LB3D Documentation

Welcome to LB3D, a Lattice-Boltzmann simulation application! This is the provisional start page of its manual – heavily WIP, but on its trajectory to helping users to operate LB3D, and developers to understand its internals.

How do I set up LB simulations? What does LB3D internally? Why have certain design decisions been made in that way? What are the scientific sources that motivate models? Throughout several periods¹ of optimism and scientific/programming best practice, a substantial amount of this kind of background knowledge has been added to the code and/or an accompanying stand-alone handbook². Since April 2022, we have put quite some effort to convert the existing bits into a shape that is digestible by FORD, to be processed into this nifty hypertext site.

Ongoing efforts

• A good part of the old manual goes on existing in form of the parts directory. We are moving descriptions and explanations into the source files, while we somehow™ maintain a browseable shape of the handbook.
• We are aiming to convert the parts pages into short-ish (about 1 page) introductory pages that explain the scope of the part, link to the input parameters/namelists, most important modules, tests and examples.
• Of particular importance is the old namelist description page, that is known to consist of invaluable information but with 100% outdated context
• Automated namelist gathering for quick reference of input file options
• Useful examples, quick-start guide
• Continuous Deployment of this documentation through the GitLab CI pipelines
• (Low priority) Trivia about the code structure, like how source code file lengths across the repository follow the log-normal distribution, or the rewrite effort of the last years has reduced the lines of code by a factor surprisingly close to $1:\sqrt{2}$ (from 80902 to 57154), while maintaining/extending functionality and performance.
• ...whatever you think should be part of a user manual