```html Seastead Simulation Software Comparison

Open Source Software for Seastead Simulation in Waves

Based on your detailed description of an unconventional trimaran-like seastead with large, partially submerged NACA foil-shaped legs, here's a comprehensive comparison of open-source simulation tools that can handle wave interactions with complex geometries.

Key Challenge: Your design's large, partially submerged foils (19ft legs, 50% submerged) will experience significant non-linear effects as they interact with waves, especially at higher wave amplitudes. Standard Boundary Element Method (BEM) approaches may struggle with the large motions and changing wetted surfaces.

Software Comparison Overview

Software Method GPU Support Accuracy for Your Design Setup Time (with Claude Code) Visualization Python Integration
DualSPHysics Smoothed Particle Hydrodynamics (SPH) ✅ Excellent (CUDA/OpenCL) ★★★★★ 2-4 weeks ✅ Good built-in ⚠️ Limited (post-processing)
OpenFOAM Computational Fluid Dynamics (CFD) ⚠️ Via external libraries ★★★★★ 4-8 weeks ✅ Excellent (ParaView) ⚠️ Via wrappers
Capytaine + MoorDyn BEM + Mooring Dynamics ❌ No ★★★☆☆ (linear limitations) 1-2 weeks ⚠️ Requires custom work ✅ Native Python
Project Chrono (FSI-SPH) Multi-physics with SPH ✅ Yes ★★★★☆ 3-5 weeks ✅ Good (Irrlicht/VTK) ⚠️ C++/Python bindings
Blender (Mantaflow/Physics) Visual physics simulation ✅ Yes (via Cycles/EEVEE) ★☆☆☆☆ 1-2 weeks ★★★★★ ⚠️ Python scripting
WEC-Sim + MoorDyn BEM + Multi-body dynamics ❌ No ★★★☆☆ (linear limitations) 2-3 weeks ✅ Good (MATLAB) ❌ MATLAB required

Detailed Analysis of Each Option

1. DualSPHysics (SPH Method)

Pros:
Cons:

Setup Time: 2-4 weeks with Claude Code assistance. The main challenges will be creating the complex geometry of your seastead and setting up appropriate boundary conditions.

Best for: High-fidelity simulation of your unconventional design, especially for investigating non-linear effects and large amplitude motions.

2. OpenFOAM (CFD)

Pros:
Cons:

Setup Time: 4-8 weeks with Claude Code. Mesh generation for your complex geometry will be the most time-consuming part.

Best for: Ultimate accuracy if you have the patience and computational resources. Consider if you need publication-quality results.

3. Capytaine + MoorDyn (BEM + Mooring)

Pros:
Cons:

Setup Time: 1-2 weeks with Claude Code. Fastest path to initial results.

Best for: Quick parametric studies and initial design screening. Use results with caution for extreme conditions.

4. Project Chrono (FSI-SPH Module)

Pros:
Cons:

Setup Time: 3-5 weeks with Claude Code. Good balance between accuracy and development time.

5. Blender with Physics Add-ons

Important: Blender's native physics simulations (including Mantaflow) are designed for visual effects, not engineering accuracy. While you could potentially create visually compelling animations, the results would not be reliable for engineering decisions about stability or failure points.

Setup Time: 1-2 weeks, but only for visualization purposes, not accurate simulation.

Recommendation: Use Blender only for final visualization of results from a proper physics simulator, not as the simulation engine itself.

6. WEC-Sim + MoorDyn

While you correctly identified the MATLAB/Simulink cost issues, it's worth noting that WEC-Sim would likely struggle with your design due to the same BEM limitations as Capytaine. The commercial software requirements make it unsuitable for your "open source" criteria.

Recommended Approach for Your Specific Needs

Phase 1: Initial Screening (1-2 weeks)

Start with Capytaine + MoorDyn for quick parametric studies. Use it to:

This will help you quickly iterate through design variations.

Phase 2: High-Fidelity Validation (3-5 weeks)

For critical design validation and extreme wave conditions, use DualSPHysics. This will:

Phase 3: Visualization & Reporting

Use ParaView (for DualSPHysics/OpenFOAM) or custom Python scripts to create compelling visualizations that show how your design behaves in different sea states.

Answering Your Specific Questions

About Project Chrono::FSI-SPH vs BEM:

You are correct that Chrono::FSI-SPH uses Smoothed Particle Hydrodynamics, not BEM. This makes it suitable for your non-linear requirements. However, for pure hydrodynamic simulation of your specific design, DualSPHysics is likely a better specialized tool.

About Python Integration:

Capytaine + MoorDyn offers the best Python integration, making design iteration extremely fast. You could create parametric scripts that automatically test different leg positions, sizes, and wave conditions.

About Design Iteration Ease:

Once you have a simulation working for one design:

About Operating System:

All recommended tools work well on Linux. DualSPHysics and OpenFOAM actually perform best on Linux. You can develop on Windows if preferred, but consider Linux for production runs.

Estimated Total Timeline

With Claude Code assistance:

Conclusion

For your unconventional seastead design with large, partially submerged foils, I recommend a two-pronged approach:

  1. Capytaine + MoorDyn for rapid design iteration and parametric studies
  2. DualSPHysics for final validation and extreme condition analysis

This combination gives you both speed of iteration and engineering accuracy where it matters most. Your GPU will be particularly valuable for the SPH simulations, allowing you to run multiple wave conditions relatively quickly.

The key advantage of this approach is that you can quickly eliminate poor designs using the faster BEM method, then focus computational resources on validating the most promising candidates with high-fidelity SPH.

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