I am using the 4.3 version to calculate the Brownian forces on a 2D geometry. My model looks pretty much like the "Brownian Motion" model from the Comsol's Model Library. The solver converges and I can visualize the particles dynamics.
The problem is that I cannot numerically evaluate the Brownian forces values. For example, I tried using the Surface Average option from the Derived Values Menu, and I got the attached error message.
It happens the same when I am trying to calculate the values for the forces using the "Brownian Motion" model from the Model Library. I also saw that there is no specific option, after solving the problem, when trying to evaluate the Brownian Forces: I wasn't able to find a clear option for the Brownian forces as it can be found in the Results area for e.g. Drag Forces (more details in the attached image).
Is there any specific way to calculate the Brownian force that acts upon a particle or, more important, upon all the particles in the computational domain?
The problem is that I cannot numerically evaluate the Brownian forces values. For example, I tried using the Surface Average option from the Derived Values Menu, and I got the attached error message.
It happens the same when I am trying to calculate the values for the forces using the "Brownian Motion" model from the Model Library. I also saw that there is no specific option, after solving the problem, when trying to evaluate the Brownian Forces: I wasn't able to find a clear option for the Brownian forces as it can be found in the Results area for e.g. Drag Forces (more details in the attached image).
Is there any specific way to calculate the Brownian force that acts upon a particle or, more important, upon all the particles in the computational domain?