CALCULATION OF FLOW CHARACTERISTICS IN HEAT TURBOMACHINERY TURBINE STAGE WITH DIFFERENT THREE DIMENSIONAL SHAPE OF THE STATOR BLADE WITH ANSYS CFX SOFTWARE
Main purpose of the presented work was the investigation of influence of three dimensional blades over flow characteristics. The paper presents comparison between experimental and CFD (Computational Fluid Dynamics) data so called verification test, impulse turbine stage with Frozen Rotor and Transient Rotor Interface modeling. Static pressure distribution was measured at mid span of the blade. The paper discusses secondary flow phenomena.
Incidence Angle and Pitch-Chord Effects on Secondary Flows Downstream of a Turbine Cascade
This paper describes the results of an experimental investigation of the three-dimensional flow downstream of a linear turbine cascade at off-design conditions. The tests have been carried out for five incidence angles from −60 to +35 degrees, and for three pitch-chord ratios: s/c = 0.58,0.73,0.87. Data include blade pressure distributions, oil flow visualizations, and pressure probe measurements. The secondary flow field has been obtained by traversing a miniature five hole probe in a plane located at 50% of an axial chord downstream of the trailing edge. The distributions of local energy loss coefficients, together with vorticity and secondary velocity plots show in detail how much the secondary flow field is modified both by incidence and cascade solidity variations. The level of secondary vorticity and the intensity of the crossflow at the endwall have been found to be strictly related to the blade loading occurring in the blade entrance region. Heavy changes occur in the spanwise distributions of the pitch averaged loss and of the deviation angle, when incidence or pitch-chord ratio is varied.Copyright © 1992 by ASME
Effects of Incidence on Three-Dimensional Flows in a Linear Turbine Cascade
The paper describes effects of the incidence on cascade three-dimensional flows and on the associated loss mechanisms occurring in a low-speed linear turbine rotor cascade. For each of five nominal incidences ranging from 7.2 to −53.3 deg, the cascade flow was surveyed at 15 or 16 planes located axially throughout the cascade. Blade-to-blade flows at the cascade midspan and near the endwalls, meridional flows along the blade surfaces, and static and total pressures within the cascade were analyzed in detail. The results were represented by two- or three-dimensional tomograms, on the surfaces of which the cascade flows were drawn by vectors, scalar contours, and streaklines, and from which one can easily understand the extraordinarily complicated cascade flows and the loss generation mechanisms. The present study will not only give new insight into the incidence effects, but will also contribute many solid experimental facts of a quantitative nature to our current knowledge of turbine cascade flows.