Conditional Release of DPM Particles in Fluent - UDF
 

Hi,
I am trying to implement a DPM model where i want to have an option to release the DPM particles from my source face based on a predefined condition. I would love to hear some ideas as to how to go about solving this problem. Below is an example of what i want to do.

Step 1: Initialize DPM model
Step 2: Define injections and the injection location - in this case, a "wall" in my model
Step 3: Calculate Turbulent Dissipation Rate (TDR) on each face on the wall of interest.

=====this is where i need ideas/help======
Step 4: Do a conditional release of particles per the following ..
if TDR > x ---> release the particles from the surface.
if TDR < x ---> DO NOT release the particles from the surface.
==================================

Step 5: After time = t sec, count the number of particles still on the surface of the wall and do a calculation of the % of particles that are still adhered to the surface due to the lack of appropriate TDR that is required to dislodge the particles from the surface..

I need help with STEP 4 only.
how can one implement a conditional release of the particles and let the particles stay on the surface if the condition is not satisfied.

i looked at the define dpm body force udf example in the udf manual, which tells you how to assign a magnetic force term to a cell but doesnt really answer my question about the release.

thanks in advance for any comments/ideas/help.

Suresh Nulu.