Effect of Axial Gap on the Aerodynamics of 1 and 1.5 Stage Turbines

Abstract

Axial gap is one of the few important parameters that affect the performance of a turbine. Present work involves the computational study in 1 and 1.5 stage turbines with axial gaps of 15% and 50%. For each axial gap, investigation is done at three flow coefficients; namely, 0.68, 0.78 and 0.96. The turbine components nozzle, rotor and stator are modeled for both the axial gaps. Mid-span pressure distribution of the rotor for the design configuration is compared with the experimental results and found to be in good agreement. Total pressure, axial velocity, entropy and Mach number distributions along with torque are analyzed for all the configurations. Results indicate that the performance of the turbine is dependent on axial gap.