Your SlideShare is downloading. ×
Water wave impact on rigid walls
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×

Introducing the official SlideShare app

Stunning, full-screen experience for iPhone and Android

Text the download link to your phone

Standard text messaging rates apply

Water wave impact on rigid walls

582
views

Published on

Published in: Technology, Business

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
582
On Slideshare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
5
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Water wave impacton rigid wallsBSc. R. Euser06/11/11
  • 2. Contents● About Femto Egineering● Water wave impacts● Simulating water wave impacts using Radioss SPH
  • 3. About femto engineering
  • 4. Company About Software sales Consultancy Engineering agency, Analysis software FE-analysis offering both consultancy and Training Product optimization software for structural analysis (>25 Support Certification employees) Outsourcing More than 12 years experience in CAE Active in BeNeLux and Ukraine Development of client specific software & customization of Femap & Hyperworks Partner of Siemens
  • 5. Activities
  • 6. Customers
  • 7. Offshore projects
  • 8. Water wave impacts
  • 9. Applications Offshore Piping Coastal Automotive
  • 10. About wave impacts● Wave evolution● Surrounding structures● Wave pressure● Air bubbles (aeration)
  • 11. Wave evolution Crest Air pocket Breaking wave Trough Crest Steepening wave Trough Crest Stable wave Trough
  • 12. Surrounding structures● Shape● Roughness● Stiffness
  • 13. Wave pressure t after Pressure impulse P x= ∫ px , t d t t before Worst case Wave Eye Velocity Pressure Velocity
  • 14. Air bubbles (aeration)Positives:● Pressure reduction● DampingNegatives:● Longer impact duration● Larger impact area t = 0.0 ms t = 3.5 ms “Evolution of the air cavity during a depressurized wave impact.” Lugni et al.
  • 15. Simulating water wave impactsusing Radioss SPH
  • 16. Contents● Radioss CFD methods● Radioss SPH approach● SPH Simulations: ● 2D dam break correlation ● 2D water wave impact on a rigid wall● Conclusions
  • 17. Radioss CFD methods ALE SPH Arbitrary Lagrange Eulerian Smooth Particle Hydrodynamics
  • 18. Radioss SPH approach mj f  x i =∑ j  j f x W  r ij , h j { [    ] 2 3 3 2 r 1 r −  r≤h 2 h 3 3 h 2 hW r , h= 3 1 4 h   3 2− r h hr ≤2 h Law Navier-Stokes Radioss SPH Conservation D D i m =− ∇ u =−i ∑ j u ij ∇ W ij of mass Dt Dt j j Conservation of momentum Du Dt 1 =− ∇ T  D ui Dt j  p pj =−∑ m j i i  j  ij ∇ W ij
  • 19. 2D dam break correlation
  • 20. Load case d 0 =0.15 m v gate=1.5 m/s d =0.018 m d0 d 0.38 m 3.55 m Gate velocity 2 1.5 v [m/s] 1 0.5 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 t [s]
  • 21. Radioss SPH model 30,225 particles d particle =0.002 m
  • 22. Results Pressure [Pa] 0 300 600 900 1200 1500 0.219 s 0.281 s 0.343 s =0.010 0.406 s 0.468 s =0.010
  • 23. 2D water wave impact on a rigid wall
  • 24. Goal Measure the effect of particle size on impact pressure
  • 25. Load cases Wave 1 Wave 2 Acceleration vertical plate Acceleration vertical plate 3 10 2 5 1 a [m/s^2] a [m/s^2] 0 0 -1 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 -5 -2 -3 -10 t [s] t [s] Plate Sensors Plate Sensors 20x20 cm 20x20 cm 15 m 15 m 35 m 15 m
  • 26. Models Model Particle size [m] Particle count R1 0.2 3,750 R2 0.04 93,750 Sensors R3 0.02 375,000 Object Element type Plate SPH Detail A Rigid wall Shell Water SPH Sensors RBE2 Water particles Detail A
  • 27. Impact measurement t after Pressure impulse P x= ∫ px ,t d t t before T1 F sensor Discretization P sensor z=∑ z , T DT T0 hsensor d p Load case T0 [s] T1 [s] DT [s] Time interval Wave 1 11.1 11.7 0.001 Wave 2 8.1 8.4 0.001
  • 28. Results – Wave 1 Total Pressure t = 11.1 s t = 11.4 s t = 11.7 s 1.6E+05 1.4E+05 1.2E+05 1.0E+05 R1 R2 P [Pa] 8.0E+04 R3 6.0E+04 4.0E+04 [m/s] R1 2.0E+04 0.0E+00 11.1 11.2 11.3 11.4 11.5 11.6 11.7 t [s] Pressure Impulse 14 12 R2 10 8 R1 z [m] R2 6 R3 4 2 0 0.0E+00 2.0E+04 4.0E+04 6.0E+04 8.0E+04 1.0E+05 PI [Pa s] R3
  • 29. Results – Wave 2 Total Pressure t = 8.1 s t = 8.3 s t = 8.4 s 7.0E+05 6.0E+05 5.0E+05 4.0E+05 R1 R2 P [Pa] 3.0E+05 R3 2.0E+05 [m/s] R1 1.0E+05 0.0E+00 8.1 8.15 8.2 8.25 8.3 8.35 8.4 t [s] Pressure Impulse 14 R2 12 10 R1 8 R2 z [m] 6 R3 4 2 0 0.0E+00 5.0E+04 1.0E+05 1.5E+05 2.0E+05 PI [Pa s] R3
  • 30. Results discussion● Fluid velocity● Fluid pressure● Total pressure (pressure peaks)● Pressure impulse
  • 31. Conclusions● Wave impacts: ● Wave evolution ● Surrounding structures ● Impact pressure ● Aeration● Radioss SPH simulations: ● 2D Dam Break correlation ● 2D wave impacts
  • 32. molslaan 1112611 rk delftT +31 (0) 15 285 05 80 www.femto.nlF +31 (0) 15 285 05 81 info@femto.nl