Stoner Physics
COLLECTION 01 / AIR-BREATHING ENGINES

Inside the J58.

Air. Fuel. Fire. Open the Blackbird’s engine and see them work together.

Mach 3+DESIGN FLIGHT REGIME
9 + 2COMPRESSOR + TURBINE STAGES
SR-71ICONIC APPLICATION
Preparing the engine…
PRATT & WHITNEY J58AFTERBURNING TURBOJET
THRUST—kN
FUEL—kg/s
INTAKEEXHAUST
SECTION VIEW · 50% OPENDRAG TO ORBIT · SCROLL TO ZOOM
ClosedHalf section
Incoming airFuel sprayCombustionBleed bypass

Air is tinted to reveal its motion. Procedural flow and flames; performance is estimated.

PUT THE ENGINE TO WORK

Your hand on the throttle.

LIVE EDUCATIONAL ESTIMATES
PRESETS
RUNNING

Estimated steady-state cycle at the current shaft speed.

NET THRUST—kN / engine
FUEL FLOW—kg / second
SHAFT SPEED—% modeled reference
TURBINE EXHAUST—°C · total temperature
AIR MASS FLOW—kg / second
COMPRESSOR RATIO—outlet / inlet pressure
SPECIFIC FUEL USE—kg / (kN · hour)
NOZZLE EXIT AREA—m² · calculated
Under the hood: station data, equations & assumptions

Total (stagnation) values, not metal temperatures. All values below are model outputs.

StationTemperaturePressure

One linked thermodynamic cycle

F = ṁexitVexit − ṁairVflight + (pexit − pambient)Aexit

Assumptions: standard-atmosphere approximation; 8.8 reference compressor ratio; 136 kg/s reference airflow; compressor efficiency 84%; turbine efficiency 90%; burner efficiency 98%; nozzle efficiency 95%; fuel heating value 43 MJ/kg; maximum turbine-inlet target 1,360 K; maximum reheat target 2,100 K.

The efficiencies, temperature limits, flow normalization, bleed schedule and off-design relationships are educational assumptions. No manufacturer maps, inlet-unstart model, component limits, cooling network or validated transient dynamics are included. Zero fuel commands report zero thrust; windmilling is excluded.

NASA · gas turbine cycle equations ↗
THE BLACKBIRD'S SECRET

One engine.
Two routes for the air.

Most air follows the engine's central path. At high flight speed, the J58 also sends some compressed air through six unmistakable external ducts toward the afterburner.

Explore both routes, then click a part to discover what it contributes.

Air follows the central path.

J58 ENGINE EXPLORER More free tools · Privacy
EXHIBIT NOTES

A real engine.
A transparent model.

This original educational reconstruction depicts the Pratt & Whitney J58. Its defining architecture follows public museum and NASA references, with mechanical layout checked against the J58 internal and external detail drawings in Peter Law’s 2013 propulsion presentation.

What is documented

Nine compressor stages, two turbine stages, eight combustion cans, a common shaft, and six bleed-bypass ducts from the fourth compressor stage toward the afterburner. The reference detail drawing also identifies four afterburner spray rings, four flameholders and four exhaust-nozzle actuators. The J58 powered the SR-71, A-12 and YF-12.

What is approximated

Blade profiles and counts within each row, nozzle petal count, dimensions, pipe bends, accessory placement, nozzle linkages and surface finishes are visual reconstructions. This is not a scanned engine or manufacturing CAD. The SR-71's separate inlet spike, nacelle and airframe ejector nozzle are outside this model.

How to read the motion

Rotors share an illustrative shaft speed. The air is given a blue tint so its otherwise invisible motion can be seen. Pale droplets show atomized fuel entering the combustion cans and reheat section. Three-dimensional procedural density fields show mixing, flame motion and the exhaust plume. These are illustrative volumes, not computed fluid dynamics, measured flame shapes, or a temperature color scale. Shock-like cells in the reheat plume are illustrative; the aircraft ejector nozzle is not modeled. The operating controls drive a simplified thermodynamic cycle. Its thrust, fuel use and station data are educational estimates rather than validated J58 performance predictions. The cutaway removes the front casing and stationary structure while leaving moving parts visible.

References

Independent educational exhibit. Not affiliated with Pratt & Whitney, NASA or the museums. Renderer: Three.js, MIT license.