Numerical Analysis of underwater body

in Super-cavitating Flow

NUMAP-FOAM 2010 Summer School

Seoul National University, Korea

Sunho Park

Goal of Summer School

ØTo better understand NUMAP-FOAMØTo make solver including cavitation and GGIØTo make solver including cavitation, GGI and six

DOF

2

Strategy

ØMake new Foam in Summer School– Run simplified tutorial

ØValidation and application is later

ØFoam

3

ØFoam

– Cavitation + SRF

– Cavitation + Moving Mesh

– Cavitation + Moving Mesh + 6 DOF

Single Reference Fame

ØCavSRFFoam (Cavitation + Single Reference Frame)

– Consider rotational force in source term

4

Moving Mesh

ØCavDyMFoam (Cavitation + Moving Mesh)– Considering mesh motion before U equation

5

Cp on Hemisphere body

Moving Mesh

ØCavDyMFoam

6

Forced Oscillating Cylinder

Moving Mesh

ØCavDyMFoam

7

GGI Boundary

Moving Mesh and 6 DOF

ØCavDyM6DOFFoam (Cavitation + Moving Mesh + 6 DOF)– Considering 6 DOF before mesh motion – 6 DOF

8

– 6 DOF• Calculate force and moment on body → calculate displacement and rotation angle of each cell on body → patch on point and cell displacement files

Moving Mesh and 6 DOF

ØDomain and Boundary

9

Moving Mesh and 6 DOF

ØMotion generated by force imbalance

10

rasInterDyMFoam

ØrasInterDyMFoam (received from Henrik)– Free surface–Wave generation– Beach boundary

11

– Beach boundary–Moving mesh (GGI)– 6 DOF Motion

Wave tank

ØrasInterDyMFoam–Wave generation and beach boundary work well–Not smooth interface → need high

12

–Not smooth interface → need high resolution interface capturing scheme ?

Floating body with Dam breaking

ØrasInterDyMFoam– 3 DOF motion (2D) with dam breaking problem

13

Floating Bax in Wave Tank

ØrasInterDyMFoam– 3 DOF motion (2D) in wave tank

14

Concluding remark

ØI make my own Foams– cavSRFFoam– cavDyMFoam– CavDyM6DOFFoam

15

– CavDyM6DOFFoam

ØAnd get useful Foam– rasInterDyMFoam

Future Work

ØValidation and Application for my own Foams

ØrasInterDyMFoam + cavFoam

16

ØrasInterDyMFoam + cavFoam–Apply to resistance, propeller openwatertest, self-propulsion, maneuvering performance test of ship