Improving the Efficiency of the Trent 500 HP Turbine Using Non-Axisymmetric End Walls: Part II — Experimental Validation

2001 ◽  
Author(s):  
M. G. Rose ◽  
N. W. Harvey ◽  
P. Seaman ◽  
D. A. Newman ◽  
D. McManus
Keyword(s):  
Design Methodology ◽  
Experimental Validation ◽  
Axial Flow ◽  
Cfd Analysis ◽  
Hot Wire ◽  
Flow Conditions ◽  
Linear Cascade ◽  
Turbine Efficiency ◽  
End Wall ◽  
Turbine Model

Part I of this paper described how the HP turbine model rig of the Rolls-Royce Trent 500 was redesigned by applying non-axisymmetric end walls to both the vane and blade passages, whilst leaving the turbine operating point and overall flow conditions unaltered. This paper describes the results obtained from testing of the model rig and compares them with those obtained for the datum design (with conventional axisymmetric end walls). Measured improvements in the turbine efficiency are shown to be in line with those expected from the previous linear cascade research at Durham University, see Harvey et al. [1] and Hartland et al. [2]. These improvements are observed at both design and off-design conditions. Hot wire traverses taken at the exit of the rotor show, unexpectedly, that the end wall profiling has caused changes across the whole of the turbine flow field. This result is discussed making reference to a preliminary 3-D CFD analysis. It is concluded that the design methodology described in part I of this paper has been validated, and that non-axisymmetric end wall profiling is now a major new tool for the reduction of secondary loss in turbines (and potentially all axial flow turbomachinery). Further work, though, is needed to fully understand the stage (and multistage) effects of end wall profiling.

Improving Turbine Efficiency Using Non-Axisymmetric End Walls: Validation in the Multi-Row Environment and With Low Aspect Ratio Blading

2002 ◽  
Author(s):  
N. W. Harvey ◽  
G. Brennan ◽  
D. A. Newman ◽  
M. G. Rose
Keyword(s):  
Turbine Stage ◽  
Flow Conditions ◽  
Original Design ◽  
Linear Cascade ◽  
Hp Model ◽  
Low Aspect Ratio ◽  
Turbine Efficiency ◽  
Met Expectations ◽  
End Wall ◽  
Stage Efficiency

This paper describes how the Intermediate Pressure (IP) turbine model rig of the Rolls-Royce Trent 500 engine was redesigned by applying non-axisymmetric end walls to both the vane and blade passages. The blading aerofoil shapes, the turbine operating point and the overall flow conditions were unaltered from the original design. The results from testing of the model rig are presented and compared with those obtained previously for the datum design. A feature of this is that the IP turbine was tested in a “two-shaft” arrangement with the (upstream) Trent 500 High Pressure (HP) model turbine. Previously, non-axisymmetric end wall profiling had been shown to achieve a 0.59 ± 0.25% improvement in the stage efficiency of the Trent 500 HP model turbine when tested as a single stage, Rose et al. [1]. This had exceeded the design expectation of 0.4% improvement, Brennan et al. [4] — based on previous linear cascade research at Durham University, see Harvey et al. [2] and Hartland et al. [3]. The IP and HP turbines with profiled end walls were tested together, while for the datum test both model turbines had blading with axisymmetric end walls. The results have met expectations with an improvement in the IP turbine stage efficiency of 0.9 ± 0.4% at the design point. The turbine characteristics are shown to change significantly from the datum test.

scholarly journals CFD Analysis to Understand the Flow Behaviour of a Single Stage Transonic Axial Flow Compressor

2013 ◽  
Author(s):  
M. T. Shobhavathy ◽  
Premakara Hanoca
Keyword(s):  
Axial Flow ◽  
Flow Behaviour ◽  
Single Stage ◽  
Cfd Analysis ◽  
Flow Conditions ◽  
Blade Passage ◽  
Tip Leakage ◽  
Axial Flow Compressor ◽  
Design Speed ◽  
Flow Compressor

This paper comprises the Computational Fluid Dynamic (CFD) analysis to investigate the flow behaviour of a high speed single stage transonic axial flow compressor. Steady state analyses were carried out at design and part speed conditions to obtain the overall performance map using commercial CFD software ANSYS FLUENT. Radial distribution of flow parameters were obtained at 90% of design speed for the choked flow and near stall flow conditions. The predicted data were validated against available experimental results. The end wall flow fields were studied with the help of velocity vector plots and Mach number contours at peak efficiency and near stall flow conditions at 60% and 100% design speeds. This study exhibited the nature of a transonic compressor, having strong interaction between the rotor passage shock and the tip leakage vortex at design speed, which generates a region of high blockage in the rotor blade passage. The influence of this interaction extends around15% of the blade outer span at design speed and in the absence of blade passage shock at 60% design speed, the influence of tip leakage flow observed was around 8%.

A Fast Numerical Procedure to Solve the Meridional Equations of Motion in a Multistage Axial Flow Turbomachine

1981 ◽  
Author(s):  
A. Kündig
Keyword(s):  
Equations Of Motion ◽  
Computing Time ◽  
Axial Flow ◽  
Numerical Procedure ◽  
Flow Conditions ◽  
Compressor Blades ◽  
Streamline Curvature ◽  
Downstream Flow ◽  
Real Flow ◽  
End Wall

A new numerical procedure has been developed to solve the meridional equations of motion in an axial flow turbomachine. It is based on the so-called streamline-curvature method. The primary aim of this project was to reduce the computing-time of existing programs. The procedure has been tested. The new program is coupled with a program for the calculation of end-wall-boundary layers on axial flow compressors. This combination makes the simulation of real flow conditions possible. The pitch wise deviation angles and blade-row efficiencies are generally given as input. For compressor blades of the NACA-65-family they can be called from stored empirical data as function of geometry and the upstream and downstream flow conditions. The paper presents an exact description of the numerical procedure and a computed example.

Improving the Efficiency of the Trent 500 HP Turbine Using Non-Axisymmetric End Walls: Part 1 — Turbine Design

2001 ◽  
Author(s):  
G. Brennan ◽  
N. W. Harvey ◽  
M. G. Rose ◽  
N. Fomison ◽  
M. D. Taylor
Keyword(s):  
Large Scale ◽  
Design System ◽  
Linear Cascade ◽  
Low Speed ◽  
Significant Potential ◽  
Definition Of ◽  
Turbine Design ◽  
Shrouded Rotor ◽  
End Wall ◽  
Turbine Model

This paper describes the redesign of the HP turbine of the Rolls-Royce Trent 500 engine, making use of non-axisymmetric end walls. The original, datum turbine used conventional axisymmetric end walls, while the vane and (shrouded) rotor aerofoil profiles were nominally the same for the two designs. Previous research on the large scale, low speed linear cascade at Durham University, see Hartland et al [1], had already demonstrated significant potential for reducing turbine secondary losses using non-axisymmetric end walls - by about one third. This paper shows how a methodology was derived from the results of this research and applied to the design of the single stage Trent 500 HP turbine (model rig). In particular the application of a new linear design system for the parametric definition of these end wall shapes, described in Harvey et al [2], is discussed in detail.

Performance of a Compressor Cascade Configuration With Supersonic Entrance Flow—A Review and Comparison of Experiments in Three Installations

1988 ◽  
Vol 110 (4) ◽  
pp. 441-449 ◽  
Author(s):  
G. K. Serovy ◽  
T. H. Okiishi
Keyword(s):  
Axial Flow ◽  
Test Case ◽  
Test Cases ◽  
Data Sets ◽  
Flow Conditions ◽  
Compressor Cascade ◽  
Linear Cascade ◽  
Comparison Of Experiments ◽  
Blade Tip ◽  
Entrance Flow

A cascade geometry derived from a research program on high-throughflow, transonic, axial-flow compressors was tested with similar supersonic entrance flow conditions in three linear cascade test facilities. The airfoil section used was representative of advanced rotor-blade, tip-region profiles designed to operate at inlet relative Mach numbers of 1.4 to 1.8. Objectives in the experiments were to study the reproducibility of test conditions and measured performance in facilities that are considered to be “state-of-the-art,” and to generate data sets that could be used as test cases or “benchmark” results to validate computational methods for turbomachine application. It was recognized from the beginning of the project that the aerodynamic regime involved represents a very difficult combination of problems in both experimentation and computation. This difficulty was certainly encountered; the experimental problems are fully discussed in this paper and the companion papers originating in two of the test groups. An excellent series of data sets has been obtained, and our confidence in the results is supported by the exchange of information and personnel that occurred during all phases of the experiments. The results presented here and in the forthcoming AGARD Propulsion and Energetics Panel “test case” compendium should serve as a standard for evaluating current and future computational efforts.

The Application of Non-Axisymmetric Profiled End-Walls for Axial Flow Turbines in the Embedded Stage Environment

2013 ◽  
Author(s):  
Andreas Lintz ◽  
Liping Xu ◽  
Marios Karakasis
Keyword(s):  
Axial Flow ◽  
Leading Edge ◽  
Surface Flow ◽  
Secondary Flows ◽  
Experimental Results ◽  
Front Part ◽  
Flow Conditions ◽  
Suction Surface ◽  
Inlet Conditions ◽  
End Wall

In this paper, an assessment of the effectiveness of non-axisymmetric profiled end-walls in the embedded stage environment at varying inlet conditions is presented. Both numerical and experimental results were obtained in a three-stage model turbine which offers flow conditions representative of embedded blade rows in a typical high pressure steam turbine. The end-wall profile design was carried out using automatic optimization in conjunction with 3D RANS CFD. The design target is to reduce the end-wall losses by reducing the loading in the front part of the passage, which resulted in a single trough close to the blade suction surface in the leading edge region. 5-hole probe traverses and surface flow visualization show that the intensity of the secondary flows is reduced by about 10%, but overall loss is only reduced slightly. Experimental results have been obtained for the cylindrical end-wall and three different trough depths. With increasing depth, transitional effects at the end-walls might come into play, increasing the total pressure loss in the boundary layer region. The effects of the end-wall design is similar at positive and negative incidence, despite the reduced loading in the front part of the passage at negative incidence. At very high negative incidence angles, such as those occurring at the stator tip with rotor shroud leakage flows, the mechanism of secondary flow generation changes, so that a design under nominal inlet flow conditions shows no effect on the exit flow field.

Improving the Efficiency of the Trent 500-HP Turbine Using Nonaxisymmetric End Walls—Part I: Turbine Design

2003 ◽  
Vol 125 (3) ◽  
pp. 497-504 ◽  
Author(s):  
G. Brennan ◽  
N. W. Harvey ◽  
M. G. Rose ◽  
N. Fomison ◽  
M. D. Taylor
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Design System ◽  
Turbine Cascade ◽  
Linear Cascade ◽  
Definition Of ◽  
Turbine Design ◽  
Shrouded Rotor ◽  
End Wall ◽  
Turbine Model

This paper describes the redesign of the HP turbine of the Rolls-Royce Trent 500 engine, making use of nonaxisymmetric end walls. The original, datum turbine used conventional axisymmetric end walls, while the vane and (shrouded) rotor aerofoil profiles were nominally the same for the two designs. Previous research on the large-scale, low-speed linear cascade at Durham University (see Hartland et al., 1998, “Non-Axisymmetric End Wall Profiling in a Turbine Cascade,” ASME 98–GT-525), had already demonstrated significant potential for reducing turbine secondary losses using nonaxisymmetric end walls-by about one third. This paper shows how a methodology was derived from the results of this research and applied to the design of the single-stage Trent 500-HP turbine (model rig). In particular, the application of a new linear design system for the parametric definition of these end wall shapes (described in Harvey et al., 1999, “Non-Axisymmetric Turbine End Wall Design: Part I Three-Dimensional Linear Design System,” ASME 99–GT-337) is discussed in detail.

Flow through axial-flow-turbomachinery blading

2018 ◽  
Author(s):  
Marcel Escudier
Keyword(s):  
Flow Velocity ◽  
Compressible Flow ◽  
Dimensional Analysis ◽  
Incompressible Flow ◽  
Compressible Fluid ◽  
Axial Flow ◽  
Linear Cascade ◽  
Dimensional Parameters ◽  
Flow Through

This chapter is concerned primarily with the flow of a compressible fluid through stationary and moving blading, for the most part using the analysis introduced in Chapter 11. The principles of dimensional analysis are applied to determine the appropriate non-dimensional parameters to characterise the performance of a turbomachine. The analysis of incompressible flow through a linear cascade of aerofoil-like blades is followed by the analysis of compressible flow. Velocity triangles for flow relative to blades, and Euler’s turbomachinery equation, are introduced to analyse flow through a rotor. The concepts introduced are applied to the analysis of an axial-turbomachine stage comprising a stator and a rotor, which applies to either a compressor or a turbine.

Paper 10: Pressure Losses in the Inlet and Outlet Casings of Axial Flow Turbines for Turbo-Chargers

1967 ◽  
Vol 182 (4) ◽  
pp. 71-79 ◽  
Author(s):  
C. W. Simpson ◽  
D. E. Y. Scarlett
Keyword(s):  
Axial Flow ◽  
Annular Nozzle ◽  
Design Studies ◽  
Pressure Losses ◽  
Pressure Loss Coefficient ◽  
Turbine Efficiency ◽  
Annular Section ◽  
Turbine Casing ◽  
Transition Piece ◽  
Experimental Pressure

During initial design studies for a new range of turbo-chargers it was apparent that a considerable gain of efficiency could be achieved by a reduction of turbine casing losses. In this paper the theoretical and experimental pressure losses obtained from rig tests on the inlet and outlet casings for old and new designs will be presented. The inlet casing tests were completed on an axial entry casing with transition from circular to semi-annular section. The effect of this transition piece on gas incidences is also shown for the semi-annular nozzle entry. Studies on the outlet casing as a transition from annular through radial to axial flow have been completed and will be presented as a pressure loss coefficient for various designs. The tests have been undertaken with both convex and flat plate radial diffusers, with or without swirl. Different outlet ducts were used to determine the effects on pressure losses in the casings, and the results are discussed. Finally, the gains in overall turbine efficiency obtained by adopting the beneficial results from these tests are considered.

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