Example AMR Aeronautics Dataset:  exajet-d12

Acknowledgements:

Thanks to Dassault Systèmes (https://www.3ds.com/) for allowing
this dataset to be used for research purposes.  Please acknowledge
their generosity in your work.


Introduction:

In this directory is a "semi-span" (i.e., half an airplane, split
on the symmetry plane) model of a large civilian transport aircraft.
The mesh is a type of adaptive mesh refinement (AMR), somewhat like a
an octree, but without a single root node.  This is sometimes referred
to as a "forest of octrees".  The solution was produced by Exa's
PowerFLOW solver.  There are 656444884 cubic hexahedra in this
dataset.  The data are "cell centered," i.e., the data are per
hexahedron.

This type of mesh format is also used by other CFD solvers, such
as NASA's Cart3D.

# r_min: 3
# r_max: 6
# bbi: ((1232128, 1259072, 1238336), (1270848, 1277952, 1255296))
# bbr: ((-1.73575, -9.44, -3.73281), (17.6243, 0, 4.74719))
# i_to_r_scaling: (0.0005, 0.0005, 0.0005)
# r_to_i_scaling: (2000, 2000, 2000)
# smallest_cell_size: (0.004, 0.004, 0.004)
# card(H): 656444884


The Files:

hexas.bin:
This is a binary file, with 4 4-byte integers (little endian) per
cubic hexahedron.  The integers are in an array-of-structs layout:
4 contiguous integers specify a hexahedron.  The coordinates are in
integer.  The first three integers specify the low-corner of the
hexahedron, the fourth integer specifies the refinement level, r.  The
size of the hexahedron is based on the refinment level, 1 << r.  The
refinement levels range from 3 to 6.  Refinement level 3 would be the
finest, with hexahedra that have a side length of 8.

hexa-types.bin:
This is a binary file, 1 byte per hexahedron.  Full hexahedra
(i.e., not intersected by model surfaces) are assigned type 0,
cut hexahedra are assigned 1.

surfaces:
This directory contains the aircraft surfaces, one file per CAD
object, in binary legacy vtk format.  There are 151 surfaces.

density/*-density.bin:
x_velocity/*-x_velocity.bin:
y_velocity/*-y_velocity.bin:
z_velocity/*-z_velocity.bin:
Solution files, binary, little-endian, with 1 float per hexahedron,
423 time steps.


Publications:

I. Wald, S. Zellmann, W. Usher, N. Morrical, U. Lang, V. Pascucci.
Ray Tracing Structured AMR Data Using ExaBricks.  IEEE Transactions
on Visualization and Computer Graphics, 27(2), Feb. 2021.