Table of Contents

Home Settings File

Welcome

Welcome to the flowVC documentation.

Input Data Files

Data Format

To use flowVC, you'll need to supply velocity data in binary format. The velocity data typically requires separate files for the velocity field at each time point. A single (Cartesian) or multiple (Unstructured) files define the mesh. These files all share a common prefix, which can be any name you choose and is referred to here as InFilePrefix.

Velocity

If the velocity is defined discretely in time, each time instant should have its own separate file. The velocity data must be equally spaced in time. File names should follow the format InFilePrefix_vel.#.bin, where # is a unique index for each time instant. The difference between successive file time points must be consistent

Each file's content should begin with a time stamp, followed by the velocity vectors at each node.

\begin{equation} t_s \; \underbrace{u_0\; v_0\; w_0}_{\text{node 0}} \underbrace{u_1\; v_1 \; w_1}_{\text{node 1}} ....\; \underbrace{u_{n-1} \; v_{n-1}\; w_{n-1}}_{\text{node n-1}} \end{equation}
  • Cartesian Data: the order should loop over the x-direction in the innermost loop, followed by y, and then z in the outer loop.
  • Unstructured Data: The ordering must align with the nodes specified in the InFilePrefix coordinates.#.bin file.
  • 2D Data: you must still specify a third velocity component, \(w_i\), which can be set to 0.0.
Value Data Type
t double
u,v,w double

Cartesian Mesh

To define a cartesian mesh, the mesh bounds and resolution needs to be defined.

\begin{equation} x_{min} \;\; x_{max} \;\; x_{res} \;\; y_{min} \;\; y_{max}\;\; y_{res} \;\; z_{min} \;\; z_{max} \; \; z_{res} \end{equation}
  • Resolution: Number of nodes in each direction (not intervals)
  • 2D: Set \(z_{min} = z_{max} = 0.0\) and \(z_{res}=1\)
Value Type
min/max double
res int

Unstructured Mesh

The unstructured mesh is defined by three files:

  • Coordinates File : InFilePrefix_coordinates.bin
  • Connectivity File: InFilePrefix_connectivity.bin
  • Adjacency File: InFilePrefix_adjacency.bin
  • Cordinates File
    \begin{equation} n \; \underbrace{x_0\; y_0\; z_0}_{\text{node 0}} \underbrace{x_1\; y_1 \; z_1}_{\text{node 1}} ....\; \underbrace{x_{n-1} \; y_{n-1}\; z_{n-1}}_{\text{node n-1}} \end{equation}
    • n: The the number of points in the data set
    • \(x_i \; y_i \; z_i\): The cordinates of each node
    • 2D: set \(z_i = 0\)
    Value Data Type
    n int
    \(x_i \; y_i \; z_i\) double
  • Connectivity

    The connectivity specifies the indices of the 4 nodes that make up each element. The index of each node is based on coordinates file ordering counting from 0.

    \begin{equation} e\; \underbrace{i_0^0\; i_0^1\; i_0^2\; i_0^3}_{\text{element 0}} \underbrace{i_1^0\; i_1^1\; i_1^2\; i_1^3}_{\text{element 1}} ... \underbrace{i_{e-1}^0\; i_{e-1}^1\; i_{e-1}^2\; i_{e-1}^3}_{\text{element e-1}} \end{equation}
    • e: The number of elements in the data set
    • \(i_i^j\): The index of the j'th node making i'th element in the dataset
    • 2D: \(n_i^3 = -1\)
    Value Data Type
    e int
    \(i_i^j\) int
  • Adjacency

    The adjacency file contains the indices of the adacent elements that share a face with the current element. The index of each element is based on the order of the connectivity file.

    \begin{equation} e\; \underbrace{e_0^0\; e_0^1\; e_0^2\; e_0^3}_{\text{element 0}} \underbrace{e_1^0\; e_1^1\; e_1^2\; e_1^3}_{\text{element 1}} ... \underbrace{e_{e-1}^0\; e_{e-1}^1\; e_{e-1}^2\; e_{e-1}^3}_{\text{element e-1}} \end{equation}
    • Boundary Elements: For faces not shared with other elements set \(e=-1\)
    • 2D: \(e_i^3=-1\)
    • Ordering:
    • Data Type

      e(int): The number of elements in the data set \(e_i^j\) (int): The index of the element that shares the j'th face for the ith element in the dataset. Note if the element face is not shared with another element (i.e. on the edge this is a -1)

Setting File

The input settings are controlled using a settings.in file

For an example input file Click Here

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