Design and Performance Investigations of Transonic Turbine Rotor Cascades

Abstract

The main focus of the thesis work is to investigate the performance and suitable design improvements of a transonic turbine rotor cascade. The Bezier parametric curve is used to represent the geometric blade definition. The semianalytical algorithm is developed to determine the control points of the Bezier curve which can reproduce the initial shape accurately with a minimum number of control points. The numerical flow field simulations are carried out using a cascade analysis code - MISES. The computational method - MISES has quite a good agreement with the experimental results. Two fold intuitive design change were employed namely curvature change along the rear part of suction side and reduction of trailing edge radius for the VKI-1 profile. Flow field simulations were carried out for four different profiles. The losses for profile-1, with trailing edge radius same as VKI-1 are reduced to about 2.5% for supersonic Mach number and shows a slight increase for Mach numbers 0.8 and 1.0. For profiles with reduced trailing edge radii, the losses are reduced around 3% for Mach numbers 0.8 and 1.0 and around 1% for Mach number 1.2 between the final and initial profile.