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An authority-controlled, first-principles liquid rocket preliminary propulsion analytical toolkit with primary literature provenance.
🚀 Live Interactive App • What Is Launched • Step-by-Step Guide • 4 Canonical Injectors • Day 3: Cooling Channels • Day 4: Supersonic Nozzle • Day 5: Turbomachinery & Cycles • Day 6: Flight Engine Benchmarks • Day 6: Throttling & Chugging • Architecture
🚀 Live Interactive Web Application: navronis.github.io/Navronis-Propulsion
Run combustor, injector, regenerative cooling, supersonic bell nozzle, turbopump cycle power balance, flight ascent trajectory, real-engine presets, and off-design throttling directly in your browser with real-time SVG CAD geometry and zero installation.
Most preliminary rocket propulsion scripts in circulation rely on undocumented constants, uncalibrated combustion efficiencies, or misattributed empirical formulas.
Navronis is built on a strict mathematical foundation:
- Zero Silent Defaults: Inputs and intermediate results are strictly validated. Non-physical states fail explicitly rather than silently propagating errors.
- Traceable Engineering Provenance: Every computed parameter carries its governing equation, validity domain, and exact literature citation (NASA SP-125, NASA SP-194, NASA SP-8087, NASA SP-8107, NASA SP-8110, Bartz 1957, Gnielinski 1976, Haaland 1983, Rao 1958, Stark 2005, Huzel & Huang 1992, Sutton & Biblarz 2016, Rachov et al. 2010).
- Self-Explaining Engine: The calculation engine explains every derived value upon request via
.explain("parameter_name"). - Zero Heavy CAD/CFD Dependencies: Pure Python, NumPy, and SciPy core. Runs instantaneously on Linux, macOS, and Windows.
| Component | Status | Governing Physics & Scope | Primary References |
|---|---|---|---|
| Day 1: Combustor Assembly | 🟢 Released (v0.1.0)
|
Choked sonic throat continuity, Humble contraction ratio, barrel length, stay time, Bartz throat convective heat flux, NASA SP-194 acoustic cavity buzz modes (1T, 1R, 1L), ASME Section VIII hoop wall thickness. | NASA SP-125, Bartz (1957), NASA SP-194, ASME Sec VIII |
| Day 2: 4 Canonical Injectors | 🟢 Released (v0.2.0)
|
Torricelli hydraulics, chugging feed-system acoustic decoupling ( |
NASA SP-194, Yang et al. (2004), Bazarov & Yang (1998), Dressler (2000), Rupe (1956) |
| Day 3: Regen Cooling Channels | 🟢 Released (v0.3.0)
|
Milled rectangular channel aspect ratio, Haaland friction factor, Gnielinski turbulent forced convection, fin efficiency enhancement ( |
NASA SP-8087, Gnielinski (1976), Haaland (1983), Bartz (1957), Incropera |
| Day 4: Supersonic Nozzle & Aero | 🟢 Released (v0.4.0)
|
1D isentropic Area-Mach inversion, Rao 80% parabolic bell contour quadratic Bézier, 1976 US Standard Atmosphere (0–85 km), Stark (2005) tri-criteria flow separation, divergence efficiency ( |
NASA SP-125, Rao (1958), Stark (2005), Summerfield (1954), NOAA/NASA 1976 |
| Day 5: Turbomachinery Cycles | 🟢 Released (v0.5.0)
|
Centrifugal pump hydraulic head ( |
Huzel-Huang (1992), Sutton-Biblarz (2016), NASA SP-8107, NASA SP-8110 |
| Day 5: 2D Powered Ascent Trajectory | 🟢 Released (v0.5.0)
|
2D point-mass gravity turn powered ascent, transonic wave drag curve |
Griffin & French (2004), NASA SP-8087, Sutton-Biblarz (2016) |
| Day 5: Master Engine Architecture | 🟢 Released (v0.5.0)
|
Unified end-to-end EngineSystem synthesizer coupling Combustor + Injectors + Regen Jacket + Rao Nozzle + Turbomachinery Balance + Flight Trajectory into complete aerospace engine datasheets with JSON/CSV export. |
AIAA / NASA Industry Standard Engine Datasheet Spec |
| Day 6: Flight Engine Validation Decks | 🟢 Released (v0.6.0)
|
7 authoritative historical reference decks (Merlin 1D, Raptor 2, RS-25, RD-180, RL10, Rutherford, LMDE) verified against NASA/AIAA test-stand datasets (4.40% grand mean error across all engines). | NASA TN D-7143, NASA SP-8107, SpaceX Guides, Sutton & Biblarz (2016) |
| Day 6: Off-Design Throttling & Chugging | 🟢 Released (v0.6.0)
|
Dynamic off-design throttling sweep ( |
NASA SP-194, Summerfield (1954), Stark (2005) |
| Day 6: Electric Motor Turbopump | 🟢 Released (v0.6.0)
|
BLDC motor power density ( |
Rachov et al. (2010), Rocket Lab User's Guide |
| Live Browser Web Sizer | 🟢 Live | Interactive client-side UI hosted on GitHub Pages. Real-time SVG CAD cross-section rendering, flight engine presets dropdown, off-design throttle slider with live chugging status, and 127-test verification matrix. | Client-side pure HTML5/SVG/JS |
Rather than attempting to model dozens of obscure injector variations, Navronis strictly focuses on the 4 canonical injector families that power virtually all operational liquid rocket propulsion systems:
1. SHEAR COAXIAL 2. SWIRL COAXIAL 3. CENTRAL PINTLE 4. IMPINGING DOUBLET
(SSME, RL10, Raptor) (RD-170, RD-180, NK-33) (LMDE, Merlin 1D) (Apollo SPS, Titan II)
Gas Annulus Swirl Outer Gas Fuel Annular Sheet Fuel Oxidizer
┌───────────┐ ┌───────────────┐ ┌────────────────┐ \ /
│ ┌───┐ │ │ ┌───────┐ │ │ ┌────────┐ │ \ /
│ │Ox │ │ │ │ Vortex│ │ │ │ Radial │ │ \ /
│ │Liq│ │ │ │ Liquid│ │ │ │ Pintle │ │ ▼ ▼
│ └───┘ │ │ └───────┘ │ │ └────────┘ │ Collision Fan
└───────────┘ └───────────────┘ └────────────────┘ (Atomization)
-
Shear Coaxial Injectors (
coaxial): High-speed annular gas shears a central liquid core (e.g. SSME / RS-25, RL10, Vulcain, Raptor).-
Key physics: Momentum flux ratio
$J = \frac{\rho_g V_g^2}{\rho_l V_l^2}$ ($2 \le J \le 20$ ), Lorenzetto-Lefebvre (1977) droplet atomization ($D_{32}$ ), recess ratio$R_L$ .
-
Key physics: Momentum flux ratio
-
Centrifugal Swirl Coaxial Injectors (
swirl): Tangential inlet ports create a rotating liquid film with a hollow central gas core, enveloped in an annular gas stream (e.g. RD-170, RD-180, NK-33).-
Key physics: Abramovich centrifugal swirl discharge coefficient (
$C_d$ ) from geometric swirl characteristic ($K$ ), hollow gas core diameter, annular liquid film thickness, spray half-cone angle$\theta$ , and Lefebvre (1989) pressure-swirl droplet SMD ($D_{32}$ ).
-
Key physics: Abramovich centrifugal swirl discharge coefficient (
-
Central Pintle Injectors (
pintle): Continuous annular sheet deflected outward by an impinging central radial spray, providing wide throttling margins (e.g. Apollo LMDE, SpaceX Merlin 1D).-
Key physics: Total Momentum Ratio $TMR = \frac{\dot{m}{rad} V{rad}}{\dot{m}{ann} V{ann}}$, resultant spray cone half-angle
$\beta = \arccos\left(\frac{1}{1 + TMR}\right)$ , acoustic decoupling stiffness.
-
Key physics: Total Momentum Ratio $TMR = \frac{\dot{m}{rad} V{rad}}{\dot{m}{ann} V{ann}}$, resultant spray cone half-angle
-
Unlike Impinging Doublet Injectors (
impinging): Discrete intersecting liquid jets forming an atomizing spray fan (e.g. Apollo SPS, Titan II, Viking).-
Key physics: Rupe (1956) dynamic head balance
$\frac{\rho_1 v_1^2 d_1}{\rho_2 v_2^2 d_2} = 1.0$ , free jet impingement length, Ingebo (1958) droplet atomization.
-
Key physics: Rupe (1956) dynamic head balance
Day 3 introduces high-pressure milled cooling jacket design. Fuel circulating through milled rectangular passages absorbs heat conducted through the chamber liner:
COOLANT MANIFOLD / CHANNELS (High Speed Coolant vc ~ 50 m/s)
┌──────────────────────────────────────────────────────────────────┐
│ CHANNEL │ RIB FIN │ CHANNEL │ RIB FIN │ CHANNEL │
│ (w_c x h_c) │ (t_fin) │ (w_c x h_c) │ (t_fin) │ │
└───────▲────────────▲──────────────▲────────────▲─────────────▲───┘
│ │ │ │ │ qc = hc,eff (Twc - Tbulk)
══════════════╪════════════╪══════════════╪════════════╪═════════════╪═══════ Coolant Wall (Twc)
│ │ RADIAL FOURIER CONDUCTION: q = (Twg - Twc) / (tw / kw)
══════════════╪════════════╪══════════════╪════════════╪═════════════╪═══════ Hot-Gas Wall (Twg)
│ │ │ │ │ qg = hg (Taw - Twg)
HOT COMBUSTION GAS & NOZZLE ACCELERATION (Flame Temp Tc ~ 3,400 K)
-
Perimeter Packing:
$w_c = \frac{\pi D_t - N \cdot t_{fin}}{N}$ , Aspect Ratio$AR = \frac{h_c}{w_c}$ ,$D_h = \frac{2 w_c h_c}{w_c + h_c}$ -
Coolant Convection:
$Nu = \frac{(f/8)(Re - 1000)Pr}{1 + 12.7\sqrt{f/8}(Pr^{2/3} - 1)}$ (Gnielinski 1976 / Filonenko) -
Rough Channel Friction:
$\frac{1}{\sqrt{f}} = -1.8 \log_{10}\left[\left(\frac{\epsilon/D_h}{3.7}\right)^{1.11} + \frac{6.9}{Re}\right]$ (Haaland 1983) -
Fin Efficiency:
$\eta_{fin} = \frac{\tanh(m h_c)}{m h_c}$ , where$m = \sqrt{\frac{2 h_c}{k_w t_{fin}}}$ -
Conjugate Wall Closure:
$q = \frac{T_{aw} - T_{bulk}}{\frac{1}{h_g} + \frac{t_w}{k_w} + \frac{1}{h_{c,eff}}}$ ,$T_{wg} = T_{aw} - \frac{q}{h_g}$ ,$T_{wc} = T_{bulk} + \frac{q}{h_{c,eff}}$ -
Coolant Pressure Drop:
$\Delta P = f \left(\frac{L_{channel}}{D_h}\right) \left(\frac{\rho_c v_c^2}{2}\right)$ -
Thermal Stress:
$\sigma_{th} = \frac{E \alpha (T_{wg} - T_{wc})}{2(1 - \nu)}$ , Yield Margin$MS = \frac{S_y}{\sigma_{th}} - 1.0$
Day 4 couples supersonic nozzle expansion to the 1976 US Standard Atmosphere:
-
Rao 80% Parabolic Bell Contour: Sized using quadratic Bézier formulation from entrance angle
$\theta_n \approx 30^\circ$ to exit lip angle$\theta_e \approx 8^\circ$ , delivering$\sim 98.3%$ divergence efficiency with$\sim 20%$ shorter length than a$15^\circ$ conical bell. -
1D Supersonic Area-Mach Inversion: Solves the isentropic Area-Mach relation across expansion ratios
$\varepsilon \in [2, 300]$ using Newton-Raphson and bracketed bisection. -
1976 US Standard Atmosphere Model: Barometric formula with continuous temperature lapse rates across Troposphere, Tropopause, and Stratosphere (
$0$ to$85\text{ km}$ ). -
Flow Separation & Side-Load Prevention: Stark (2005) tri-criteria evaluation combining Summerfield (
$P_{sep} \approx 0.375 P_a$ ), Schmucker Mach-scaled limit ($P_{sep} = 0.64 M^{-1.88} P_a$ ), and Kalt-Badal pressure criteria.
Day 5 introduces complete liquid rocket turbomachinery sizing and closed-loop engine cycle power balancing:
PRESSURE-FED GAS GENERATOR EXPANDER (CLOSED)
┌──────────────────┐ ┌──────────────────┐ ┌──────────────────┐
│ Regulated Helium │ │ Fuel + Ox Bleed │ │ Regen Jacket │
│ High-P Tanks │ │ Gas Generator │ │ Vapor Heat Drive │
└─────────┬────────┘ └─────────┬────────┘ └─────────┬────────┘
│ │ (Dump Loss) │ (No Dump Loss)
▼ ▼ ▼
Combustor Turbine ──► Pumps Turbine ──► Pumps
│ │
▼ ▼
Combustor Combustor
STAGED COMBUSTION (ORSC / FRSC) FULL-FLOW STAGED COMBUSTION (FFSC / RAPTOR)
┌────────────────────────────┐ ┌────────────────────────┐ ┌────────────────────────┐
│ Single High-P Preburner │ │ Ox-Rich Preburner │ │ Fuel-Rich Preburner │
│ (100% of Ox or Fuel Flow) │ │ Drives Ox Turbopump │ │ Drives Fuel Turbopump │
└─────────────┬──────────────┘ └───────────┬────────────┘ └───────────┬────────────┘
▼ │ │
Preburner Gas ▼ ▼
Turbine ──► Pumps Hot Gas Oxidizer Hot Gas Fuel
│ │ │
▼ └─────────────┬─────────────┘
Combustor ▼
Gas-Gas Main Combustor
-
Pump Hydraulic Head:
$H = \frac{P_{discharge} - P_{inlet}}{\rho g_0}$ [meters] -
Pump Shaft Power:
$\dot{W}_p = \frac{\dot{m} \Delta P}{\rho \eta_p} = \frac{\dot{m} g_0 H}{\eta_p}$ [Watts] -
Specific Speed:
$N_s = \frac{N \sqrt{Q}}{H^{3/4}}$ (Classifies Radial Centrifugal$N_s < 1500$ , Mixed$1500 \le N_s \le 4500$ , or Axial$N_s > 4500$ ) -
Cavitation Margin &
$N_{ss}$ :$N_{ss} = \frac{N \sqrt{Q}}{NPSH^{3/4}}$ with inducer cavitation threshold$NPSH_R = \left(\frac{N \sqrt{Q}}{N_{ss,limit}}\right)^{4/3}$ -
Turbine Isentropic Work:
$\Delta h_{iso} = c_p T_{in} \left[1 - \left(\frac{1}{PR}\right)^{\frac{\gamma-1}{\gamma}}\right]$ , Extraction Power $\dot{W}_t = \dot{m}t \eta_t \Delta h{iso}$ - Gas Generator Balance: $\dot{m}{gg} = \frac{\dot{W}{p,ox} + \dot{W}{p,fuel}}{\eta_t \Delta h{iso}}$, Net Cycle $\text{Isp}{vac} = \text{Isp}{main} (1 - \alpha_{gg}) + \text{Isp}{gg} \alpha{gg}$
- Expander Heat Pinch: Power margin $\chi_{exp} = \frac{\dot{m}{cool} c_p \Delta T{cool} \eta_t [1 - (1/PR)^{\frac{\gamma-1}{\gamma}}]}{\dot{W}{p,ox} + \dot{W}{p,fuel}} \ge 1.0$
Simulates point-mass powered flight from the launch pad through atmospheric pitch-over to orbital cutoff:
-
Gravity Turn Flight Dynamics:
$\frac{dv}{dt} = \frac{F - D}{m(t)} - g \sin\gamma$ ,$\frac{d\gamma}{dt} = -\left(\frac{g}{v} - \frac{v}{r}\right)\cos\gamma$ -
Transonic Wave Drag Curve:
$C_D(M)$ capturing subsonic drag ($C_D \approx 0.28$ ), transonic sonic-boom drag peak at Mach 1.05 ($C_D \approx 0.60$ ), and supersonic Prandtl-Glauert/von Kármán wave decay. -
Atmospheric Max Q: Dynamic pressure
$q(t) = \frac{1}{2} \rho(z) v^2$ , identifying peak aerodynamic structural load magnitude and altitude. -
Flight Loss Accounting: Numerical quadrature of gravity loss
$\Delta V_{grav} = \int g \sin\gamma , dt$ , aerodynamic drag loss$\Delta V_{drag} = \int \frac{D}{m} , dt$ , and orbital velocity deficit against a$200\text{ km}$ circular LEO target ($v_{circ} = \sqrt{\mu / r_{LEO}} \approx 7784\text{ m/s}$ ).
Couples all 5 subsystems into a single unified object:
Combustor (Day 1) + 4 Injectors (Day 2) + Regen Cooling (Day 3) + Rao Nozzle (Day 4) + Turbopump (Day 5) + Ascent (Day 5)
│
▼
Unified EngineSystem Datasheet
- Open https://navronis.github.io/Navronis-Propulsion/.
- Select engine cycle (Gas Generator, Expander, Staged Combustion, Full-Flow Staged, or Pressure-Fed).
- Tweak parameters across Combustor, Injectors, Regen Cooling, Nozzle, and Flight Mass.
- Inspect real-time 2D CAD assembly cross-section, turbopump shaft power gauges, and ascent flight trajectory telemetry.
git clone https://github.com/Navronis/Navronis-Propulsion.git
cd Navronis-Propulsion
python -m pip install -e .navronis --subsystem chamber --thrust 30000 --pc 70 --propellants LOX/CH4navronis --subsystem injector --injector-type coaxial --thrust 30000 --pc 70 --propellants LOX/CH4 --elements 19navronis --subsystem cooling --thrust 30000 --pc 70 --propellants LOX/CH4 --channels 80 --channel-height 1.8 --fin-thickness 0.8navronis --subsystem nozzle --thrust 30000 --pc 70 --propellants LOX/CH4 --expansion-ratio 30 --altitude 12000navronis --subsystem cycle --thrust 40000 --pc 70 --propellants LOX/CH4 --cycle gas_generatornavronis --subsystem trajectory --thrust 180000 --vehicle-mass 12000 --payload-mass 350 --burn-time 150navronis --subsystem system --thrust 50000 --pc 70 --propellants LOX/CH4 --cycle gas_generatorfrom kryptonis.propulsion_equations import (
CombustorDesign,
InjectorDesign,
RegenCoolingJacket,
NozzleDesign,
EngineCycleDesign,
TrajectorySimulation,
EngineSystem,
)
# Complete End-to-End Rocket Engine System
engine = EngineSystem(
name="Methalox-50kN",
thrust_sea_level=50000.0,
chamber_pressure=70.0e5,
propellant="LOX/CH4",
cycle_type="gas_generator",
expansion_ratio=35.0,
vehicle_liftoff_mass_kg=12000.0,
payload_mass_kg=350.0,
)
result = engine.solve()
# Print comprehensive aerospace engine datasheet
print(result.summary_report())
# Export full engineering JSON specification
json_spec = result.to_json(indent=2)Navronis includes authoritative reference specifications for 7 iconic flight rocket engines, validated against NASA SP reports, AIAA technical papers, and manufacturer flight manuals:
# Run verification benchmarks across all 7 flight engines
navronis --benchmark
# Or run a detailed analytical comparison on a single engine
navronis --engine merlin1d --benchmark| Engine | Organization | Propellant | Power Cycle | Ref. Thrust | Ref. Isp | Navronis Error | Status |
|---|---|---|---|---|---|---|---|
| SpaceX Merlin 1D | SpaceX | LOX / RP-1 | Gas Generator | 914 kN (Vac) | 311.0 s (Vac) | 4.39% mean error | 🟢 PASS |
| SpaceX Raptor 2 | SpaceX | LOX / CH4 | Full-Flow Staged | 2450 kN (Vac) | 350.0 s (Vac) | 8.84% mean error | 🟢 PASS |
| Aerojet RS-25 (SSME) | Aerojet / NASA | LOX / LH2 | Fuel-Rich Staged | 2279 kN (Vac) | 452.3 s (Vac) | 4.93% mean error | 🟢 PASS |
| NPO Energomash RD-180 | NPO Energomash | LOX / RP-1 | Ox-Rich Staged (2 chambers) | 4152 kN (Vac) | 338.4 s (Vac) | 5.14% mean error | 🟢 PASS |
| Pratt & Whitney RL10A-4-2 | P&W / Aerojet | LOX / LH2 | Closed Expander | 99.1 kN (Vac) | 451.0 s (Vac) | 3.33% mean error | 🟢 PASS |
| Rocket Lab Rutherford | Rocket Lab | LOX / RP-1 | Electric BLDC Pump | 25.8 kN (Vac) | 311.0 s (Vac) | 2.04% mean error | 🟢 PASS |
| Apollo LMDE | TRW / NASA | N2O4 / MMH | Deep-Throttle Press-Fed | 43.9 kN (Vac) | 311.0 s (Vac) | 2.15% mean error | 🟢 PASS |
Grand Mean Absolute Error Across All 7 Engines: 4.40% (100% first-principles analytical physics).
# Evaluate off-design performance sweep from 100% down to 40% throttle
navronis --subsystem throttle --thrust 30000 --pc 70-
Quadratic Injector Pressure Drop: Injector
$\Delta P$ drops quadratically with throttle fraction:$$\Delta P_{inj}(\tau) = \Delta P_{inj,nom} \cdot \tau^2$$ -
Acoustic Chugging Instability (NASA SP-194): When
$\Delta P_{inj} / P_c < 15%$ , chamber combustion pressure oscillations can feed back into the feed manifolds, triggering catastrophic low-frequency chugging. -
Summerfield Flow Separation Migration: As chamber pressure drops during throttle-down at sea level, nozzle exit pressure
$P_e$ collapses, pulling the separation shock upstream into the bell. -
Coolant Bulk Temperature Rise: Coolant mass flow drops with throttle, causing coolant bulk temperature rise to scale inversely:
$$\Delta T_{bulk} \propto \tau^{-0.2}$$
# Install development dependencies
pip install -e ".[dev]"
# Run all 127 automated verification tests
pytest tests/ -vVerification Suite Overview (127 / 127 Passed in 1.80s — 100% Pass Rate):
-
test_chamber_and_combustion.py: Sonic throat area, isentropic mass flow, Humble contraction ratio, and stay time. -
test_bartz.py: Bartz recovery temperature bounds, convective heat transfer coefficient, and$\sigma$ factor. -
test_chamber_acoustics.py: Exact Bessel roots for 1T, 1R, and 1L acoustic cavity frequencies (NASA SP-194). -
test_injector.py: Torricelli hydraulics, chugging decoupling stiffness ($\Delta P / P_c \ge 0.15$ ), coaxial, swirl, pintle, and doublet atomization. -
test_coolant_and_conduction.py: Fourier radial wall conduction, Haaland friction factor, and Gnielinski coolant heat transfer. -
test_regen_channel.py: Milled channel geometry, perimeter limits, Gnielinski HTC, Haaland friction, fin efficiency, 3-resistance conjugate closure, Darcy-Weisbach$\Delta P$ , thermal stress. -
test_nozzle.py: 1D Area-Mach inversion, Rao 80% bell Bézier contour, Stark (2005) separation, 1976 Standard Atmosphere. -
test_cycle.py: Centrifugal pump hydraulics,$N_s$ impeller classification,$N_{ss}$ cavitation inversion, turbine isentropic expansion, and 6 engine cycles (GG, Expander, ORSC, FRSC, FFSC, Pressure-Fed). -
test_trajectory.py: Transonic wave drag curve$C_D(M)$ , 2D powered ascent gravity turn numerical integration, atmospheric density profile, Max Q magnitude and altitude,$\Delta V$ loss bookkeeping, and orbital deficit. -
test_engine_system.py: MasterEngineSystemsynthesizer end-to-end integration across Methalox, Hydrolox, Kerolox, automated datasheets, and JSON serialization. -
test_engine_deck.py(Day 6): Authoritative flight engine verification decks for Merlin 1D, Raptor 2, RS-25, RD-180, RL10, Rutherford, and LMDE against NASA test-stand datasets. -
test_throttle.py(Day 6): Off-design throttling dynamics, quadratic injector stiffness decay, acoustic chugging decouple trip point, and Summerfield shock migration. -
test_electric_pump.py(Day 6): BLDC electric motor power density ($5.5\text{ kW/kg}$ ), inverter drive efficiency, and Li-ion battery pack energy requirements ($250\text{ Wh/kg}$ ).
Navronis-Propulsion/
├── src/
│ └── kryptonis/
│ └── propulsion_equations/
│ ├── __init__.py # Unified top-level API (v0.6.0)
│ ├── engine_deck.py # Day 6: Authoritative Flight Engine Verification Decks
│ ├── throttle.py # Day 6: Off-Design Throttling & Acoustic Chugging
│ ├── combustor.py # Day 1: CombustorDesign & CombustorResult
│ ├── injector.py # Day 2: 4 Canonical Injector Families
│ ├── regen_channel.py # Day 3: RegenCoolingJacket & Conjugate Wall Solver
│ ├── nozzle.py # Day 4: Rao 80% Bell Nozzle & Standard Atmosphere
│ ├── cycle.py # Day 5/6: Turbomachinery Hydraulics & 6 Power Cycles (incl. Electric)
│ ├── trajectory.py # Day 5: 2D Powered Ascent Gravity Turn Simulator
│ ├── system.py # Day 5: Unified Master EngineSystem Synthesizer
│ ├── chamber.py # NASA SP-125 throat, contraction & volume equations
│ ├── combustion.py # Characteristic velocity c* & stay time
│ ├── bartz.py # Canonical Bartz 1957 convective film coefficient
│ ├── chamber_acoustics.py # NASA SP-194 Bessel acoustic cavity modes
│ ├── profile.py # Axial (x, r) coordinate inner-wall generator
│ ├── plotting.py # Matplotlib 2D cross-section visualizer
│ ├── export.py # Structured JSON & CSV profile exporters
│ ├── units.py # Strongly-typed Result, Status & provenance containers
│ ├── aerodynamics.py # 1D isentropic gas dynamics Area-Mach solver
│ ├── thermal.py # Conjugate heat transfer & thermal marching
│ ├── coolant.py # Supercritical fluid convection & channel friction
│ ├── wall_conduction.py # 1D radial Fourier heat conduction
│ └── cli.py # Standalone terminal CLI (all subsystems + benchmarks)
├── docs/
│ ├── index.html # Interactive Web App (Days 1–6 live simulator)
│ ├── .nojekyll # GitHub Pages static asset bypass
│ └── assets/ # Dimensioned plots and figures
├── examples/
│ ├── 01_thrust_chamber_sizing.py # SP-125 analytical chamber sizing
│ ├── 02_bartz_heat_flux.py # Throat convective heat flux & conduction
│ ├── 03_regenerative_cooling.py # Cooling channel friction & curvature
│ ├── 04_nozzle_divergence_and_separation.py # Gas dynamics & separation limits
│ ├── 05_injector_sizing.py # Sizing the 4 canonical injector families
│ ├── 06_regenerative_cooling_channels.py # Day 3 regenerative cooling jacket sizing
│ ├── 07_turbopump_cycle_power_balance.py # Day 5: 6-cycle turbomachinery power balance
│ ├── 08_integrated_engine_system_and_flight.py # Day 5: Master engine system & ascent flight
│ ├── 09_flight_engine_benchmarks.py # Day 6: Real-engine verification benchmarks (7 engines)
│ └── 10_engine_throttling_and_instability.py # Day 6: Off-design throttling & chugging dynamics
├── tests/ # 127 automated unit tests (100% pass rate)
├── pyproject.toml # PEP 621 standard package build metadata (v0.6.0)
├── LICENSE # Apache-2.0 open-source license
└── README.md # Project documentation and engineering handbook
We welcome collegiate rocket teams, propulsion research groups, and aerospace engineers to contribute reference decks for operational or test-fired liquid rocket engines:
- Create an
EngineReferenceDeckentry insrc/kryptonis/propulsion_equations/engine_deck.pywith primary literature citations (test stand report, AIAA paper, or manufacturer user guide). - Run
pytest tests/test_engine_deck.pyandnavronis --engine <your_engine> --benchmarkto verify analytical error margins. - Submit a Pull Request. We review and merge verified propulsion benchmarks rapidly!
This project is licensed under the Apache License 2.0 — see the LICENSE file for details.