1Student, M. Sc. [Engg.], M.S. Ramaiah School of Advanced Studies, Bangalore, 560 054
2Professor, M.S. Ramaiah School of Advanced Studies, Bangalore, 560 054
3Professor and Center Manager (RMD), M.S. Ramaiah School of Advanced Studies, Bangalore, 560 054
A centrifugal compressor, with backward swept impeller, was designed for industrial applications and its performance was evaluated through numerical simulations. The baseline impeller geometry was then modified at the inducer leading edge to impart different forward and back sweeps. The inducer sweep was also associated with lean in the tangential direction. In all, seven impeller configurations were investigated, with inducer leading edge sweep varying from +25° (back sweep) to-20° (forward sweep). CFD simulations have indicated that the pressure ratio at design mass flow rate remained mostly unaffected by sweep, but showed a tendency to increase beyond an inducer back sweep of 20°. Similarly, a forward sweep of 20° gave lowest stall flow rate (highest stall margin). However, with an increase in tip clearance, the impeller with inlet forward sweep of 20° showed an increase in choke and stall mass flow rates. It is concluded that a forward sweep of 20°, with baseline tip clearance (0.5 mm), is beneficial in terms of high stall margin and acceptable peak pressure ratio as well as reasonably high efficiency.
Centrifugal Compressor, Inducer, Inlet Sweep, Tip Clearnce
