Monitoring and Troubleshooting Particle Feed
Altair EmployeeIn many Barracuda simulations there is a particle feed of some kind. Most commonly this will be at a Flow or Injection BC. It is important to monitor a particle feed to ensure that it is meeting the expected flow rate. A few things are important to be able to monitor feed flow rates:
- Specify a Flux plane name for all boundary conditions. If you leave the Name blank, no flux plane data will be available for the BC.
- Use a transient flow file to control the fluid and particle feed flow rates. This will allow you to adjust flow rates if needed while the simulation is running.
Create an XY plot in Tecplot using the data from the boundary flux plane, specifically the “Particle mass flow rate of all species (5 time step average)” column versus time. This will show the actual particle flow rate at the BC, which you can compare to the desired flow rate input.
It is possible the feed rate will not match the expected flow rate, and the solver will output a message like this to the terminal and history.log:
This could be due to a number of factors. The most common reasons are:
- Trying to feed into cell(s) with a high volume fraction
- Not enough fluid being introduced with the particle feed
- Not enough resolution (Number Density Manual) of the feed
In order to feed the desired flow rate, a few options can be tried:
- Changing the feed location out of a high volume fraction section of the system
- Increasing the fluid flow rate to bring the feed in at a lower volume fraction
- Increasing the resolution of the feed by increasing the Number Density Manual
The first option would necessitate a complete restart at time equal zero, but the second and third options can be iteratively changed while a simulation is running through the use of transient flow files.