Fluid flows in precessing spherical shells

Numerical solutions for fluid flows in precessing spherical cavities and sp herical shells have been obtained and are compared with earlier analytical expressions. It is shown that the approximate validity of the analytical ex pressions extends further than could have been expected. The details of the flow structure exhibit significant departures, however, from the assumptio ns of the analytical theory. Standing waves are found in the case of suffic iently thin shells. Some results on instabilities of the basic flow are als o discussed.