This repository contains the STL files and OpenFOAM control files that were used for the reverse sprinkler simulations in https://zmatt.net/reverse-sprinkler-part-3/

Basic usage:

1. Ensure OpenFOAM is installed and in the path, e.g. source /usr/lib/openfoam/openfoam/etc/bashrc. I used ESI OpenFOAM v2406.
2. Run make at top level to generate meshes for all designs, or run make within a specific geometry directory (e.g. designA/geometry) to generate a mesh for that design.
3. Run make within a case directory (e.g. designA/steady-100) to run a simulation.
4. Open the case.foam file in Paraview for analysis.

By design, most files within the case directories are symlinks, for example constant/turbulenceProperties is a symlink to one of the shared/constant/turbulenceProperties.* files, this symlink can be modified to change the turbulence model. In the committed cases, the steady-100 cases use a laminar model (no turbulence). The transient-initial-500 case uses k-omega SST to generate sane initial conditions for transient simulation, and transient-500 then uses k-omega SST DDES (delayed detached eddy simulation) for the actual transient simulation.

The flows are set up to be pressure-driven, with the outlet pressure derived from the target Reynolds number supplied in the params file in each case directory. A correction factor in that file that can be altered to converge on the required flow rate.

The five designs were drawn in Onshape:

• Design A: https://cad.onshape.com/documents/972924324f4b7380846c87b2/w/6c4e2cad260d9f3a81e4cdc8/e/9496ec194a56dd089c194d95
• Design B: https://cad.onshape.com/documents/1c32e01ef3334e96db67690f/w/2f56350e479405532855a46c/e/25c703ed53f84895258d062d
• Design C: https://cad.onshape.com/documents/76bea673445c12913a4942aa/w/6f5ab22ad81d5b2a8070925a/e/2b83b078a7259e26230dcdae
• Design D: https://cad.onshape.com/documents/41ca4284c9e610edeb9c9b57/w/8b90f2b45bcf01023b8d1a21/e/54e3ed552f9c54115abde596
• Design E: https://cad.onshape.com/documents/a61ee421ada3f753aac550c2/w/af063cb77ddebd99e7d94d72/e/db29fed9c6e26245a56661d8

If modifying the designs, export to STL, ensuring that STL Format is set to Text and "Export unique parts as individual files" is checked. Then extract the resulting zip file and run the two parts through util/mergeSTL.py to generate designX/constant/triSurface/geometry.stl.