Propulsion

Two main groups: engines (power generators) and propulsors (power consumers).

Pairings:

  • TurbineEngine => JetPropulsor
  • TurbineEngine => PropellerPropulsor
  • PistonEngine => PropellerPropulsor

Any engine can pair with any propulsor.

Engines

Attach to any child of AircraftController (recommend dedicated empty GameObject).

Common fields (AircraftEngineBase):

General

  • Inertia - Spin up/down speed (higher = slower)
  • Min RPM - Minimum engine RPM
  • Max RPM - Maximum engine RPM
  • Stalling Enabled - Can stall below Stall RPM
  • Stall RPM - RPM below which engine stalls

Propulsion

  • Propulsors - List of propulsors powered by this engine (usually one). Power splits if multiple attached.

Throttle

  • Min Throttle - Idle throttle (too low = stalling)
  • Max Throttle - Maximum throttle (usually 1)
  • Throttle Adjustment Speed - Adjustment rate when buttons held

Power & Torque

  • Max Power - Maximum power output
  • Power Curve - Normalized power/RPM (Y: power [0,1], X: RPM [0,1])
  • Internal Drag Torque - Engine losses (higher = spins down faster)
  • Starter Torque - Starter motor torque (higher = faster startup)

Piston Engine

RPM-based power output affected by atmospheric density. Optional forcedInduction component for turbo/supercharger boost. Paired with PropellerPropulsor.

Turbine Engine

RPM-based power curve sensitive to air density/altitude. Paired with JetPropulsor or PropellerPropulsor (turboprop).

Propulsors

Propulsor 'ThrustPoint' and 'ThrustDirection' displayed with gizmos.

Convert engine power to thrust.

Common fields:

  • Thrust Point - Where thrust applies (red sphere)
  • Thrust Direction - Thrust direction (red line)
  • Inertia - Spin up/down speed (higher = slower)
  • Gear Ratio - Engine to propulsor turns (2 = propulsor spins twice per engine turn)
  • Rotation Direction - Propeller rotation direction
  • Reverse Thrust Coefficient - Thrust multiplier in reverse

Propeller Propulsor

Blade element theory thrust calculation based on pitch, RPM, velocity, airfoil characteristics.

Features:

  • Fixed or variable pitch (constant-speed)
  • Auto pitch control for target RPM
  • Manual pitch control
  • Blade feathering
  • Windmilling detection

Performance depends on blade geometry (bladeCount, bladeWidth), pitch, airfoilProfile. Typical efficiency: 75-85%.

Jet Propulsor

Direct thrust (turbofan/turbojet) without propeller. Affected by RPM and altitude.

  • maxThrust - Max thrust at sea level (N)
  • thrustRPMCurve - Thrust vs RPM (0-1)
  • thrustElevationCurve - Thrust vs altitude/density

Thrust from RPM and atmospheric density. Paired with TurbineEngine.