U can try the effect of a magnetic field. Here are the materials required and method:
The Objective: The main concept in MHD is the interplay between an electric field and magnetic field. Both act on a moving conductive fluid and cause it to rotate by creating an creating a Lorentz force on this fluid. My project studied the effect of this force (via velocity), as an electric current was passed through a conducting fluid in the presence of a magnetic field.The independent variable was voltage, which was varied by using different batteries pre-set to different voltages. The dependent variable measured in the experiment was velocity. Different magnets were experimented with, including neodymium-iron-boron magnets and ceramic magnets. My hypothesis was that as voltage increased, velocity would increase as well.
Methods/Materials: Two electrodes were constructed by wrapping aluminum foil on the inside of a petri dish (outer electrode) and by rolling aluminum foil into a tight cylinder which was placed in the center of the dish (inner electrode.)The arrangement of magnets was placed underneath this dish, to keep magnetic field perpendicular to the current flow/drift velocity.From a strong conducting electrolyte solution (NaCl) to a weak conducting one (CuSO4 solution), 15 ml of each were measured for experimentation using a graduated cylinder.
Results: Overall, the trend seen in the experimental values was consistent with the calculated values. Calculated values were mathematically derived from the Lorentz force law.
Hope I helped you! :) Good luck with your model