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How to determine when a Particle hit/touch a boundary in Particle Tracing Module

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I am trying to model particle trajectory using Particle Tracing for Fluid Flow module of COMSOL 4.4. I am using Dielectrophoresis and Electric force. When the particle touch an electrode, I would like to give some charge to it. But I don't know how to find the precise moment when the particle hit the solid electrode. I have tried particle position but its not accurate. I would like to know how do I determine the precise moment when a particle hit or touch a specific boundary? Could anyone please help me with this?

2 Replies Last Post 11.09.2014, 17:04 GMT-4
Daniel Smith COMSOL Employee

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Posted: 10 years ago 09.09.2014, 17:21 GMT-4
Hi, you need to check the "Store particle status data" checkbox in the Particle Tracing for Fluid Flow properties. After solving, a new variable is created which is equal to the time at which the particle stopped. You can find this in the postprocessing menu Particle Tracing for Fluid Flow>Particle statistics. It should be called, for example, fpt.st.

This will only be available for particles whose Wall condition was set to Freeze or Stick.

Dan
Hi, you need to check the "Store particle status data" checkbox in the Particle Tracing for Fluid Flow properties. After solving, a new variable is created which is equal to the time at which the particle stopped. You can find this in the postprocessing menu Particle Tracing for Fluid Flow>Particle statistics. It should be called, for example, fpt.st. This will only be available for particles whose Wall condition was set to Freeze or Stick. Dan

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Posted: 10 years ago 11.09.2014, 17:04 GMT-4
Thank you very much Dan. I wanted to access to the data during every iteration while the simulation is running. I am calculating distance of the particle from the electrode center instead. Could I please ask one more question? My electrodes are spherical and material is copper. The particles are in fluid. Is the particle going to stop because of solid electrode? The particles are gathering on the top of each other. How can I stop them when they touch each others outer surface? Could I please send you my model?
Thank you once again for your kind help.
Thank you very much Dan. I wanted to access to the data during every iteration while the simulation is running. I am calculating distance of the particle from the electrode center instead. Could I please ask one more question? My electrodes are spherical and material is copper. The particles are in fluid. Is the particle going to stop because of solid electrode? The particles are gathering on the top of each other. How can I stop them when they touch each others outer surface? Could I please send you my model? Thank you once again for your kind help.

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