LNS3D is part of the Flow Physics & Simulation code suite of fluid mechanics analysis codes to explore linear and nonlinear phenomena, primarily for compressible flows..
The main LNS3D web-site describes the
overall capability and there are numerous README.md files (including
this one) that describe specific capabilities, codes, and test cases.
LNS3D solves the compressible Navier-Stokes equations with 3-components (u,v,w) and 2.5 dimensions (x,y,z) were the solution must be a single Fourier mode.
LNS3d uses a fourth-order finite-difference method and is generally designed to resolve highly sensitive flow phenomena such as aero-acoustics, receptivity and linear instability.
LNS3D can also solve both linear and nonlinear 2.5d-3c problems depending on the problem setup but the code is specifically designed to solve for perturbations on a baseflow to increase the fidelity of the solution.
To build you need to link (and possibly edit) the most appropriate *.mak
file. For example, using GCC Gfortran on Mac OS X (Darwin), one would use
cd src
ln -s gcc.mak Makefile
And then
make clean && make
The executable is lns3d.
The following tables describes the supporting tools for lns3d that are
required for complete end-to-end workflows and analysis.
| Directory | Description |
|---|---|
src |
Primary source for lns3d flow solver |
ssd |
Original Cray SSD enabled source for lns3d flow solver |
nossd |
Original Cray version of lns3d flow solver with SSD disabled |
pre |
Preprocessor that makes consistent metrics from a grid file |
util |
Various utilities for preparing and analyzing lns3d runs |
mesh |
Mesh generators for specific types of geometries |
test |
Simple tests and examples of lns3d and tools |
docs |
Documentation information |
Each of these tool directories contains a separate README file that
describes how to build and use them.
Finally, the test directory contines several examples demonstrating
workflows and capabilities of lns3d that can both help assess that
your build are working correctly and show new users how to setup and
run problems.
Compressible vortex rebound from a solid wall
S. Scott Collis
flow.physics.simulation@gmail.com