Incoming and Outgoing Shipments in 1 STEP Using Odoo 17
Elango doss-2009
1. Simulation and Validation
of
Piton Type Wave maker by CFD
Muniyandy ELANGOVAN
and
Anant LAL
Indian Register of Shipping
Mumbai
INDIA
2. • Simulate the Numerical Wave Tank
• Generate the Regular Wave
• Study Wave Damping
• Validation
• Estimate - Ship Motion in Sea State by CFD
• Hydrodynamics Forces
• Wave Pattern
3. Performance of Ship Needed Data
Passenger Comfort Ship Motion
Accurate estimation of forces for Hydrodynamic Forces
structural analysis
Achieve Required Speed Resistance & Wave Pattern
Ship Design
Model Test Ship Construction
(Hull)
CFD - Analysis
5. SEAKEEPING ESTIMATIONS
Towing Tank Towing Tank
w/o Wave Maker with Wave Maker
• Hydrodynamic Forces
• Exciting Forces
• Ship Motions
Wave Maker
* Piston Type
* Flap Type
* Plunger Type
6. PISTON TYPE WAVE MAKER
Tank Top
End
s Wave Profile
Wall
Piston
hw = he
Ap Beach
Piston_displacement @ Ap sin (w t)
7. RANSE Solver Ansys CFX-11.0, based on Finite Volume Method (FVM)
Multiphase (Water and Air) using VOF method
Transient simulations
Governing Equations:
continuity, momentum, volume fraction and Turbulence model
Boundary Conditions:
Bottom, Beach slope and end wall as wall with no-slip condition
Tank Top
End wall
Flap
Beach
Side Wall
Bottom
3D view of Wave Tank
8. GRID AND TURBULANCE STUDY
Cases: Type: No. of Elements:
Case1 Coarse 5,115
Case2 Normal 9,246
Case3 Fine 15,921
9. Test cases:
hw t Ap/t Ap
(m) (s) (m/s) (m)
0.1 1.5 0.0625 0.10
0.25 2.0 0.15
0.75 2.5 0.20
1.00 4.0
1.25 4.5
5.0
hw = water height
t = Time period
Ap = Piston Stroke Length
Ap/t = constant velocity
10. Locations of Wave Elevation Measurement
Points Location (x in m)
2D Schematic view of Wave Tank P1 1
P2 2
P3 3
P4 4
P5 28
P6 30.5
P7 32
P8 33.5
11. Relation between stroke length, water
height and wave height is given by[8]
sinh khw + khw
S=H
2(cosh khw − 1)
S = stroke length
H = wave height,
hw = water height of the tank.
K = Wave number
S=2Af (Flap stroke length)
[8] Robert G. Dean and Robert A. Dalrymple
“Water wave mechanics, for Engineers and scientist”
12. BEACH ANALYSIS
Tank Top
End
s Wave Profile Wall
1:3 Beach
1:6 1:4.5
13. BEACH ANALYSIS
Wave elevation at Locations P1 and P4
Max. damping for 1:3 slope
14. CFD => RESULTS and ANALYSIS
Dependency: STROKE LENGTH
Wave height and wave length are proportional to STROKE LENGTH
15. CFD => RESULTS and ANALYSIS
Dependency: WATER HEIGHT
Wave height and wave length are proportional to WATER HEIGHT
22. CONCLUSIONS
Regular waves were generated using CFD technique
Computed results are in good agreement with wave maker theory
Results can be used for establishing an experimental wave-maker by
knowing the limitations
CFD simulations can effectively replace the experimental Wave Tank
We can see a beautiful ship which is above the water level. As a designer or researcher, we look below the water level i.e., hull. Which is like a brain for a man .
Before going to any topic, we must ask the questions our self like what is it, why is it and how doest it. First let us the see the aim/purpose. Passenger comfort: This is the most important in any ship. This can be controlled if we can calculate the rolling motion of the ship. Next Accurate estimation of forces for structural analysis: This is important when we design the structure. Here we need the hydrodynamic forces. Next Achieve Required Speed: This can be done if we can get the resistance of the hull when it is moving. The last but not least, cost effective. If we can achieve all above then it will be cost effective. Now we come to Needed data: ship motion, hydrodynamic forces and resistance & wave motion all required to achieve our purpose. How do we get those needed data. Now we are getting through the model test for the particular ship model. Let me explain the ship construction process to have better idea. For any kind of ship, we need design the hull and it has to go for model test. In the model we will be getting these data and it will be decided whether to change the design or not. If change is required then it will come back to hull design and then model test again. If the hull is completely satisfied then we go for further steps i.e., preparation of class drawing and construction. In this process, my reseach can replace the model test. Now let us compare the experiment and numerical analysis.
