A native desktop workstation for compressible-flow and liquid-rocket propulsion analysis. It covers classic gas dynamics, converging–diverging nozzle operation, NASA CEA chamber thermochemistry, ideal rocket performance and design-space trade studies in one Qt Quick interface. Every number on screen comes from a verified physics layer, and the views only ever read solved state.
Rocket Performance for LOX/LCH₄ at 100 bar, expanded to Aₑ/Aₜ 40 in vacuum: Isp 348.658 s from a NASA CEA chamber and the ideal rocket model. The 3D view is built from the solved area ratio and says so: schematic geometry, area expansion only, not a solved contour.
- Compressible flow. Isentropic flow, mass flow, normal and oblique shocks, Prandtl–Meyer, Fanno and Rayleigh flow. Each module opens on its relation, with a calculator and a generated table beside it.
- Nozzle Lab. Back-pressure regimes of a converging–diverging nozzle, from unchoked through internal normal shock to over- and underexpanded. It shows the solved station distribution across the shock and the shock station against back pressure.
- Thermochemistry. HP chamber equilibrium from NASA CEA 3.3.4, for bipropellant and solid formulations. Mixture-ratio sweeps show temperature, molar mass, isentropic exponent and species.
- Rocket Performance. The ideal rocket model from a solved chamber: c*, Cf with its signed pressure term, c_eff and Isp. It is drawn from the solved area ratio in 2D or 3D.
- Trade Study. Design variables, hard constraints and objectives, evaluated over a sampled grid. Pareto membership is decided on every objective, not only the two plotted. It evaluates a sample and is not an optimiser.
- Fluids and Feed. Fluid properties from CoolProp, and pressure drop in a straight line with the Darcy friction factor stated as such.
- Liquid Engine. The design chain starts from a requirement (thrust, design environment, burn time). It goes through a propellant trade, thrust-chamber and nozzle sizing, and chamber geometry, to injector orifice hydraulics with a pressure ledger for each branch. The model is ideal: no cooling, pump or cycle.
- Propulsion System. The stage around the engine, built on the liquid
engine chain. Nothing is defaulted, and an unknown term stays unresolved
rather than becoming zero.
- Propellant inventory: usable, residual, reserved and loaded propellant per branch.
- Tank sizing and packaging: liquid, ullage and tank volume, and the internal geometry of a sphere or a cylinder with hemispherical or ellipsoidal domes. No wall or structural sizing.
- Propellant management: how each outlet is kept covered, as a stated and checked declaration. Full slosh dynamics are not modelled.
- Tank pressurization: regulated stored gas and blowdown, with a perfect gas. Autogenous and warm-gas pressurization are future work.
- Feed network: pressure losses from tank outlet to injector inlet, closed against the injector ledger without counting a loss twice. No cavitation, transients, pumps, turbopumps or engine cycles.
- Engine Design. A topology editor for engine component networks with typed ports and structural checks. No physics is wired into it yet (see Known limitations).
 Nozzle Lab. An internal normal shock at A/Aₜ = 1.51009 for p_b/p₀ = 0.70, beside the shock station against back pressure. The shock is a quasi-1D station, not a resolved shock, and the flow cues show direction only. |
 Thermochemistry sweep, hover peek. A 41-point NASA CEA sweep. Hovering a plot enlarges it in place with its live readout, and one click opens it full size. |
 Isentropic Flow. Every classic module opens on its relation. The solved state at M = 2 is marked on the generated curve, and the calculator and the reference-checked table are one tab away. |
 Trade Study. 328 evaluated designs over O/F and Aₑ/Aₜ. For this capture, a second real objective, minimising chamber temperature, was added to the default maximise-Isp study, which gives a Pareto front. Every marker is an evaluated design, and the front is a sample of the grid. |
The views work on results that already exist; they never re-solve. A plot, its table and the Inspector share one selection per workspace, so picking a point, a row or a station shows the same solved sample everywhere. The tools are:
- plots that zoom, pan, probe and lens;
- a hover peek that enlarges a small multiple in place, with Focus one click further;
- table lenses and range selection;
- pinned table snapshots that compare two blocks side by side;
- 2D/3D engineering views that take their stations from the solved state.
Motion has Full, Reduced and Off settings, and the hover preview can be turned off.
A table lens across the shock in Nozzle Lab's station distribution. The pre-shock and post-shock states share one axial position and stay two rows, because the jump between them is the result.
- Layered, frozen physics. The layers are
core → physics → engineering → engine → providers → application. Qt lives only inapplication, and NASA CEA and CoolProp only inproviders.tests/test_architecture.pyenforces those boundaries. - Verified thermochemistry. NASA CEA is the runtime provider. Cantera is a development-only independent oracle, and both are checked against published references (CEA / Cantera verification).
- Reference checks in the product. The isentropic, normal-shock and Prandtl–Meyer calculators compare their solved state with Anderson's published tables (Appendices A–C). When a state has no exact tabulated row, they say so instead of interpolating one.
- Zero-view-solve. Selecting, zooming, lensing, peeking, playing back cached shock samples and switching 2D/3D issue no solver calls. This is audited with instrumented solver entry points and live positive controls.
- Source/package parity.
--selftest-sciencewrites a bit-exact digest of every published value. A packaged build must match its source commit float for float. - Honest drawings. Schematics are labelled for what they are. RocketForge's solvers are 0-D/1-D, so it draws no CFD, no flame and no fabricated contour.
| Area | Status |
|---|---|
| Classic gas dynamics (Fanno, Rayleigh, isentropic, normal/oblique shock, Prandtl–Meyer, mass flow) | Frozen, rocketforge.physics.compressible |
| Thermochemistry (NASA CEA primary provider, Cantera dev-only independent oracle) | Verified. CEA and Cantera are both confirmed against external published references, and cross-provider consistency holds within an evidenced envelope. See docs/engineering/verification/CEA_CANTERA_VERIFICATION_R1.md |
| Fluid properties | Frozen, rocketforge.physics.fluids |
| Line / transport (pressure drop, friction) | Frozen v1.0, rocketforge.engineering.line |
| Chamber + nozzle performance (c*, Cf, Isp) | Frozen v1.0. Scalar only: no geometry, contour or dimensions |
- Engine Design mode is presentation-only. Its topology editing is real, but none of its 16 component types is solved. Nothing is propagated along a connection, and every quantitative readout is an em-dash placeholder.
- Performance is the ideal-rocket model, with no efficiency factors and no nozzle contour design.
- No unit conversion. The unit indicator is fixed to SI.
- Charts, Compare and Gas Properties are planned modules that are not built yet.
- Verified on Windows 11, where the 3D view needs Qt Quick 3D and a 3D-capable renderer. Without them the 2D view stays and says why.
The full list is in docs/REFERENCE.md.
The light theme is a complete palette of its own, not a filter over the dark one.
Windows build. Download it from
Releases. It is
self-contained and needs no Python. A release is a tagged version, and
master may be ahead of it. Every package names the commit it was built from:
see Settings → Copy build info.
From source (Python 3.13, PySide6 6.10.2):
python -m venv .venv
.venv\Scripts\activate
pip install -r requirements.txt
python main.pyrequirements.txt covers the shell and the compressible-flow modules. Three
optional, additive profiles unlock the rest:
requirements-thermochemistry.txtinstalls NASA CEA, for Thermochemistry, Rocket Performance and Trade Study. Cantera is deliberately not a runtime dependency.requirements-fluids.txtinstalls CoolProp, for Fluid Properties and Line.requirements-3d.txtinstalls PySide6-Addons, for the Qt Quick 3D views.
run.bat starts the source tree with the project environment, and its window
title says [DEV <commit>].
conda / miniforge users: use a plain virtual environment. A conda
icuon the DLL search path breaksimport PySide6.QtCore.
.venv\Scripts\python.exe -m pytest -q
.venv-cea\Scripts\python.exe -m pytest -qThe first command runs the base suite. The second adds the NASA CEA provider
tests, from an environment with the thermochemistry and fluids profiles. Call
the venv's own interpreter, never a bare python or pytest: on machines with
conda installed, the bare command can resolve to the wrong interpreter.
CI runs three jobs on every push:
- the base suite;
- the production profile (NASA CEA + CoolProp);
- the base suite at the declared minimum versions.
Tests that read developer-machine evidence (the untracked acceptance/
folder) skip themselves, with the reason, when it is absent.
build_exe.batThis is the one build command, and dist\RocketForge\RocketForge.exe is the
one package.
- Preconditions: it refuses a dirty or unpushed tree and any unpinned PySide6, NASA CEA, CoolProp or PySide6-Addons.
- Identity: it stamps the commit into the package.
- Verification: it verifies the result by running the package itself.
Build identity, launch paths and verification are covered in docs/engineering/release/BUILD_AND_LAUNCH.md.
- docs/README.md: the index of specs, implementation phases and verification campaigns.
- docs/REFERENCE.md: keyboard shortcuts, project structure, the Engine Design architecture, the design system, the component inventory and the full limitations list.
- docs/engineering/INTERACTIVE_VISUALIZATION_CONTRACT.md: what the interactive views may and may not do.
- CONTRIBUTING.md and CHANGELOG.md.
MIT.