Diesel Engine Runaway Phenomenon

NGSS HS-PS3-2: Macroscopic energy as a combination of microscopic motion and position.

Operator Controls

Fuel Injection (Chemical Potential Energy) 0%

Controls intentional diesel fuel entering the cylinder.

Air Intake Valve (Throttle) 100%

Diesels are air-throttled. Normally open, can be choked.

Diagnostic Tools

System Load

Applying a heavy load will normally lower RPM.

Engine RPM

Redline: 4500

Engine Temp (°C)

Normal: ~90°C

System Status

IDLE

Cylinder Particle View

Blue: Air Molecules Yellow: Diesel Fuel

Energy Conversion (Potential -> Kinetic)

Mission Briefing

Welcome to the heavy-duty diesel mechanics diagnostic bay. Your task is to investigate a dangerous and dramatic phenomenon known as a Diesel Runaway.

Unlike gasoline engines which use a spark plug and throttle body to control air/fuel, diesel engines pull in maximum air at all times. They compress that air until it gets so hot that injected fuel ignites spontaneously. Engine speed is normally controlled purely by how much fuel is injected.

Your Task:

Start the engine and observe normal operation by increasing fuel injection.
Trigger the "Mystery Fault" and observe what happens to the RPM and Temperature.
Figure out what is causing the runaway (where is the extra energy coming from?).
Figure out how to stop it using the available controls before the engine destroys itself.

NGSS Connection (HS-PS3-2): Notice how the chemical potential energy stored in the molecular bonds of the fuel (and the mystery fluid) is rapidly converted into the macroscopic kinetic energy of the moving pistons, manifesting as dangerous RPM levels.