FFTGradientSquare

Tensor gradient.

Compute the Laplacian (gradient squared) of a real space tensor via reciprocal space spectral gradient. Internally this involves a forward and a backward Fourier transform and invetwee a multiplication with .

Overview

Computes |\nabla u|^2 using spectral derivatives: forward FFT, multiply by wave vectors, and sum component squares. Provide the source field via "input" and the destination via "buffer".

Example Input File Syntax

[TensorComputes<<<{"href": "../../syntax/TensorComputes/index.html"}>>>]
  [Initialize<<<{"href": "../../syntax/TensorComputes/Initialize/index.html"}>>>]
    [grad_sq]
      type = FFTGradientSquare<<<{"description": "Tensor gradient.", "href": "FFTGradientSquare.html"}>>>
      buffer<<<{"description": "The buffer this compute is writing to"}>>> = grad_sq
      input<<<{"description": "Input buffer name"}>>> = s
    []
  []
[]
(test/tests/gradient/gradient_square.i)

Input Parameters

  • bufferThe buffer this compute is writing to

    C++ Type:std::string

    Controllable:No

    Description:The buffer this compute is writing to

  • inputInput buffer name

    C++ Type:std::string

    Controllable:No

    Description:Input buffer name

Required Parameters

  • factor1Prefactor to the gradient square

    Default:1

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Prefactor to the gradient square

  • input_is_reciprocalFalseInput buffer is already in reciprocal space

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Input buffer is already in reciprocal space

Optional Parameters

  • control_tagsAdds user-defined labels for accessing object parameters via control logic.

    C++ Type:std::vector<std::string>

    Controllable:No

    Description:Adds user-defined labels for accessing object parameters via control logic.

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Controllable:No

    Description:Set the enabled status of the MooseObject.

Advanced Parameters

Input Files