Installation Instructions

FLOWUnsteady is developed in the Julia programming language, which is a modern, high-level, dynamic programming language for high-performance computing. For visualization and postprocessing, FLOWUnsteady uses ParaView, which is an open-source software for scientific and HPC visualization.

The following instructions walk you through how to install Julia, ParaView, and FLOWUnsteady.

Julia

• Download and install Julia: julialang.org (currently we are supporting up to Julia v1.10, so we recommend using v1.10.2 or v1.6.7 LTS )
• Add Julia to user-level bin folder

  sudo ln -s /[user-specific-path/Julia-1.x.x]/bin/julia /usr/local/bin/julia

  Replace /[user-specific-path/Julia-1.x.x]/ with the path where Julia got installed. For instance, in MacOS the full path looks like this: /Applications/Julia-1.10.app/Contents/Resources/julia/bin/julia

If you were successfull, typing the following in the terminal will launch the Julia REPL:

julia

ParaView

• Download and install ParaView: paraview.org
• Add ParaView to user-level bin folder

  sudo ln -s /[user-specific-path/ParaView-5.x.x]/paraview /usr/local/bin/paraview

  Replace /[user-specific-path/ParaView-5.x.x]/ with the path where ParaView got installed. For instance, in MacOS the full path looks like this: /Applications/ParaView-5.12.0.app/Contents/MacOS/paraview

If you were successfull, typing the following in the terminal will launch the ParaView:

paraview

To test that ParaView is correctly installed, run one of the examples of the GeometricTools package as follows (copy/paste this in the Julia REPL):

# Install GeometricTools
import Pkg; Pkg.add("GeometricTools")

import GeometricTools as gt

# Load example
examplepath = joinpath(dirname(pathof(gt)), "..", "examples", "example_simple.jl")
include(examplepath)

# Run example: it will pull up paraview with a good-looking cube
simple_box2()

ParaView will then pull up with a rendering of a cube (click the Apply button under Properties to make it visible).

(Optional) OpenVSP

FLOWUnsteady can import geometry created in OpenVSP using VSPGeom.jl. We recommend installing OpenVSP in your system, then adding VSPGeom.jl to Julia:

] add VSPGeom

PyCall

One of the dependencies (AirfoilPrep.jl) is a wrapper of Python code that is written in Python v3.8+. For this reason, make sure that your Python version linked to PyCall is 3.8 or higher. You can do that as follows:

# Install PyCall
import Pkg; Pkg.add("PyCall")

# Point environment to your Python 3.8 (or higher)
ENV["PYTHON"] = "path/to/your/python3"

# Rebuild PyCall
Pkg.build("PyCall")

Then close and reopen the Julia REPL, and run:

import PyCall
PyCall.pyversion

which should reveal your Python version:

v"3.8"

Since PyCall now relies on a custom install of Python3, make sure that:

• matplotlib, mpmath, and scipy are installed in that Python,

  pip3 install matplotlib mpmath scipy --user

• For optimal experience, verify that matplotlib uses the Qt5Agg backend. Useful instructions can be found here and here.

If you run into errors with PyPlot while running FLOWUnsteady, they are likely related to one of those two items.

Add FLOWUnsteady

You are now ready to install the FLOWUnsteady package.

In the julia REPL:

url = "https://github.com/byuflowlab/"
packages = [ "AirfoilPrep.jl", "FLOWVLM", "FLOWNoise", "BPM.jl", "FLOWVPM.jl", "FLOWUnsteady"]
Pkg.add([ Pkg.PackageSpec(; url=url*name) for name in packages ])

Test FLOWUnsteady

In order to test that FLOWUnsteady and all dependencies were successfully installed, try running some of the examples under FLOWUnsteady/examples/.

For instance, you can run the Simple Wing example as follows:

import FLOWUnsteady as uns

include(joinpath(uns.examples_path, "wing", "wing.jl"))

or you can run the Tethered Wing example:

import FLOWUnsteady as uns

include(joinpath(uns.examples_path, "tetheredwing.jl"))

This will pull up Paraview visualizing the simulation. Kick off your shoes, sit back, and enjoy the simulation that you have just run.