simulation Tool
CN
Cf
TN
Tf
DK
F =Friction between cam and piston
F =Normal contact force by cam on the piston
F =Normal force by fluid film
F =Viscous friction
F =Press. force from disp. chamber
All forces act along x-y plane
X
Z
Y
Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
Fluid Film domain
x
Y
O
gapl
1e2e
bxax
Z
Piston micro-motion with 2 DOF
'A
A
2 11
( )( ) ( )m A
gap
e ey x x x e
l
Sec A-A
Y
Z
Piston
Cylinder
C1e
h
( ) 0mz x
2 2 2
C
P
( , ) ( ( )) cosc mh x R sin y x R
R h
Boundary Conditions
A P=0 (open to the drain)
B P=Disp. chamber press.
C, D Cyclic
2 CR
( , )P x y
O
x
y
A
BC
D
• Discretized using finite volume method• Reynolds equation solved to find pressure at each cell
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3
. ( ) . . ( ) 0
12 2
b b
b b
tv h hh
p h v h
t t
Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
Exploring Grooved Piston Designs
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No Grooves Case A Case B Case C
Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015 12
RESULTS
Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
Variation of Leakage over one shaft revolution
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Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015
Variation of Viscous Friction Power Loss over one shaft revolution
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Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015 15
THANK YOU
Gautham Ramchandran, Pulkit Agarwal and Andrea Vacca
MAHA Fluid Power Research CenterPurdue University, West Lafayette (USA)
Email: [email protected]