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Live · v1.3

AgniCycle™
Engine Simulator

A transient 0-D thermodynamic solver resolving pressure, temperature, and emissions at 0.25° crank-angle resolution across all four strokes — 2,881 equations per cylinder, finishing in under 20 ms. In your browser.

No install Peer-validated physics Runs in any browser
agnicycle · cycle_simulator · diesel · 1500 rpm
< 20ms
Full transient cycle
2,881
Equations per cylinder
0.25°
Crank-angle resolution
720°
Full CA sweep
12+
Calibrated fuel models

Research-grade physics,
zero setup time

Every model is peer-validated. Every parameter is adjustable. No black-box sliders.

🔥
Double-Wiebe Combustion
Mixed premixed + diffusion kinetics. Covers spark-ignition flame propagation and diesel diffusion simultaneously — not a compromise model.
📊
Live P-V & T-S Diagrams
Interactive diagrams that update in real-time as you sweep parameters. Export as SVG or PNG for publications.
Three-Zone Thermodynamics
Unburned reactants, flame front, and burned products solved simultaneously. First-Law energy partition at every crank-angle step.
🧪
Knock Prediction
Livengood-Wu knock integral with fuel-specific auto-ignition chemistry. Identify knock-limited spark advance before building hardware.
🌿
NOₓ & Emissions
Extended Zeldovich thermal NOx — cycle-accurate, not post-processed. Full emissions map across RPM and load.
🎓
Researcher & Instructor Modes
Switch between deep research configuration with all parameters exposed, and curriculum-preset layout for teaching thermodynamics.

12+ calibrated fuel models

JANAF/NASA polynomial thermochemistry — no hardcoded k values, no simplified assumptions.

Hydrogen H₂ Ammonia NH₃ DME E85 Diesel Iso-octane CNG Gasoline Biodiesel Ethanol Methanol E10

Not a lookup table — a real combustion solver

Every pressure trace comes from integrating real thermodynamics across the cycle, not interpolating between pre-baked results.

// Wiebe Heat Release Rate
The rate at which fuel mass fraction x_b burns with crank angle θ — integrated alongside the first law of thermodynamics to produce the pressure trace you see on every run.

That heat-release rate feeds directly into a first-law energy balance on the cylinder control volume, solved across 2,881 crank-angle steps per cycle using JANAF/NASA polynomial thermochemistry for each fuel — not constant specific heats.

2,881
Crank-angle steps
12+
Calibrated fuel models
0-D
Fast, not approximate

Same solver, different reasons to open it

🎓
Students
Build intuition for how compression ratio, fuel choice, and timing actually move the pressure trace — instantly, in a browser tab.
🔬
Researchers
Pre-screen a parameter sweep before committing HPC hours to the 3-D CFD cases that actually need it.
⚙️
Industry Engineers
Get a defensible first-order feasibility answer on a fuel or timing change the same day you ask the question.
Scroll The Cycle

Four strokes. One controlled burn.

Scroll to turn the crank — the log p · log V trace is computed live from the same first-law energy balance this simulator solves.

Intake Compression Power Exhaust
IN EX TDC BDC
log V → log p →

The intake valve opens and the descending piston draws in fresh charge at ≈0.95 bar — the flat lower line of the loop.

Both valves seal. The rising piston compresses the charge polytropically — a straight line in log-log space, pressure climbing toward autoignition.

Fuel burns following the Wiebe function above; pressure spikes past 60 bar. The loop area is the net work — the same convention as the arrows in our logo.

The exhaust valve opens at BDC, pressure collapses, and the rising piston clears the burned gas. Ready to repeat.

⇣ scroll to turn the crank

Ready to run your first simulation?

No install. Works on any browser. Your first run takes under 60 seconds from sign-up.

Launch Engine Simulator
Runs in any browser No install Instant access