Ship:
Predicting ship hydrodynamics. l Ship wave interaction. l Ship resistance, propulsion, hull optimization. l Maneuvering. l Seakeeping. l Autopilot, controllers, multi-ship interactions, etc. l Simulation under the condition of mooring system. l
Hydrodynamic
coefficients calculation serving for NDA (Nonlinear Dynamics Approaches) simulation. l Others. |
Validations & Applications
Case1: Free Surface Steady Flow around a Surface Combatant (3-D DTMB 5512 Ship with Deck, Fixed Sinkage and Trim)
Computation conditions
Resistance coefficients for DTMB 5512 ship
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Case2:
Sinkage and Trim (DTMB 5415 Ship)
Computation conditions l Ship predicted motion of 2DOF: heave and pitch. l Fr=0.41, Re= 1.35E+07 (ship length=5.72m). l Dimensionless inputs: radius of gyration rg_y=0.25, weight coefficient =0.237,static area=0.074, gravity center (0.5054,0,-0.0097). l Grid nodes: 615,000. l Routine: 1) Restarting from the steady solution with fixed trim and sinkage of EFD of 5512 ship for saving computational time, 2) Artificial damp is used and coefficient=0.1.
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Case3:
ONR
Tumblehome Model DTMB 5613
Computation conditions l Steady single water free surface flow, Reynolds number= 6.5E+6, Froude number=0.4. l Five overset grids: ship hull, superstructure, bilge keel, skeg, and background grids. l Overset grid solver produces static overset grid files and transfer to CFD.
Top view Bottom view
Vortex and streamline |
Case4: Pitch and Heave
Computation conditions l 5512 ship (1:46.6 of DTMB 5415 ), Fr=0.41,Re=7.1E+6. l Incoming linear regular wave, wave length:1.5, wave slop: ak=0.025. l Radius of gyration rg_2 =0.25, weight coefficient = 0.237, static area= 0.074, gravity center (0.5059,0, 0.00984). l Pitch and heave motions are predicted, others are captive. l Half ship grids are used due to symmetry to longitudinal section. l Pitch and heave motions are predicted, others are captive. l Test the computation in extremely coarse overset grids (close to limit condition) or coarse grids: Four coarse overset grids (only background grid is fixed, others follow ship motions). l Verification and validation using three levels of coarse grids: 0.15, 0.25,0.40 million grids. Movie 1 (Fr=0.41) Movie 2 (Fr=0.28)
Fr=0.41 Fr=0.28
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Case5: Zigzag Manuvering
Case6: Course Keeping
Computation conditions
Vortex movie (bottom) Vortex movie (side)
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Case7: Multi-body, multi-appendage, and dynamics overset grids