Hi,
I've built a COMSOL model that models the joule heating of electrodes that are designed to heat up channels in a microfluidic device. I am able to choose a V0 (input voltage) run a transient study and get back temp values very close to what I expect so I think my model is sound.
What I want to do now is vary the voltage applied over time. Lets say some type of square function that applies 5V for 2 second 2V for 2 sec and see how that will affect the heat in my system over time. When I try using the function: V0 = 5V*(sin(2*pi*t/4)>0) + 2V*(sin(2*pi*t/4)<=0) to define the input voltage my model does not solve giving me the following error: "Repeated error test failures. May have reached singularity at time: 0. Last time step is not converged." I tried this first because I have used this technique before with a boundary temperature source to apply a varying temperature.
This is obviously not the best way to vary the voltage within the model. Is there a better way to do this? Would it be some kind of periodic condition set on the boundary heat source? I am new to COMSOL so detailed explanations would be greatly appreciated.
Thanks
I've built a COMSOL model that models the joule heating of electrodes that are designed to heat up channels in a microfluidic device. I am able to choose a V0 (input voltage) run a transient study and get back temp values very close to what I expect so I think my model is sound.
What I want to do now is vary the voltage applied over time. Lets say some type of square function that applies 5V for 2 second 2V for 2 sec and see how that will affect the heat in my system over time. When I try using the function: V0 = 5V*(sin(2*pi*t/4)>0) + 2V*(sin(2*pi*t/4)<=0) to define the input voltage my model does not solve giving me the following error: "Repeated error test failures. May have reached singularity at time: 0. Last time step is not converged." I tried this first because I have used this technique before with a boundary temperature source to apply a varying temperature.
This is obviously not the best way to vary the voltage within the model. Is there a better way to do this? Would it be some kind of periodic condition set on the boundary heat source? I am new to COMSOL so detailed explanations would be greatly appreciated.
Thanks