Creaform was asked by a major client in the recreational vehicle industry to assess the water impact loads of a boat in a variety of impact scenarios (load cases). Water impact loads are critical for high speed vessels, such as speedboats.
The project was achieved using a one-way coupling approach between a CFD and a FEA analysis. First, the complex physics of water impact was simulated in CFD using a transient simulation in order to obtain the acceleration history of the boat and pressure mappings at each time step on the hull.
Second, the critical mappings were exported and used in the FEA structural analysis to assess strength. Inertia relief simulations were then performed to evaluate the stress induced on hull for these critical time steps.
Creaform’s engineering team was able to assess the strength and survivability of the hull. The numerical analysis results were used for thickening critical components and the addition of ribs and mounting points.
- Selection of water impact scenarios
- Preliminary analysis of geometry and simulation strategy
- Geometry preparation using surface wrapper
- Volumetric meshing using the trimmer mesher
- Boundary conditions specification for wave generation
- Setting of physical models and numerical parameters
- Simulations monitoring
- Post-processing and data mapping
- Finite element modeling
- Pre-processing of CFD results and translation to usable loads
- Application of pressure mappings within inertia relief analyses
- Post-processing of stress induced by pressure mappings
- Identification of critical areas to be modified
TOOLS AND METHODS USED
Based on the client’s needs, Creaform used the following tools and methods:
- Overset mesh/Dynamic Fluid Body Interaction/Volume of Fluid (VOF)/Wave Model/ URANS
- Femap/NEi Nastran