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


Outline

#2

• 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


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

#3


Applications Wind turbines Injection Moulding

Bolt Tensioners Rock splitters

#4


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

#5


LMS.Imagine Lab AMESim®

Geometrical ModelC++, AMESim

FSI Model for Lubricating Gaps

C++ OpenFoam®


Generic Hydraulic System

input output

Global Fluid Dynamic ModelPiston Cylinder

InterfaceCam Piston

Interface

Multi Domain Simulation Tool

#6





C++ OpenFoam®



input output


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

#7






C++ OpenFoam®



input output


InterfaceCam Piston

Interface


#8

Gautham Ramchandran, Pulkit Agarwal and Andrea VaccaEffect of piston grooves on Radial piston pump performance FPIRC 2015 #9




C++ OpenFoam®



input output


InterfaceCam Piston

Interface


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


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

#10

3

. ( ) . . ( ) 0

12 2

b b

b b

tv h hh

p h v h

t t


Exploring Grooved Piston Designs

11

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


Variation of Leakage over one shaft revolution

13


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]

effect of piston grooves in the lubricating performance of ...€¦ · gautham ramchandran, pulkit...

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