Aerodynamic Design of a Part-Span Tandem Bladed Rotor for Low Speed Axial Compressor / Fan

Tandem blades provide a very effective option to overcome the blade loading limitations. The flow from the pressure surface is used to energize the flow on the rear blade suction surface to avert impending flow separation. Based upon earlier experimental and CFD studies, as well as on results from other studies, a design philosophy was formulated to attempt the design of the hybrid tandem blades. This paper reports the design of a novel concept of hybrid rotor where the tandem configurations have been applied to only over the part of the span of the rotor blades. An aerodynamic design and experimental study of such a rotor was undertaken. The study indicated a remarkable performance improvement in the regions where tandem modifications were applied, which also promoted overall rotor performance enhancement. The hybrid tandem configuration provides a way to enhance the blade loading capacity and further optimize the aircraft engine compressor.