Studies on the Flow Capture Through Blade Rows in a Two-Stage Axial Flow Turbine

In view of depleting fossil fuels and increasing demand for fuel, multi-stage axial flow turbines are being preferred because of increased power requirements. But flow turbine stage is very complex and increasing their performance further is a difficult task. In this context, the present study aims at computationally studying the flow phenomena in a two-stage turbine. Turbine components, nozzle and rotor of the first stage and stator and rotor 2 of the second stage are modelled and meshed. Total pressure and velocities in the stationary frame, static entropy and turbulent kinetic energy contours are drawn aiming blade-to-blade view and variation of these characterizes through the stage is analyzed. Pressure and velocity contours capture the flow pattern in terms of wakes, steadiness, energy conversion and impingement. Entropy contours reveal the aspect of overall losses in blade rows and TKE contours give the glimpse of turbulence in the flow. Contours at nozzle and stator exits presented a clear wake pattern. Pressure energy conversion is more in rotor 1 than rotor 2, i.e. more work is obtained from the first stage than the second stage. Suction side entropy values in case of rotor 1 are more than that of rotor 2. Rotor 1- stator interaction displayed more flow turbulence than the other interactions. Velocity vectors and streamlines have provided more clarity about flow separation and formation of vortices and wakes. Passage vortices are stronger in the second stage stator and rotor. Thus, in this work, flow capture through blade rows and its characteristics are studied.