Slide 1

ERCOFTAC MEETING

Faculty of Mechanical Engineering and Naval Architecture University of Zagreb, 2009

Numerical Modelling of Cavitation Numerical Modelling of Cavitation ErosionErosion

Matevž Dular Olivier Coutier-Delgosha

matevz.dular@fs.uni-lj.si

Slide 2Work overview

NUMERICAL PREDICTION OF CAVITATION EROSION

Numerical simulation Model development

Simulation validation Model validation

PIV, pressure waves Erosion measurements

Slide 3Numerical simulation

URANS simulation

k- ε RNG turbulence model

Barotropic cavitation model

Slide 4Experiment – PIV...1

Slide 5Experiment – PIV...2

M. Dular et al., European Journal of Mechanics– B/Fluids, Volume 26(5), p. 688-705

Slide 6Experiment – pressure waves

Slide 7Experiment – erosion...1

Slide 8Experiment – erosion...2

Slide 9Erosion model

CFD Erosion model

Slide 10

Micro jet formation

Erosion model

Pit formation

ργ v

jetpp

v−

= 297.8

⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛

⎟⎟⎠

⎞⎜⎜⎝

⎛+−=

−n

y

l

ycrit B

ppv

1

11ρ

( ) defcritjetpit tvvd ⋅−=

l

jetdef c

rt =

( )2pit

2pitpit d7.26rA ππ ==

tA

AA

ref

t

0tpit

damτ

⋅=∑

=

Slide 11Solution algorithm

Slide 12Results – predicting damage

0 20 40 60 80 100 1200

0.5

1

1.5

2

2.5

3

3.5

x (mm)

Slide 13Results – predicting damage

Slide 14

ONE OF THE FIRST IMPLEMENTATIONS OF THE CAVITATION EROSION MODEL INTO A CFD CODE WAS SHOWN

Conclusions

A PLAUSIBLE CORRELATION TO THE EXPERIMENTAL DATA WAS ACHIEVED

CORRECT PRESSURE WAVE PREDICTION IS ESSENTIAL FOR A SUCCESSFUL CAVITATION EROSION PREDICTION!