Restart and geometrical files - gnomeCreative/HYBIRD GitHub Wiki

logo

Particle/Object restart file

Every run with DEM activated requires the provision of two extra restart files: the particle restart file and the object restart file. Both have the same format, which is:

NP index_0 size_0 r_0 px_0 py_0 pz_0 ux_0 uy_0 uz_0 wx_0 wy_0 wz_0 q0_0 q1_0 q2_0 q3_0 qp0_0 qp1_0 qp2_0 qp3_0 index_1 size_1 r_1 px_1 py_1 pz_1 ux_1 uy_1 uz_1 wx_1 wy_1 wz_1 q0_1 q1_1 q2_1 q3_1 qp0_1 qp1_1 qp2_1 qp3_1 ... index_NP size_NP r_NP px_NP py_NP pz_NP ux_NP uy_NP uz_NP wx_NP wy_NP wz_NP q0_NP q1_NP q2_NP q3_NP qp0_NP qp1_NP qp2_NP qp3_NP

Here, NP is the total number of particles and is written in the first line. What follows is a sequence of lines, one for each particle, describing the state of motion and the geometrical characteristics of that particle.

  • index: This is a sequential integer, growing from 0 to NP​.
  • size: In this version, has to be 1 (spherical particle).
  • r: The radius of the particle.
  • px py pz: The particle initial position.
  • ux uy uz: The particle initial velocity.
  • wx wy wz: The particle initial rotational velocity.
  • q0 q1 q2 q3: The particle initial orientation, expressed in quaternions. When unknown, the values (1 0 0 0) are sufficient.
  • qp0 qp1 qp2 qp3: The particle initial rotational speed, expressed in quaternion rates. When unknown, the values (0 0 0 0) are sufficient.

In case this file is used to generate objects (immobile particles), all velocities and rotational velocities entries are ignored by the code.

Fluid restart file

Currently missing...