Endwall Loss in Turbine Cascades
- 15 March 2017
- journal article
- Published by ASME International in Journal of Turbomachinery
- Vol. 139 (8), 081004
- https://doi.org/10.1115/1.4035663
Abstract
Prior to the detailed design of components, turbomachinery engineers must guide a mean-line or throughflow design toward an optimum configuration. This process requires a combination of informed judgement and low-order correlations for the principle sources of loss. With these requirements in mind, this paper examines the impact of key design parameters on endwall loss in turbines, a problem which remains poorly understood. This paper presents a parametric study of linear cascades, which represent a simplified model of real-engine flow. The designs are nominally representative of the low-pressure turbine blades of an aero-engine, with varying flow angles, blade thickness, and suction surface lift styles. Reynolds-averaged Navier–Stokes (RANS) calculations are performed for a single aspect ratio (AR) and constant inlet boundary layer thickness. To characterize the cascades studied, the two-dimensional design space is examined before studying endwall losses in detail. It is demonstrated that endwall loss can be decomposed into two components: one due to the dissipation associated with the endwall boundary layer and another induced by the secondary flows. This secondary-flow-induced loss is found to scale with a measure of streamwise vorticity predicted by classical secondary flow theory.Keywords
This publication has 29 references indexed in Scilit:
- A Numerical Investigation Into the Sources of Endwall Loss in Axial Flow TurbinesPublished by ASME International ,2012
- An Experimental and Computational Study of the Formation of a Streamwise Shed Vortex in a Turbine StageJournal of Turbomachinery, 2003
- Secondary Flows in Axial Turbines—A ReviewAnnals of the New York Academy of Sciences, 2001
- Analysis and interpretation of instantaneous turbulent velocity fieldsExperiments in Fluids, 2000
- The 1993 IGTI Scholar Lecture: Loss Mechanisms in TurbomachinesJournal of Turbomachinery, 1993
- Recent Progress in the Understanding of Basic Aspects of Secondary Flows in Turbine Blade PassagesJournal of Engineering for Gas Turbines and Power, 1985
- A Mean Line Prediction Method for Axial Flow Turbine EfficiencyJournal of Engineering for Power, 1982
- Improvements to the Ainley-Mathieson Method of Turbine Performance PredictionJournal of Engineering for Power, 1970
- Performance Estimation of Axial Flow TurbinesProceedings of the Institution of Mechanical Engineers, 1970
- ROTATIONAL FLOW THROUGH CASCADES PART I. THE COMPONENTS OF VORTICITYThe Quarterly Journal of Mechanics and Applied Mathematics, 1955