Recording Calculation Results

You can run a DEM calculation and record the results for later analysis and reporting. Recording doesn't need to capture every calculation step, only a subset – e.g. a setting of 60 frames per second (fps) records 60 steps per second for playback, even at a Critical Time Step dt of 0.005 s (1/0.005 = 200 calculation steps per second). These recordings capture the position and velocity of every individual particle and can be used to estimate belt/chute wear rates, impact energy and more. You can also record a video – see Record a Video (MP4).

A very high fps setting means many more time steps have to be recorded, using more memory, CPU time and disk space.

To record a calculation

1. Build your transfer chute model and enter all required design data.
2. Run a trial calculation at a low feed rate (e.g. 50–100 tph) to check the model and finish fine-tuning.
3. If the calculation is running, press Stop Calculation.
4. Press Record Calc (it changes to Stop Recording Calc while active).
5. Press Calculate to run the DEM calculation for the trial run – use Stop Calculation / Calculate to pause and resume as needed.
6. After the calculation has run for a while, press Stop Calculation.
7. Go to the Recording tabsheet, which shows two tables – recorded time steps in the upper table, and the per-particle data for the selected time step in the lower table.

Click a row in the upper table to redraw the chute with particles at the positions recorded for that time step (once you do, the calculation can no longer be resumed – it must be restarted from scratch). Use the down arrow key to step through subsequent time steps. Clicking a row in the lower table highlights that particle in bright orange-red in the drawing.

Right-click a row in the lower table for a context menu: Draw Trace this Particle, View Report - all Particles and View Report - this Particle. See Trace a Single Particle and Calculation Reports.

Review particle velocity to confirm it reaches the correct belt speed before the discharge point – you may need a longer belt run-up so particles have enough contact time to reach speed.

Saving and deleting a recording

Use the Save/Open buttons on the toolbar above the drawing to save the recorded data as an XML file (openable in Excel or any text/XML tool) or reload a previously saved one. To delete a recording, right-click the upper table on the Recording tabsheet and choose the delete option – there is no undo, so be sure before discarding data.