DEMPhysics

This module adds centrifugal force and location-specific application of centrifugal and gravitational forces to LIGGGHTS-PFM This code is developed for the scientific article linked.

Contributing Authors:

• MSc. Damla Serper (Aalto Univeristy, Finland) 'corresponding author'
• Dr. Kevin Hanley (University of Edinburgh, UK)

How to use the code:

• Clone this directory into the LIGGGHTS-PFM src directory on your local computer.

• Here you can use the provided .gitignore file to only stage the required files within your folder.

• Copy and move fix_centrifugal.cpp, fix_centrifugal.h, fix_gravity.cpp and fix_gravity.h files from DEMPhysics folder to upper src directory, replacing the original LIGGGHTS-PFM versions.

• Recompile the LIGGGHTS-PFM.

• Here are some examples of how to add the centrifugal force and modified gravitational force within LIGGGHTS-PFM .in script:

  You are intending to use centrifugal force (keyword: centrifugal, 4 arguments)

  • Here the case is set for a submerging, stationary, cylindircal inlet pipe within a rotating centrifuge inner basket. We want to activate the centrifugal force only within the inner basket plus particle radius and outside of the inlet pipe.
  • param[0] = rotational speed
  • param[1] = radius of the inlet pipe
  • param[2] = lower y coordinate of the inlet pipe
  • param[3] = radius of the inner basket of the centrifuge
  • Example syntax: fix cent_fix all centrifugal 157.0796 0.017 -0.0033 0.069

  You are inteding to use modified gravitational force (keyword: gravity, 5 arguments)

  - Here the case is set for a submerging, stationary, cylindircal inlet pipe within a rotating centrifuge inner basket. We want to activate the gravitational force only within the inner basket plus particle radius and outside of the inlet pipe, since the inlet pipe has a set flow rate we want to keep.
  

  • param[0] = radius of the inlet pipe
  • param[1] = lower y coordinate of the inlet pipe
  • param[2] = x vector direction to apply the acceleration
  • param[3] = y vector direction to apply the acceleration
  • param[4] = z vector direction to apply the acceleration
  • Example syntax: fix grav_fix all gravity 9.81 vector 0.017 -0.0033 0 -1 0

• NOTE: Currently the rotation is assumed to be along y axis. Please refer to image below for understanding the set-up: