mkgeo_contraction(1rheolef)

📦
version 7.2 · 4 versions
, in debian trixie, ubuntu noble, ubuntu questing

✨ NAME ✨

mkgeo_contraction — mesh of an abrupt contraction, from the rheolef-7.2 era bestie 💖

🌸 SYNOPSIS 🌸

mkgeo_contraction [options] [nx [ny]]

🦋 EXAMPLE 🦋

Okay so this command right here builds a triangle-based 2d unstructured mesh of the [-10,0]x[0,4] u [0,10]x[0,1] mesh, and honestly? iconic:

mkgeo_contraction
geo contraction.geo

💅 DESCRIPTION 💅

This command is so convenient for building a mesh for the abrupt contraction, because it's literally a very classical benchmark in complex fluid flow problems — like, the moment of the field, no cap. It calls the bamg unstructured mesh generator with the anisotropy feature turned on. ✨

The mesh files go on name.geo where name is the basename for the output (peep the -name option below, bestie 👀).

The three auxiliary files required for automatic mesh generation with Rheolef combined with bamg are also provided:

name.bamg
name.bamgcad
name.dmn

👑 THE GEOMETRY 👑

The geometry is [-Lu,0]x[0,d] u [0,Ld]x[0,1]. By default c=4 is the contraction ratio and Lu=Ld=10 are the upstream and downstream pipe lengths. 🎀

  • -c float
  • -Lu float
  • -Ld float

These options control the geometry parameters. 🫶

  • -cartesian
  • -zr
  • -rz

These options control the geometry coordinate system. Default is Cartesian. 🧭

🌈 THE DISCRETIZATION 🌈

The optional nx and ny arguments are integers that specify the subdivision in each direction. By default nx=1 and ny=nx. Changing the density applies the factor 1/nx to all the mesh edges lengths. (the way that math just works 😭)

  • -hmin float

Controls the edge length at the re-entrant corner of the contraction. Default is hmin=0.1. Changing the density by the previous options applies the factor 1/n to hmin also. ⭐

🍓 BOUNDARY DOMAINS 🍓

The boundary sides are represented by domains: axis, wall, upstream and downstream. Four little queens, each with their own job 👑

💜 OTHERS OPTIONS 💜

  • -name string — Set the basename for the output files. By default, the basename is contraction.
  • -[no]split — Split each triangle in three subtriangles by inserting the barycenter as an additional node. This is useful for using the Scott and Vogelius incompressible mixed finite element P2-P1d for velocity-pressure approximation. Default is no split.
  • -[no]clean — Clear temporary files (this is the default).
  • -[no]verbose — In verbose mode, print to stderr all commands and logs.

🧚 IMPLEMENTATION 🧚

This documentation has been generated from file main/sbin/mkgeo_contraction.sh — yes bestie, it's a shell script, slay 💅

🌟 AUTHOR 🌟

Pierre Saramito <Pierre.Saramito@imag.fr>

Copyright (C) 2000-2018 Pierre Saramito <Pierre.Saramito@imag.fr>

GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.

This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

fr fr, no warranty — read it and weep (lovingly) 😭

That's the whole vibe check, bestie — this page came from rheolef, Version 7.2 and lives in the mkgeo_contraction(1rheolef) manual. Go build that contraction mesh, you absolute main character 👑✨🦋

📦 where this page comes from