Compressor is a crucial component of an engine. Flow through the compressor is intricate and sensitive to the reference frame, geometry of the blade, tip clearance, stator, staging, etc. Compressor, though designed for a particular environment, is also expected to show its performance under off design conditions like accelerating flight, landing, take off, climbing etc. The flow in third dimension leads to many complications and ambiguity. Tip aerodynamics, passage flow, and vortex aerodynamics play crucial role in describing the flow through the upper half of the blade and in the tip region, whereas flow over blade surface, trailing edge and the hub will guide the aerodynamic behavior of the rotor blade. This exercise is done for off design environment to study the aforesaid flow characteristics and is carried on an axial flow fan. The performance variation of fan flow under varying flow conditions is analyzed.