WOLFRAM SYSTEM MODELER
PrattWhitneyJT4A11Turbojet engine: Pratt & Whitney JT4A-11 |
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Diagram
Wolfram Language
In[1]:=
SystemModel["Aircraft.Physical.FixedWing.Parts.Propulsions.Engines.TurbojetEngines.PrattWhitneyJT4A11"]
Out[1]:=
Information
This model extends the TurbojetEngine model and contains the parameters of the Pratt & Whitney JT4A-11 engine.
References for Engine Parameter Values
[1] Wikipedia. (2022). "Pratt & Whitney J75". [online]
Available at: https://en.wikipedia.org/wiki/Pratt_%26_Whitney_J75#Specifications_(JT4A-11) [Accessed 26 Oct. 2022].
Parameters (26)
| weightEst |
Value: Type: Boolean Description: true, if weight estimation method is used for masses, center of mass location and inertia tensor |
|---|---|
| bWing |
Value: Type: Length (m) Description: Main wing span |
| SrefWing |
Value: Type: Area (m²) Description: Main wing reference area |
| CADshapes |
Value: Type: Boolean Description: true, if external CAD files are used for animation |
| negThrust |
Value: 0.2 Type: Real Description: Maximum negative thrust (0 to 1 of thrust available) |
| T0 |
Value: Type: Temperature (K) Description: Temperature at sea-level |
| p0 |
Value: Type: Pressure (Pa) Description: Static pressure at sea-level |
| gammaAir |
Value: Type: Real Description: Adiabatic index for air |
| Tstatic |
Value: 77840 Type: Force (N) Description: Static thrust of one engine at sea level |
| TSFC |
Value: 2.1e-05 Type: ThrustSpecificFuelConsumption (kg⋅N⁻¹⋅s⁻¹) Description: Thrust-specific fuel consumption in cruise |
| altEngDes |
Value: 11000 Type: Height (m) Description: Engine design altitude |
| machEngDes |
Value: 0.82 Type: Real Description: Engine design Mach number |
| kSkinNac |
Value: Type: Length (m) Description: Nacelle surface roughness height |
| mNac |
Value: if negThrust > 0 then 0.345 * 1.18 * mEngDry else 0.345 * mEngDry Type: Mass (kg) Description: Nacelle mass |
| mPyl |
Value: 0.574 * mEngDry ^ 0.736 Type: Mass (kg) Description: Pylon mass |
| mEngDry |
Value: 2313.3 Type: Mass (kg) Description: Engine dry mass |
| mEngInstalled |
Value: mEngDry + mNac + mPyl Type: Mass (kg) Description: Installed engine mass |
| xEngCM |
Value: lNac / 2 Type: Length (m) Description: Engine center of mass x-coordinate w.r.t. engine rear end |
| IxxEng |
Value: mEngInstalled * (dNac / 2) ^ 2 / 2 Type: MomentOfInertia (kg⋅m²) Description: Engine roll moment of inertia |
| IyyEng |
Value: mEngInstalled * (dNac / 2) ^ 2 / 4 + mEngInstalled * lNac ^ 2 / 12 Type: MomentOfInertia (kg⋅m²) Description: Engine pitch moment of inertia |
| IzzEng |
Value: mEngInstalled * (dNac / 2) ^ 2 / 4 + mEngInstalled * lNac ^ 2 / 12 Type: MomentOfInertia (kg⋅m²) Description: Engine yaw moment of inertia |
| dNac |
Value: 4 * (0.0625 + 1 / (4 * sqrt(2)) * max(1.730 * log(max(Tstatic / 1000, 1)) - Modelica.Constants.pi, 0) ^ 0.5) Type: Length (m) Description: Nacelle diameter |
| lNac |
Value: 5 * (Tstatic / 1000) ^ 0.9839 / (6 * Modelica.Constants.pi * (1.730 * log(max(Tstatic / 1000, 1)) - Modelica.Constants.pi)) Type: Length (m) Description: Nacelle length |
| SwetNac |
Value: 2 * Modelica.Constants.pi ^ 2 * 0.2028 * dNac * ((0.20571 * lNac ^ 2 + 0.04661 * dNac ^ 2) ^ 0.5 + (0.1853 * lNac ^ 2 + 0.07557 * dNac ^ 2) ^ 0.5 - (0.005077 * lNac ^ 2 + 0.01611 * dNac ^ 2) ^ 0.5 - (0.01651 * lNac ^ 2 + 0.03666 * dNac ^ 2) ^ 0.5) Type: Area (m²) Description: Nacelle wetted area |
| FFnac |
Value: 1.17 * (1 + 0.35 * (dNac / max(lNac, 0.01))) Type: Real Description: Nacelle form factor |
| throtR |
Value: TengDes / T0 * (1 + (gammaAir - 1) / 2 * machEngDes ^ 2) Type: Real Description: Throttle ratio |
Inputs (1)
| flightData |
Type: FlightData Description: Global flight data variables |
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Connectors (3)
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deltaThrotCmd |
Type: RealInput Description: Throttle position command |
|---|---|---|
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engineRP |
Type: Frame_b Description: Connector to engine reference point |
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yConsumption |
Type: RealOutput Description: Consumed electric energy or fuel in an engine |
Components (15)
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flightData |
Type: FlightData Description: Global flight data variables |
|---|---|---|
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energySystem |
Type: FuelSystemThrustSpecific Description: Model to calculate the consumed electric energy or fuel in an engine |
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thrustEngine |
Type: WorldForce Description: Engine net thrust |
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engShape |
Type: FixedShape Description: Engine visualization |
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thrustAvailable |
Type: RealExpression Description: Thrust available of one engine |
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engineThrustDmd |
Type: Product Description: Thrust demand for one engine |
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engineDynamics |
Type: CriticalDamping Description: Simplified model of the engine dynamics |
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throttleOnGround |
Type: Limiter Description: Limits the throttle from maximum negative thrust to 1 once on the ground |
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dragNacelle3D |
Type: RealExpression[3] Description: Drag due to one nacelle |
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dragNacelle |
Type: WorldForce Description: Drag of nacelle |
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translEng |
Type: FixedTranslation Description: Translation from engine rear end to the point where thrust and drag are acting on (currently no translation) |
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bodyEng |
Type: Body Description: Mass and inertia of engine |
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switch |
Type: Switch Description: Switch between two Real signals |
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throttleInAir |
Type: Limiter Description: Limits the throttle from 0 to 1 once airborne |
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onGround |
Type: BooleanExpression Description: Boolean expression for indicating aircraft being on ground |