WOLFRAM SYSTEM MODELER

ConventionalPropulsion

Interface for conventional propulsion model

Diagram

Wolfram Language

In[1]:=
SystemModel["Aircraft.Physical.FixedWing.Parts.Propulsions.Interfaces.ConventionalPropulsion"]
Out[1]:=

Information

This partial model models a conventional propulsion system with engines mounted on the wings, fuselage or vertical tail, and this extends the PropulsionBase partial model. The complete conventional propulsion system models, namely the TurbofanPropulsion, TurbojetPropulsion, TurbopropPropulsion, PistonPropulsion and ElectricPropulsion models extend this partial model. 

In this partial model, the position and orientation of the engine are defined. Additionally, the model for the energy storage is included, and the fuel or energy consumption of all engines is summed here to feed it as an input for the energy storage model.

The constraints of the conventional propulsion models are:

  • All engines need to be of same type and model.
  • The allowed number of engines is from 0 (for glider) to 4.
  • If the number of engines is three, the middle engine is mounted on the vertical tail.
  • Only one engine can be mounted on the fuselage centerline.
  • Engines cannot be mounted on both the main wing and the fuselage.
  • The orientation of the engines is fixed (no thrust vectoring).

The diagram view of this model shows the numbering convention of the engines that is used throughout the library.

Parameters

The number of the engines, if its wing mounted, and their type are defined in the AircraftBase model. Depending on the number of engines and whether the engines are mounted on the main wing or on the fuselage, the editing of the inapplicable parameters will be disabled. For example, for an aircraft with two engines mounted on the main wing, the editing of the parameters xEng, yEngOuter, zTauMid and kappaMid is disabled.

If engines are mounted on the main wing (wingMounted = true), their location along the body x axis is calculated based on the wing geometry, whereas the position along the body y and z axes are defined by the yEngInner / yEngOuter and zTau parameters, respectively. For an aircraft with four engines mounted on the main wing, the zTau parameter refers to the average z coordinate of the inner and outer engines, and the z coordinates of the individual engines are solved based on the main wing dihedral angle. If engines are mounted on the fuselage (wingMounted = false), no calculations are performed for solving for their positions, but they are defined by the xEng, yEngInner / yEngOuter and zTau parameters. If the number of engines is 3, the position of the middle engine (#1) is assumed to be on the vertical tail, and its position on body x axis is solved based on the vertical tail geometry, and its location on the body z axis is defined by the zTauMid parameter. The parameters kappa and kappaMid are used to define the engine thrust line angle, i.e. the orientation of the engines around the body y axis. 

A surface roughness height to be used for all engine nacelles can be entered at the Engine Geometry tab. By default, the global surface roughness height defined in the AircraftBase model is used for all nacelles.

The remaining parameters listed in the Propagated Properties tab are propagated from the AircraftBase as the propulsion system is compiled in the propulsion system model and thus they can and should be left unchanged.

Propulsion Mass Properties and Drag

This partial model also has the equations to solve for the total mass, center of mass location, inertia tensor and drag force of the entire propulsion system, which are also used by the AircraftBase model to solve for the mass properties and drag force of the entire aircraft model.

Parameters (42)

kSkinNac

Value:

Type: Length (m)

Description: Nacelle surface roughness height

CADshapes

Value:

Type: Boolean

Description: true, if external CAD files are used for animation

convProp

Value: true

Type: Boolean

Description: =true, if conventional propulsion

weightEst

Value:

Type: Boolean

Description: true, if weight estimation method is used for masses, center of mass location and inertia tensor

SrefWing

Value:

Type: Area (m²)

Description: Main wing reference area

nEng

Value: 5

Type: Integer

Description: Number of engines

T0

Value:

Type: Temperature (K)

Description: Temperature at sea-level

rho0

Value:

Type: Density (kg/m³)

Description: Air density at sea-level

p0

Value:

Type: Pressure (Pa)

Description: Static pressure at sea-level

gammaAir

Value:

Type: Real

Description: Adiabatic index for air

bWing

Value:

Type: Length (m)

Description: Main wing span

engineType

Value:

Type: Integer

Description: Type of engine (0 = piston, 1 = turboprop, 2 = turbojet, 3 = turbofan, 4 = electric)

wingMounted

Value:

Type: Boolean

Description: true, if engines are mounted on the main wing

xEng

Value:

Type: Length (m)

Description: Fuselage mounted engine / Single engine rear end x-location from fuselage reference point (positive x-axis towards nose)

yEngInner

Value: if nEng == 2 then bWing / 4 else bWing / 3

Type: Length (m)

Description: Inner engines y-coordinate w.r.t. fuselage centerline

yEngOuter

Value: bWing / 6

Type: Length (m)

Description: Outer engines y-coordinate w.r.t. fuselage centerline

zTau

Value: 0

Type: Length (m)

Description: Thrust line z-coordinate w.r.t. fuselage reference point for side (#2-5) engines and single engine

zTauMid

Value: zTau

Type: Length (m)

Description: Thrust line z-coordinate w.r.t. fuselage reference point for middle (#1) engine

kappa

Value: 0

Type: Angle (rad)

Description: Engine thrust line angle for side (#2-5) engines and single engine

kappaMid

Value: 0

Type: Angle (rad)

Description: Engine thrust line angle for middle (#1) engine

kappaEng1

Value: if nEng == 1 then kappa else if nEng == 3 then kappaMid else 0

Type: Angle (rad)

Description: Engine thrust line angle for Engine 1

tauWing

Value:

Type: Real

Description: Ratio of thickness-to-chord ratios at the main wing tip and root

xCMdry

Value:

Type: Length (m)

Description: Aircraft center of mass x-coordinate w.r.t. fuselage reference point (with total mass for electric aircraft and gliders, positive x-axis towards nose)

wFus

Value:

Type: Length (m)

Description: Fuselage maximum width

hFus

Value:

Type: Length (m)

Description: Fuselage maximum height

cWingRoot

Value:

Type: Length (m)

Description: Main wing root chord (where wing intersects with fuselage)

cWingTip

Value:

Type: Length (m)

Description: Main wing tip chord

tWingRoot

Value:

Type: Length (m)

Description: Main wing root thickness

tWingTip

Value:

Type: Length (m)

Description: Main wing tip thickness

xWingRootLE

Value:

Type: Length (m)

Description: Main wing root leading edge x-coordinate w.r.t. fuselage reference point (positive x-axis towards nose)

zWingRootLE

Value:

Type: Length (m)

Description: Main wing root leading edge z-coordinate w.r.t. fuselage reference point (positive z-axis towards ground)

lambdaWing

Value:

Type: Angle (rad)

Description: Main wing sweep angle at 1/4 chord

gammaWing

Value:

Type: Angle (rad)

Description: Main wing dihedral angle

iWing

Value:

Type: Angle (rad)

Description: Main wing incidence angle

TRwing

Value:

Type: Real

Description: Main wing taper ratio

xWingAC

Value:

Type: Length (m)

Description: Main wing aerodynamic center from wing leading edge at mean chord (positive x-axis towards nose)

yWingAC

Value:

Type: Length (m)

Description: Main wing aerodynamic center from fuselage centerline (y-coordinate w.r.t. fuselage centerline of mean chord)

lambdaWingLE

Value:

Type: Angle (rad)

Description: Main wing leading edge sweep angle

lambdaWingHC

Value:

Type: Angle (rad)

Description: Main wing half-chord sweep angle

bVT

Value:

Type: Length (m)

Description: Vertical tail span

lVTcm

Value:

Type: Length (m)

Description: Vertical tail arm length (from aircraft center of mass to vertical tail 1/4 chord)

rEng1

Value: if nEng == 3 then {xCMdry - lVTcm - bVT * (3 / 4), 0, zTauMid} else if nEng == 1 then {xEng, 0, zTau} else {0, 0, 0}

Type: Length[3] (m)

Description: Location of engine 1 rear end w.r.t. fuselage reference point

Inputs (1)

flightData

Type: FlightData

Description: Global flight data variables

Connectors (2)

aircraftRP

Type: Frame_b

Description: Connector to aircraft reference point

deltaThrotCmd

Type: RealInput[nEng]

Description: Engine throttle commands

Components (18)

flightData

Type: FlightData

Description: Global flight data variables

energyStorage

Type: EnergyStorage

Description: Model for energy storage

rotEng2

Type: FixedRotation

Description: Engine 2 thrust line angle (enabled if number of engines = 2 or 3 or 4)

rotEng3

Type: FixedRotation

Description: Engine 3 thrust line angle (enabled if number of engines = 2 or 3 or 4)

rotEng4

Type: FixedRotation

Description: Engine 4 thrust line angle (enabled if number of engines = 4)

rotEng5

Type: FixedRotation

Description: Engine 5 thrust line angle (enabled if number of engines = 4)

translEng1

Type: FixedTranslation

Description: Location of engine 1 rear end w.r.t. fuselage reference point

translEng2

Type: FixedTranslation

Description: Location of engine 2 rear end w.r.t. fuselage reference point

translEng3

Type: FixedTranslation

Description: Location of engine 3 rear end w.r.t. fuselage reference point

translEng4

Type: FixedTranslation

Description: Location of engine 4 rear end w.r.t. fuselage reference point

translEng5

Type: FixedTranslation

Description: Location of engine 5 rear end w.r.t. fuselage reference point

engineC

Type: Engine

Description: Model for engine 1

engineD

Type: Engine

Description: Type of engine model used in the propulsion system

engineB

Type: Engine

Description: Type of engine model used in the propulsion system

engineE

Type: Engine

Description: Type of engine model used in the propulsion system

engineA

Type: Engine

Description: Type of engine model used in the propulsion system

sumConsumption

Type: Sum

Description: Summing of fuel / battery energy consumption

rotEng1

Type: FixedRotation

Description: Engine 1 thrust line angle

Used in Components (1)

AircraftBase

Aircraft.Physical.FixedWing.Interfaces

Interface for a complete aircraft model

Extended by (5)

ElectricPropulsion

Aircraft.Physical.FixedWing.Parts.Propulsions

Electric propulsion (model specific parameters not set)

PistonPropulsion

Aircraft.Physical.FixedWing.Parts.Propulsions

Piston propulsion (model specific parameters not set)

TurbopropPropulsion

Aircraft.Physical.FixedWing.Parts.Propulsions

Turboprop propulsion (model specific parameters not set)

TurbojetPropulsion

Aircraft.Physical.FixedWing.Parts.Propulsions

Turbojet propulsion (model specific parameters not set)

TurbofanPropulsion

Aircraft.Physical.FixedWing.Parts.Propulsions

Turbofan propulsion (model specific parameters not set)