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
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!