OpenWAM - BMW S54 CSL Simulator Fork

A fork of CMT-UPV/OpenWAM customized for high-fidelity BMW S54 (M3 CSL) engine simulation with Volumetric Efficiency (VE) table generation.

Key Modifications

OpenWAM Engine Core (C++)

• NaN Guards: Symmetric fallback to air properties (γ=1.386, R=287) in cylinder and pipe solvers
• Stability Fixes: Crash prevention for Pipe ID bounds and species transport
• Memory Modernization: std::unique_ptr, std::shared_ptr, std::string
• Parallelization: OpenMP enabled for flow calculations

CSL Simulator (Python)

A complete VE simulation pipeline for the S54B32HP engine:

• WAM Generator: Dynamic topology creation with 81 pipes, dual-bank exhaust, H-pipe crossover
• VANOS Integration: OEM map-based intake/exhaust cam timing
• VE Validation: 13-point sweep comparing simulation vs OEM ECU maps
• Parallel Execution: Multi-threaded VE table generation

Project Structure

OpenWAM/
├── Source/                              # C++ Engine Core
│   ├── Engine/TCilindro4T.cpp          # Cylinder solver (w/ NaN guard)
│   ├── 1DPipes/TTubo.cpp               # Pipe solver (w/ NaN guard)
│   └── CMakeLists.txt
├── build/                               # CMake build output
│   └── bin/release/OpenWAM.exe
├── CSL_Simulator/
│   ├── backend/
│   │   ├── app/
│   │   │   ├── models.py               # Pydantic config (S54 spec)
│   │   │   ├── data/csl_ecu_maps.json  # OEM VE/VANOS maps
│   │   │   └── simulator/
│   │   │       └── wam_generator.py    # WAM file generator
│   │   ├── scripts/                    # CLI tools
│   │   │   ├── ve_validation_sequential.py
│   │   │   └── ve_table_runner_parallel.py
│   │   └── output/                     # Generated files
│   └── docs/
│       └── csl_simulator_technical_spec.md
└── README.md

Build Instructions

OpenWAM Engine (C++)

Requirements: CMake 3.10+, C++17 compiler, OpenMP (optional)

mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
cmake --build . --config Release

CSL Simulator (Python)

Requirements: Python 3.10+, pandas

cd CSL_Simulator/backend
python scripts/ve_validation_sequential.py

S54 Engine Configuration

Parameter	Value
Bore × Stroke	87.0 × 91.0 mm
Displacement	3246 cc
Compression Ratio	11.5:1
Cylinders	6 (Inline)
Valve Lift	11.8 / 11.2 mm (In/Ex)

Validation Results

RPM Range	TPS Range	Accuracy
1400-3100	10-50%	±13%
3500-7000	65-100%	-23% to -35%

Status: 12/13 points passing (92%)

License

GNU General Public License v3.0 - See original OpenWAM for details.

Acknowledgments

• CMT-UPV/OpenWAM - Original engine simulation framework