Effect of Bezier control points on blade pressure distribution

Abstract

Sensitivity of the shape of a turbine blade shapes on its performance is more compared to the compressor blade shape. Thus, a lot of research is concentrated on design of turbine blades and wide range of methods were suggested for the same. A blade with acceptable performance should have minimum of first order continuity along the blade curve. Discontinuity on the blade geometry leads to higher pressure gradient and affects the performance drastically. Hence, in this paper a turbine blade is generated, by using Bezier control points, to obtain a smooth blade curve. The blade is divided into leading section, main section and trailing section. The middle section of the blade is formed by cubic Bezier splines ensuring the first and second order continuity on the blade geometry. New blade geometries are formed by shifting the positions of the Bezier control points. The blade geometry formed from this newly shifted Bezier control points is subjected to the same boundary conditions as the baseline profile and the pressure distribution is analysed.The different blades generated are analysed in ANSYS FLUENT 17.2. The computational domain is a two dimensional turbine cascade, consisting of a turbine blade enclosed by periodic boundaries to mimic realistic conditions. A second order upwind strategy is used for inviscid flow analysis.