Please find attached a micromixer Comsol tutorial. For a first look, you can neglect the particle tracing aspects. I hope it will be of use and I also hope that this is not the same tutorial as the one recommended by Shrish Shukla.
For a more convenient approach, I would suggest you to study the 2D model of your magnetic stirrer first (geometry comprised of a circle with an ellipse in the center). After this simpler model is fully functional, you can easily create and solve the 3D model too.
It can be done by just placing a desire rpm of rotating and explaining the way of placing a stirring function and how to add that physic in particular case over here is bit hard so instead of explaining over here i am sending you a similar tutorial in which you can find this details and i would like to suggest you that first follow step of tutorials and try some other tutorials which are available then after you ill able to resolve your problem yourself.
Please find attached a micromixer Comsol tutorial. For a first look, you can neglect the particle tracing aspects. I hope it will be of use and I also hope that this is not the same tutorial as the one recommended by Shrish Shukla.
For a more convenient approach, I would suggest you to study the 2D model of your magnetic stirrer first (geometry comprised of a circle with an ellipse in the center). After this simpler model is fully functional, you can easily create and solve the 3D model too.