Abstract
In the well-known rotating annulus experiments we applied liquid crystal techniques of visualization in order to obtain clear video-pictures of internal flow and temperature in the fluid. Then we developed an idea of injecting several types of liquid crystal with different temperature ranges simultaneously for observing the fluid having a wide temperature. We call it multiple liquid crystal techniques. Furthermore we use a table having double rotating disks, on the small one of which an annular tank is put and on the large one a video-camera is set. With these ideas clear video-pictures were possible to be taken throughout the entire region of the fluid. In this talk we show the video-pictures of the convections in the horizontal section near the bottom and in the meridional section of the fluid.
