An Experimental Investigation of a Swirling Back Flow at Inlet of a Turbomachine Model

The present paper describes the experimental results of the influence of a bend type inlet on the swirling backflow by using the backflow model test rig. The backflow is generated by using a propeller with zero stagger blades. The backflow regions were observed by using a taft-stick and air bubbles. The backflow region thickness is not influenced by a bend type inlet so much. On the other hand, its length becomes shorter at the inner side and longer at the outer one. The fluctuation of the backflow region length becomes stronger for the bend type inlet than for the straight type one.