Rheologica Acta, Vol.60, No.4, 175-186, 2021
Lift, drag and torque on a rotating sphere in a stream of non-Newtonian power-law fluid
The flow of a non-Newtonian, power-law fluid, directed normally to a rotating sphere is considered in the present paper. The problem is investigated by means of a three-dimensional numerical simulation with the SIMPLE algorithm. The investigation covers the power-law index from 0.2 up to 2, rotation rate from 0.1 up to 3 and Reynolds number from 0.1 up to 100. The following general rules are valid. The lift coefficient increases with increasing the rotation rate. At high Re numbers the drag coefficient increases with the power-law index. At high Re numbers the torque coefficient increases with the power-law index and with the rotation rate, whereas the torque coefficient reduces as the Reynolds number increases. In addition, there are some special cases which are analyzed in the text.