ABSTRACT
Problems and solutions presented in this chapter deal with the preliminary design of diffusers. They include determining the outlet-to-inlet area ratio of a gas turbine annular exhaust diffuser, analyzing the exhaust diffuser of a land-based gas turbine for power generation, evaluating two supersonic air flow diffuser designs: (1) a convergent-divergent nozzle with a normal shock exhausting into a diffuser and (2) convergent-divergent diffuser with variable throat area to swallow the starting shock, comparing actual pressure rise coefficient with the theoretical (incompressible) value for diffusion in a row of axial-flow compressor blades, finding the dependence of turbine power output on exhaust diffuser pressure rise coefficient, analyzing an incompressible flow through a frictionless adiabatic duct with and without a diffuser, and analyzing an incompressible flow in an adiabatic diffuser with a bypass duct. Detailed discussions of various concepts behind the problems and solutions presented in this chapter may be found in Logan’s Turbomachinery: Flowpath Design and Performance Fundamentals, Third Edition, by Bijay K. Sultanian, published by Taylor & Francis in 2015.
