Aero.Aircraft.CompositeCoefficient Class

Namespace: Aero

Create composite aerodynamic coefficient

Since R2023b

Description

Aero.Aircraft.CompositeCoefficient defines an aerodynamic coefficient. You can specify this coefficient with the sum or product of multiple lookup tables and numeric values. The Aero.Aircraft.CompositeCoefficient object is used as a value for the Aero.FixedWing.Coefficient object.

Class Attributes

Abstract	false
ConstructOnLoad	false
HandleCompatible	false
Hidden	false
Sealed	true
RestrictsSubclassing	true

For information on class attributes, see Class Attributes.

Creation

Description

Aero.Aircraft.CompositeCoefficient(valueCell) creates a composite aerodynamic coefficient with a cell array of Simulink.LookupTable objects, scalar numeric values, or Aero.Aircraft.CompositeCoefficient objects, valueCell.

Aero.Aircraft.CompositeCoefficient(valueCell,functionHandle) uses a specification of how the cell array members are combined.

Aero.Aircraft.CompositeCoefficient(___,stateProperty) creates a composite aerodynamic coefficient with a string array of Aero.FixedWing.State properties. The object uses a specification, functionHandle, of how the valueCell array and stateProperty members are combined.

Input Arguments

valueCell — Collection of Simulink.LookupTable objects, scalar numeric, Aero.Aircraft.CompositeCoefficient objects

row or column cell array

Collection of Simulink.LookupTable objects, scalar numeric, Aero.Aircraft.CompositeCoefficient objects, specified as a row or column cell array.

functionHandle — Function handle action applied to valueCell cell array members

@prod (default) | @sum | @abs | @max | @min | @mean | @power | @mod | @exp | @sin | @cos | @tan | @asin | @acos | @atan | @atan2

Function handle combination action applied to valueCell cell array and stateProperty string array members, specified as @prod, @sum, @abs, @max, @min, @mean, @power, @mod, @exp, @sin, @cos, @tan, @asin, @acos, @atan, or @atan2.

stateProperty — Properties defined in custom array of Aero.FixedWing.State

string array of Aero.FixedWing.State properties

Properties defined in custom Aero.FixedWing.State, specified as a string array of Aero.FixedWing.State properties.

Example: ["Alpha","DynamicPressure","P"]

Data Types: string

Properties

ValueCell — Collection of Simulink.LookupTable objects, scalar numeric, Aero.Aircraft.CompositeCoefficient objects

row or column cell array

Collection of Simulink.LookupTable objects, scalar numeric, Aero.Aircraft.CompositeCoefficient objects, specified as a row or column cell array.

Attributes:

GetAccess	public
SetAccess	private

CoefficientImpl — Function handle action applied to valueCell cell array members

@prod (default) | @sum | @abs | @max | @min | @mean | @power | @mod | @exp | @sin | @cos | @tan | @asin | @acos | @atan | @atan2

Function handle combination action applied to valueCell cell array and stateProperty string array members, specified as @prod, @sum, @abs, @max, @min, @mean, @power, @mod, @exp, @sin, @cos, @tan, @asin, @acos, @atan, or @atan2.

Attributes:

GetAccess	public
SetAccess	private

StateProperty — Properties defined in custom array of Aero.FixedWing.State

string array of Aero.FixedWing.State properties

Properties defined in custom Aero.FixedWing.State, specified as a string array of Aero.FixedWing.State properties.

Example: ["Alpha","DynamicPressure","P"]

Attributes:

GetAccess	public
SetAccess	private

Methods

Public Methods

calculate

Calculate numeric aerodynamic force or moment of Aero.Aircraft.CompositeCoefficient for Aero.FixedWing.State object

Examples

Create a Nonlinear Aerodynamic Lift and Drag Coefficient Model Using CompositeCoefficient

This example demonstrates how to construct a nonlinear aerodynamic lift and drag coefficient model. The drag coefficient is modeled as the sum of a profile drag lookup table (which varies with angle of attack) and induced drag.

Create a Simulink.LookupTable (Simulink) object for the lift coefficient lutCL and define table data. The lift coefficient ranges from a minimum of -0.9 to a maximum of 1.3 and includes stall.

alpha_deg = [-15 -12 -10 -5 0 5 10 12 15 18];
alpha_rad = deg2rad(alpha_deg);
cl_vals  = [-0.7 -0.9 -0.6 -0.2 0.0 0.6 1.1 1.25 1.3 1.1];

lutCL = Simulink.LookupTable;
lutCL.Table.Value = cl_vals;
lutCL.Breakpoints(1).Value = alpha_rad;
lutCL.Breakpoints(1).FieldName = "Alpha";

Create a Simulink.LookupTable object for the profile drag coefficient called lutCDp using the same angle of attack breakpoints.

cdp_vals = 0.01 * [4, 2.92, 1.85, 1.09, 1, 1.09, 1.85, 3.6, 4.4, 5.2];

lutCDp = Simulink.LookupTable;
lutCDp.Table.Value = cdp_vals;
lutCDp.Breakpoints(1).Value = alpha_rad;
lutCDp.Breakpoints(1).FieldName = "Alpha";

Create Aero.Aircraft.CompositeCoefficient objects for the induced drag, $$C_{D_i}=\frac{C_L^2}{\pi ARe}$$, and the total drag, $$C_D=C_{D_p}+C_{D_i}$$.

AR = 8;
e = 0.85;

CDi = Aero.Aircraft.CompositeCoefficient({lutCL, lutCL, 1/(pi*AR*e)}, @prod, []);
CD = Aero.Aircraft.CompositeCoefficient({lutCDp, CDi}, @sum, [])

CD = 
  CompositeCoefficient with properties:

          ValueCell: {[1×1 Simulink.LookupTable]  [1×1 Aero.Aircraft.CompositeCoefficient]}
    CoefficientImpl: @sum
      StateProperty: [1×0 string]

Compute the coefficient values at a given angle of attack using the calculate method.

state = Aero.FixedWing.State();
state.Alpha = deg2rad(5);
CL_value5 = Aero.Aircraft.CompositeCoefficient.calculate(lutCL, state)

CL_value5 = 
0.6000

CD_value5 = Aero.Aircraft.CompositeCoefficient.calculate(CD, state)

CD_value5 = 
0.0278

Version History

Introduced in R2023b

R2024a: Use New Aero.Aircraft.CompositeCoefficient Class Argument, Method, and Function Handles

The Aero.Aircraft.CompositeCoefficient class has these changes:

• stateProperty argument allows you to create a composite aerodynamic coefficient with a string array of Aero.FixedWing.State properties.

• The new calculate method allows you to calculate numeric aerodynamic force or moment of Aero.Aircraft.CompositeCoefficient for Aero.FixedWing.State. You can use the numeric aerodynamic force or moment to check the validity of the defined Aero.Aircraft.CompositeCoefficient.

• These function handles are now available for functionHandle:

  • @abs

  • @max

  • @min

  • @mean

  • @power

  • @mod

  • @exp

  • @sin

  • @cos

  • @tan

  • @asin

  • @acos

  • @atan

  • @atan2

• New properties:

  • ValueCell

  • CoefficientImpl

  • StateProperty