A display mechanism for illustrating fluid dynamics includes a water basin having a base and a mass of water with a water surface within the basin. A waterwheel is supported within the basin. The waterwheel includes a plurality of pump tools equally spaced about the waterwheel and adapted to fill with water on one side of the waterwheel and to open on the other side of the waterwheel. Each of the pump tools includes three upwardly extending inner pipes. The plurality of pump tools are arranged to contact two outer pipes and are adapted to fill with water on one side of the water wheel.