WaveBench

Laboratory-grade 1D engine gas-dynamics, acoustics and forced-induction design suite.

• Platform: .NET 10 (LTS), Windows-native (WinUI 3 / Windows App SDK)
• Licence: Apache-2.0
• Audience: Formula SAE teams, race engine developers, professional engine designers, DIY engine enthusiasts
• Scope: intake and exhaust wave tuning · camshaft timing · collector configuration and cylinder pairing · exhaust sound design and auralisation · turbocharging and supercharging · multi-objective optimisation

No telemetry. No network calls at runtime. Your designs, dyno data and audio never leave your machine.

Status

Phases 0–10 complete. The complete build specification lives in docs/WaveBench-Master-Plan.md — a staged build contract with 26 phases, each with a hard acceptance gate. Physics before pixels: Phases 0–15 produce a headless, test-covered, validated engine; no UI exists before Phase 16.

What works today: species-resolved 1D gas dynamics (MUSCL-Hancock + HLLC, verified against exact Riemann solutions), well-balanced variable area, friction/heat/wall-thermal sources, reservoir/orifice/plenum/junction components, an FSAE restrictor that chokes at theory, motored and fired single/multi-cylinder engines with wave-tuned VE curves, Wiebe combustion with knock tracking, a transfer-matrix acoustics engine cross-validated against the nonlinear solver to 0.45 dB, collector pulse-timing analysis that reproduces the crossplane-vs-flat-plane signature from firing order alone, audio synthesis (phase-coherent crank-angle wavetables, BS.1770 level-matched A/B, WAV export with provenance), and a CLI that runs models, sweeps, mesh studies, renders audio and executes the validation suite.

Headless CLI

wavebench info   examples/single-360.json
wavebench run    examples/single-360.json --rpm 5000
wavebench sweep  examples/single-360.json --from 4000 --to 9000 --step 500 \
                 --db results.db --plot sweep.png
wavebench mesh   examples/single-360.json --rpm 7000
wavebench render examples/single-360.json --from 2500 --to 7500 --seconds 9
wavebench validate --out validation

render solves an rpm grid, builds crank-angle wavetables from the solved pressure history and synthesises phase-coherent audio — 24-bit/48 kHz WAV with separate exhaust/intake stems and a provenance sidecar recording the model hash, seed and resolved bandwidth. Content above that bandwidth is labelled as not physically resolved rather than presented as prediction.

Validation

Every claim is backed by a committed comparison (see validation/ and docs/physics.md). First published-data case: the open-access CSU thesis runner-length study — WaveBench reproduces the published optimum exactly at 800 mm and within the 250 rpm gate at 600 mm:

Have dyno data with known geometry (especially FSAE)? Please open an issue — a measured case with provenance is the most valuable contribution this project can receive.

Building

dotnet build
dotnet test

Requires the .NET 10 SDK. The desktop app project is a placeholder until Phase 16; everything else is cross-buildable class libraries plus a CLI.

Solution layout

Project	Purpose
WaveBench.Core	Physics: thermodynamics, 1D solver, components, engine model (no UI, no I/O beyond streams)
WaveBench.Acoustics	TMM, radiation, order analysis, psychoacoustics, synthesis
WaveBench.Boost	Turbo/supercharger maps, shaft dynamics, thermal states, boost control
WaveBench.Model	Serialisable model tree, strongly-typed units, validation rules, provenance
WaveBench.Analysis	Post-processing, FFT, wave decomposition
WaveBench.Optimize	DOE, optimisers, surrogates, constraints
WaveBench.Cli	Headless runner and scripting entry point
WaveBench.App	WinUI 3 desktop app (Phase 16+)

Tests: WaveBench.Core.Tests (unit), WaveBench.Verification (§6.1, per-PR CI), WaveBench.Validation (§6.2, nightly), WaveBench.Bench (BenchmarkDotNet).

Ground rules (from the plan, Part 0)

1. Do not skip phases; every gate must pass before proceeding.
2. TDD is mandatory in the physics layers, tested against analytical or published references.
3. Every empirical correlation is cited in an XML doc comment with its validity range.
4. WaveBench.Core never references a UI assembly (enforced by an architecture test).
5. Determinism: same input file → bit-identical results.
6. Docs ship in the same commit as the code.