#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     | Website:  https://openfoam.org
#   \\  /    A nd           | Copyright (C) 2024-2025 OpenFOAM Foundation
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM.
#
#     OpenFOAM is free software: you can redistribute it and/or modify it
#     under the terms of the GNU General Public License as published by
#     the Free Software Foundation, either version 3 of the License, or
#     (at your option) any later version.
#
#     OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
#     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
#     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
#     for more details.
#
#     You should have received a copy of the GNU General Public License
#     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
#
# Script
#     frictionFactorReGraph
#
# Description
#     Plots a graph of "frictionFactor" vs "Re" for the moodyChart tutorial
#
#------------------------------------------------------------------------------

! command -v gnuplot >/dev/null 2>&1 && \
    echo 'gnuplot not found - skipping graph creation' && \
    exit 1

# Formatting
format () {
    cat<<EOF
set term pngcairo size 750,500
set key right top
set notitle
set xlabel "Reynolds number, Re (-)"
set ylabel "Friction coefficient, f_{D} (-)"
set xrange [100:1e8]
set xtics (1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8)
set format x "10^{%L}"
set yrange [0.005:0.4]
set ytics (0.005, 0.01, 0.02, 0.04, 0.08, 0.16, 0.32)
set logscale xy
EOF
}

ptFmt='lt 1 lw 2 ps 2'
lineFmt='lt 1 lw 1.5'
colLam='lc rgb "dark-spring-green"'
colTurb='lc rgb "dark-magenta"'

# Plotting
gnuplot<<EOF
    $(format)
    Ks = 0
    D = 0.1
    f(x) = x > 2000 ? 1/(-1.8*log10((Ks/D/3.7)**1.11+(6.9/x)))**2 : 0
    g(x) = x < 2000 ? 64/x : 0
    set output 'moodyChart.png'
    plot 'postProcessing/0/frictionFactor/data' u 2:3 t 'Laminar CFD' $ptFmt $colLam, \
         'postProcessing/2/frictionFactor/data' u 2:3 t 'RAS CFD' $ptFmt $colTurb, \
          g(x) t 'Laminar (64/x)' $lineFmt $colLam, \
          f(x) t 'Turbulent (Haaland)' $lineFmt $colTurb
EOF