FLOWS INDUCED IN A CYLINDER WITH BOTH END WALLS ROTATING

The flow field inside a cylindrical container induced by the rotation of the top and bottom end walls with a fixed sidewall is described. Fo r this problem, this paper shows that stagnation points occur along th e axis of rotation between the midplane of symmetry and the rotating e nd walls for appropriate values of the characteristic parameters, viz. , the Reynolds number and the aspect ratio of the container. Aspect ra tios of 0.5, 0.8, 1.0, and 1.5 were examined over a range of Reynolds numbers from 100 to 2000. As the Rcynolds number increased beyond a cr itical value a recirculation zone surrounding a columnar vortex core i n the meridional-plane flow pattern is predicted to occur near the mid plane. This toroidal vortex is different from the type B vortex breakd own phenomenon that occurs in cylindrical containers with only one end wall rotating.