EDEM Simulator - Run the Simulation

Once you have set up the model, learn how to run fast and efficient simulations using EDEM Simulator.

To run the simulation:
Click the icon on the toolbar to open EDEM Simulator.

Set the Time options

The first step in running the simulation is to set the Time Step. The Time Step is the amount of time between iterations (calculations). The Time Step value is displayed as both the actual Time Step (in seconds) and as a percentage of the Rayleigh Time Step.

To set the Time Step:
  1. In this simulation, ensure that the Auto Time Step checkbox is cleared.
  2. Set the Fixed Time Step to 5e-6s.
  3. Set the simulation time and data write-out frequency.
    The simulation time is the amount of real time your simulation represents.
    1. In the Simulation Time section, set the Total Time to 5 s.
    2. Set the Target Save Interval to 0.1 s to specify the write-out frequency.
      Note: It is not always necessary to write a data point for every iteration in a simulation. Doing so will usually result in a slow simulation and a large amount of data being collected.
    Note: The Rayleigh Time Step is the time taken for a shear wave to propagate through a solid particle. When using a simulation with a range of particle sizes, the Rayleigh time step is calculated based on the smallest particle size, according to the following equation:

    Δt= πR ρ G 0.1631v+0.8766 MathType@MTEF@5@5@+= feaahGart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeuiLdqKaam iDaiabg2da9maalaaabaGaeqiWdaNaamOuamaakaaabaWaaSaaaeaa cqaHbpGCaeaacaWGhbaaaaWcbeaaaOqaaiaaicdacaGGUaGaaGymai aaiAdacaaIZaGaaGymaiaadAhacqGHRaWkcaaIWaGaaiOlaiaaiIda caaI3aGaaGOnaiaaiAdaaaaaaa@496C@

    where R, ρ, G and ν are the radius, density, Shear modulus, and Poisson’s ratio of the smallest particle respectively. When using the Tavares UFRJ Breakage model, it is recommended to set the Time Step between 1-5% of the calculated Rayleigh Time Step in order to accurately calculate the particle forces and resultant breakage particle size distribution.

Set the Solver Engine and Grid options

The next step in running the simulation is to set the grid options that can be used to optimize the simulation.

To set the solver engine and grid options:
  1. Select CPU Solver or GPU Solver engine.
    The GPU will typically be faster (often 10x or greater, depending on the GPU type). However, not all computers will have a valid GPU card.
    1. If GPU Solver is to be used, select GPU CUDA Solver in the Simulator Engine section.
    2. Click Advanced Settings and set Solver Precision to Hybrid to obtain the optimal speed vs accuracy calculation.
  2. Set the grid options.
    The grid options are used to optimize the simulation if you are using the CPU solver. Depending on the application and the minimum size you are trying to achieve, the following options are available:
    1. Simulator Grid Option 1

      Select the Auto Grid Resizing checkbox.

      EDEM will evaluate the grid dynamically based on the current sizes in the system, and will provide the optimum grid. This is useful for an application like Breakage where the size distribution is changing due to which the optimal grid setting is also changing during the simulation.

    2. Simulator Grid Option 2

      Click Estimate Cell Size to to obtain an estimate of the optimal grid setting. After running the simulation for some time, stop the simulation and check whether you have produced the smallest fragment, and click Estimate Cell Size again. EDEM will calculate the cell size in the most optimized way considering the smallest particle. The more grid cells a simulation uses, the more system RAM is required. It is recommended to find a balance between RAM usage and simulation performance.

Run the Simulation

The last step is to run the simulation.

To run the simulation:
  1. Click the Start Progress icon in the Simulation window.
  2. In the Viewer Controls, click the Refresh Viewer icon or the enable Auto Update icon at any point to update the Viewer and view the progress of the simulation.
Next Step - Analyze your Results