Abstract
We carried out numerical simulations of 2D unsteady cavitating flow in three-blade and four-blade cascades under the various operating conditions of inflow angle and cavitation number. The results showed that steady cavitating flow, which has the steadily distributed cavity on the blades, transited to unsteady states as inflow angle increases or cavitation number decreases. Consequently, it was found that the cavitating flow can be classified into steady or unsteady cavitation phenomena according to the operating condition regardless of the number of the blades. However, the patterns of unsteady cavitating flow in three-blade and four-blade cascades are not corresponding, such as rotating cavitation and alternative cavitation.
