cape.pycart.options.Functional: Objective Function Options

This module provides an interface for defining Cart3D’s output functional for output-based mesh adaptation. The options read from this file are written to the $__Design_Info section of input.cntl. Each output function is a linear combination of terms where each term can be a component of a force, a component of a moment, or a point/line sensor.

The following is a representative example of a complex output function.

"Functional": {
    // Term 1: normal force coefficient on "wings"
    "CN": {
        "type": "optForce",
        "force": 2,
        "frame": 0,
        "weight": 1.0,
        "compID": "wings",
        "J": 0,
        "N": 1,
        "target": 0.0
    },
    // Term 2: 0.5 times side force on "entire"
    "CY": {
        "type": "optForce",
        "force": 1,
        "frame": 0,
        "weight": 0.5,
        "compID": "entire"
    },
    // Term 3: 0.001 times point sensor called "p1"
    "p1": {
        "type": "optSensor",
        "weight": 0.001
    }
}

See the JSON “Functional” section for a description of all available options.

See Also:
class cape.pycart.options.Functional.Functional

Dictionary-based interface for Cart3D output functionals

get_optForces()

Return a list of output forces to be used in functional

An output force has the following parameters:

type: {"optForce"}

Output type

compID: str | int

Name of component from which to calculate force/moment

force: {0} | 1 | 2

Axis number of force to use (0-based)

frame: {0} | 1

Force frame; 0 for body axes and 1 for stability axes

weight: {1.0} | float

Weight multiplier for force’s contribution to total

J: {0} | 1

Modifier for the force; not normally used

N: {1} | int

Exponent on force coefficient

target: {0.0} | float

Target value; functional is weight*(F-target)**N

Call:
>>> optForces = opts.get_optForces()
Inputs:
opts: pyCart.options.Options

Options interface

Outputs:
optForces: list (dict)

List of output force dictionaries

Versions:

  • 2014-11-19 @ddalle: First version

get_optMoments()

Return a list of moment coefficients to be used in functional

An output force has the following parameters:

type: {"optMoment""} | "optMoment_point"

Output type

compID: str | int

Name of component from which to calculate force/moment

force: {0} | 1 | 2

Axis number of force to use (0-based)

frame: {0} | 1

Force frame; 0 for body axes and 1 for stability axes

weight: {1.0} | float

Weight multiplier for force’s contribution to total

J: {0} | 1

Modifier for the force; not normally used

N: {1} | int

Exponent on force coefficient

target: {0.0} | float

Target value; functional is weight*(F-target)**N

Call:
>>> optMoments = opts.get_optMoments()
Inputs:
opts: pyCart.options.Options

Options interface

Outputs:
optMoments: list (dict)

List of output moment coefficient dictionaries

Versions:

  • 2015-05-14 @ddalle: First version

get_optSensors()

Return a list of output sensors to be used in functional

An output sensor has the following parameters. The name of the output sensor defines which point/line sensor is used; therefore it must match exactly a point/line sensor as defined in input.cntl.

type: {"optSensor"}

Output type

weight: {1.0} | float

Weight multiplier for force’s contribution to total

J: {0} | 1

Modifier for the force; not normally used

N: {1} | int

Exponent on force coefficient

target: {0.0} | float

Target value; functional is weight*(F-target)**N

Call:
>>> optSensors = opts.get_optSensors()
Inputs:
opts: pyCart.options.Options

Options interface

Outputs:
optSensors: list (dict)

List of output sensor dictionaries

Versions:

  • 2015-05-06 @ddalle: First version