1. 30 Oct, 2015 3 commits
  2. 29 Oct, 2015 6 commits
  3. 27 Oct, 2015 4 commits
  4. 26 Oct, 2015 5 commits
  5. 25 Oct, 2015 5 commits
  6. 24 Oct, 2015 1 commit
  7. 23 Oct, 2015 3 commits
  8. 22 Oct, 2015 4 commits
  9. 21 Oct, 2015 2 commits
  10. 19 Oct, 2015 3 commits
    • Henry Weller's avatar
    • Henry Weller's avatar
      sixDoFSolver: Run-time selectable solver (integrator) for sixDoFRigidBodyMotion · f4202d9e
      Henry Weller authored
      The built-in explicit symplectic integrator has been replaced by a
      general framework supporting run-time selectable integrators.  Currently
      the explicit symplectic, implicit Crank-Nicolson and implicit Newmark
      methods are provided, all of which are 2nd-order in time:
      
      Symplectic 2nd-order explicit time-integrator for 6DoF solid-body motion:
      
          Reference:
              Dullweber, A., Leimkuhler, B., & McLachlan, R. (1997).
              Symplectic splitting methods for rigid body molecular dynamics.
              The Journal of chemical physics, 107(15), 5840-5851.
      
          Can only be used for explicit integration of the motion of the body,
          i.e. may only be called once per time-step, no outer-correctors may be
          applied.  For implicit integration with outer-correctors choose either
          CrankNicolson or Newmark schemes.
      
          Example specification in dynamicMeshDict:
          solver
          {
              type    symplectic;
          }
      
      Newmark 2nd-order time-integrator for 6DoF solid-body motion:
      
          Reference:
              Newmark, N. M. (1959).
              A method of computation for structural dynamics.
              Journal of the Engineering Mechanics Division, 85(3), 67-94.
      
          Example specification in dynamicMeshDict:
          solver
          {
              type    Newmark;
              gamma   0.5;    // Velocity integration coefficient
              beta    0.25;   // Position integration coefficient
          }
      
      Crank-Nicolson 2nd-order time-integrator for 6DoF solid-body motion:
      
          The off-centering coefficients for acceleration (velocity integration) and
          velocity (position/orientation integration) may be specified but default
          values of 0.5 for each are used if they are not specified.  With the default
          off-centering this scheme is equivalent to the Newmark scheme with default
          coefficients.
      
          Example specification in dynamicMeshDict:
          solver
          {
              type    CrankNicolson;
              aoc     0.5;    // Acceleration off-centering coefficient
              voc     0.5;    // Velocity off-centering coefficient
          }
      
      Both the Newmark and Crank-Nicolson are proving more robust and reliable
      than the symplectic method for solving complex coupled problems and the
      tutorial cases have been updated to utilize this.
      
      In this new framework it would be straight forward to add other methods
      should the need arise.
      
      Henry G. Weller
      CFD Direct
      f4202d9e
    • Henry Weller's avatar
      reactingTwoPhaseEulerFoam: Remove the build-in write of Ur · 11f35cc7
      Henry Weller authored
      Ur can be generated using a functionObject or in the post-processor
      11f35cc7
  11. 17 Oct, 2015 3 commits
  12. 15 Oct, 2015 1 commit