/simulation-bridge

name: simulation-bridge
version: 1.0.0
description: Generates simulation inputs across fidelity levels — OpenFOAM CFD cases, ngspice netlists, interactive React artifacts, and FreeCAD FEM setups — from verified engineering calculations.
domain: physical-infrastructure
tier: analysis
depends_on:
  - fluid-systems
  - power-systems
  - thermal-engineering
safety: no-autonomous-execution

Simulation Bridge Skill

> **Note**: This skill generates simulation INPUT files. The skill does not execute simulations. Users run the generated files in their local OpenFOAM, ngspice, or FreeCAD installations. All simulation results must be interpreted by qualified engineers before use in design decisions.

Summary (always loaded — ~2K tokens)

The simulation bridge translates verified engineering calculations into simulation-ready inputs across three fidelity levels:

| Level | Tools | Purpose | Time to Run | |-------|-------|---------|-------------| | 1 — Game-based | Minecraft Redstone, Factorio, React artifacts | Intuition building, parameter exploration | Seconds (interactive) | | 2 — Simplified | Hardy-Cross (pipes), Nodal (circuits), thermal balance | Engineering estimation | Minutes (in-browser) | | 3 — Professional | OpenFOAM, ngspice, FreeCAD FEM | Rigorous verification | Hours (local install required) |

**When to use this skill:**

• Calculations are complete and verified by domain skills
• User wants to visualize behavior before committing to construction
• User needs professional simulation evidence for code compliance or peer review
• User is learning — wants to build intuition from game mechanics up to CFD

**Output format:** All outputs are `SimulationPackage` objects:

import { SimulationPackage } from '../../types/infrastructure';

type SimulationPackage = {
  type: 'openfoam' | 'ngspice' | 'freecad-fem' | 'react-artifact';
  description: string;
  files: Record<string, string>;  // filename → file content
  runInstructions: string;
};

**Quick start:**

User: "Generate an OpenFOAM case for the data center cooling system"
→ This skill | type: openfoam | template: data-center-airflow | Depends on: fluid-systems calculations

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Active Tier (loaded when simulation tasks are active — ~10K tokens)

Simulation Hierarchy

Level 1: GAME-BASED (Intuition)
├── Minecraft Redstone → Logic circuits, signal propagation, spatial reasoning
├── Factorio          → Fluid networks, throughput optimization, logistics
└── React artifacts   → Interactive parameter exploration (this skill generates these)

Level 2: SIMPLIFIED ANALYSIS (Engineering Estimation)
├── Pipe network solver (Hardy-Cross method) — embedded in React artifact
├── DC circuit solver (nodal analysis)       — embedded in React artifact
└── Steady-state thermal balance             — embedded in React artifact

Level 3: PROFESSIONAL SIMULATION (Verification)
├── OpenFOAM    → CFD for airflow, liquid cooling, heat transfer
├── ngspice     → Circuit simulation for power distribution
└── FreeCAD FEM → Structural loads, thermal conduction

Progressive fidelity path: 1. Start with game analogy (understand the concept) 2. Build interactive React artifact (explore parameters) 3. Generate OpenFOAM/ngspice input (validate with professional tool) 4. Run solver locally (obtain rigorous results) 5. Return results to design (close the verification loop)

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OpenFOAM Case Generation (SIM-01, SIM-06)

OpenFOAM uses a structured case directory with required files. This skill generates all required files.

**Case directory structure:**

case-name/
  system/
    controlDict        <- Solver settings, time step, write frequency
    fvSchemes          <- Numerical discretization schemes
    fvSolution         <- Linear solver settings and convergence criteria
    blockMeshDict      <- Structured mesh definition
    snappyHexMeshDict  <- (Optional) Unstructured mesh from STL geometry
  constant/
    physicalProperties <- Fluid properties (density, viscosity, thermal conductivity)
    turbulenceProperties <- Turbulence model selection (k-e, k-w SST, etc.)
  0/
    U                  <- Initial velocity field (m/s)
    p                  <- Initial pressure field (Pa or relative)
    T                  <- Initial temperature field (K) — thermal cases only
    k                  <- Turbulent kinetic energy (k-e/k-w models)
    epsilon            <- Turbulent dissipation (k-e model)
    omega              <- Specific dissipation (k-w model)

**Three pre-configured templates** (full content in references/openfoam-templates/):

**Template 1: data-center-airflow**

• Solver: `buoyantSimpleFoam` (buoyancy-driven steady-state)
• Turbulence: k-e standard
• Geometry: Raised-floor plenum with perforated tiles, rack heat sources, CRAC units
• Parametric inputs: room dimensions, rack heat loads, CRAC supply temperature and flow rate, tile open area
• Key output: Temperature distribution, velocity vectors, hot spot identification

**Template 2: pipe-flow-pressure-drop**

• Solver: `simpleFoam` (incompressible steady-state)
• Turbulence: k-w SST (preferred for pipe flow with fittings)
• Geometry: Pipe with fittings (elbow, tee, valve)
• Parametric inputs: pipe diameter, flow velocity, fluid viscosity
• Key output: Pressure drop validation against Darcy-Weisbach calculation

**Template 3: heat-exchanger-performance**

• Solver: `chtMultiRegionFoam` (conjugate heat transfer)
• Turbulence: k-w SST
• Geometry: Counter-flow or parallel-flow geometry
• Parametric inputs: inlet temperatures and flow rates for both fluids
• Key output: Heat transfer coefficient, LMTD comparison to analytical result

**Generating a case from design data:**

Inputs from fluid-systems skill:
  pipe_diameter: 100mm, flow_rate: 3.5 L/s, fluid: water at 15C

Generated controlDict (excerpt):
  application     simpleFoam;
  startTime       0;
  endTime         500;
  deltaT          1;
  writeInterval   50;

Generated 0/U boundary conditions: