===== 2-D Fortran CFD code for tornado-like vortices =====

The source code is here: [[https://github.com/bfiedler/ezan | at github]]

The **eza** in the name is for //easy axisymmetric//. Perhaps **n** is //new// and **3** is version?
I believe this code is what I used as the companion axisymmetric code in {{ :tornadobox:suction_vortices_and_spiral_breakdown_in_numerical.pdf | my 2009 QJ article}}.
It produces slightly difference results than the code for [[https://12characters.net/anim2dvort/ | axisymmetric simulations prior to 2009]], mainly because the viscosity profile was simplified for compatibility with the  [[tornadobox|3-D Fortran CFD code for tornado-like vortices]]. Browse the code at my [[https://12characters.net/ezan3browser/ | ezan3 Browser]].

<code>
wget https://github.com/bfiedler/ezan/blob/main/ezan3_2025.tar.gz
gunzip ezan3_2025.tar.gz
tar xvf ezan3_2025.tar
cd ezan3_2025
./Runall
</code>
This will require about 15 minutes of wall clock on an ancient PC with an i7 chip.


Make a browser with:
<code>
f90tohtml ezan3.f2h
</code>


==== Domain and grid ====

^{{ :ezan:wholedomain.png?direct |}}^
|The r-z plane of the cylindrical domain. The perpetual buoyancy the drives the flow is contoured. The stretched grid is shown.|

==== Time history of extremes ====
{{ ::ezan:nosliphist.png?direct |}}
==== Animation of entire time ====

{{url>https://12characters.net/noslip.html  98%,650}}

==== Zoom in time and space ====

Note the change in contour intervals, so the extremes can be detected.

{{url>https://12characters.net/intense.html  98%,650}}