1312 A Numerical Study of Backflow at the Inlet of 3-bladed Inducers

In order to analyze the occurrence mechanism of the backflow at the inlet of inducers, a series of numerical calculations were carried out including the different sizes of the tip clearance and the different geometry of the leading edges. Discussions are made based not only on the flow field at the inlet but also on the on the balance of the flow into/out from control volumes. The results show that the radial direction flow near the blade suction surface plays the main role in the formation of backflow. It is also shown that the leading edge gives an important influence for the backflow region