scholarly journals Design of New Three Stage Low Pressure Turbine for the BMW Rolls-Royce BR715 Turbofan Engine

1997 ◽  
Author(s):  
Keith Cobley ◽  
Neil Coleman ◽  
Gunnar Siden ◽  
Norbert Arndt
Keyword(s):  
Mechanical Design ◽  
Three Dimensional ◽  
Low Pressure ◽  
Advanced Technology ◽  
Pressure System ◽  
High Lift ◽  
Low Pressure Turbine ◽  
Simultaneous Design ◽  
Low Pressure System ◽  
Lp Turbine

In 1990, BMW and Rolls Royce plc (RR) joined to form a new company BWW-Rolls-Royce GmbH (BRR), to develop the BR700 family of engines aimed at the 12K and 25K lbs thrust range, using advanced technology and a modern organisation working in integrated teams to minimise the engine development timescales. After a successful development programme the BR710 engine rated at 14K lbs thrust, will shortly enter service in Gulfstream and Canadair Executive Jets. The recent launch of the BR715 engine at 21K lbs thrust, builds on the high pressure core developed for the BR710, plus a low pressure system with an increased diameter fan and 2 stage booster driven by a three stage turbine. This paper will describe, the advanced design technology incorporated, including the latest three dimensional aerodynamic philosophy using advanced high lift aerofoils for reduced parts count, plus the mechanical design issues addressed to optimise the LP turbine module configuration and the simultaneous design/make process employed to achieve the required parts delivery timescales.

Redesign of High-Lift LP-Turbine Airfoils for Low Speed Testing

2010 ◽  
Author(s):  
Michele Marconcini ◽  
Filippo Rubechini ◽  
Roberto Pacciani ◽  
Andrea Arnone ◽  
Francesco Bertini
Keyword(s):  
Separated Flow ◽  
Low Pressure ◽  
High Lift ◽  
Low Speed ◽  
Low Pressure Turbine ◽  
Wide Range ◽  
Flow Configurations ◽  
Artificial Neural Network Ann ◽  
Lp Turbine ◽  
Turbine Airfoils

Low pressure turbine airfoils of the present generation usually operate at subsonic conditions, with exit Mach numbers of about 0.6. To reduce the costs of experimental programs it can be convenient to carry out measurements in low speed tunnels in order to determine the cascades performance. Generally speaking, low speed tests are usually carried out on airfoils with modified shape, in order to compensate for the effects of compressibility. A scaling procedure for high-lift, low pressure turbine airfoils to be studied in low speed conditions is presented and discussed. The proposed procedure is based on the matching of a prescribed blade load distribution between the low speed airfoil and the actual one. Such a requirement is fulfilled via an Artificial Neural Network (ANN) methodology and a detailed parameterization of the airfoil. A RANS solver is used to guide the redesign process. The comparison between high and low speed profiles is carried out, over a wide range of Reynolds numbers, by using a novel three-equation, transition-sensitive, turbulence model. Such a model is based on the coupling of an additional transport equation for the so-called laminar kinetic energy (LKE) with the Wilcox k–ω model and it has proven to be effective for transitional, separated-flow configurations of high-lift cascade flows.

scholarly journals Assessing the Reliability of Global Monsoon Low Pressure System Track Datasets for the East Asian Monsoon

2021 ◽  
Author(s):  
Yanhong Zhang ◽  
Xiaohui Shi ◽  
Min Wen
Keyword(s):  
Asian Monsoon ◽  
East Asian Monsoon ◽  
East Asian ◽  
Three Dimensional ◽  
Low Pressure ◽  
Dimensional Structure ◽  
Observation Data ◽  
Pressure System ◽  
Global Monsoon ◽  
Low Pressure System

Abstract Limited by the lack of atmospheric observation data over the ocean and the absence of a comprehensive set of track data for monsoon low pressure systems (MLPSs), an in-depth understanding of the activity of East Asian MLPSs has not been acquired. In recent years, advancements in satellite remote sensing and data assimilation techniques have enabled the creation of numerous high-resolution global reanalysis datasets. Additionally, with the improvement of tracking algorithms, two sets of global MLPS track data (HB2015 and VB2020) have been published. This study seeks to understand the fidelity of the two datasets with respect to the East Asian monsoon. The genesis location, movement path, and three-dimensional structure of the East Asian MLPSs obtained using HB2015 and VB2020 are compared, and the atmospheric circulation conditions of typical MLPSs are analyzed. The results show that both datasets are able to generate MLPSs with identical structure for the East Asian Monsoon, and they provide similar results in terms of the location and monthly frequency. Compared to the HB2015, the VB2020 adopts a more stringent set of thresholds for the determination of the MLPS genesis and extinction and a more rigorous tracking algorithm. Therefore, it yields a lower count of MLPSs with significantly shorter lifetimes. However, the MLPSs identified by the VB2020 all have cyclonic circulations in the proximity of their central areas as they continue their movement. In this sense, the results generated by the VB2020 are more consistent with the observed MLPSs and hence are more reliable. However, the tracking can end prematurely with this dataset.

The Effects of Steady Injection on an Ultra High Lift Vane in a LP Turbine

2008 ◽  
Author(s):  
Thomas Schumann ◽  
Martin G. Rose ◽  
Stephan Staudacher ◽  
Jochen Gier ◽  
Th. Schro¨der
Keyword(s):  
Steady Flow ◽  
Flow Injection ◽  
Lift Coefficient ◽  
Suction Side ◽  
Low Pressure ◽  
Control Flow ◽  
Flow Area ◽  
High Lift ◽  
Low Pressure Turbine ◽  
Lp Turbine

The application of steady flow injection to control flow separation on the suction side of an ultra high lift low pressure turbine airfoil is presented. The blade lift coefficient of the ultra high lift airfoil at 1.46 Zweifel coefficient is considerably higher than those of conventional airfoils. Blade Reynolds numbers and blade dimensions are comparable to the first stages of aero engine low pressure turbines. The ultra high lift vane row is installed into a three stage low Mach number turbine test rig. Steady flow injection through suction side streamwise holes is investigated: with an angle to the surface of 45 deg. The pitch to diameter ratio is 10. The variation of the blowing ratio allows a closer study of the influence and effects occuing due to flow injection. Results show that steady flow injection can almost completely eliminate separation on the suction side. For four different blowing ratios blade pressure distribution and exit flow area traverse shows rising stage loading. A maximum of one percent change in flow exit angle was measured. The experimental results reveal that the injection jets only locally suppress the separation. This results in a spanwise variation in lift and trailing edge shed vortical structures.

Effect of Blade Profile Contouring on Endwall Flow Structure in a High-Lift Low-Pressure Turbine Cascade

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Keith Sangston ◽  
Jesse Little ◽  
M. Eric Lyall ◽  
Rolf Sondergaard
Keyword(s):  
Total Pressure ◽  
Three Dimensional ◽  
Low Pressure ◽  
Stereoscopic Particle Image Velocimetry ◽  
Loss Reduction ◽  
Mean Flow ◽  
High Lift ◽  
Computational Tools ◽  
Design Modification ◽  
Low Pressure Turbine

Previous work has shown that low-stagger contouring near the endwall of a nominally high-lift and high-stagger angle front-loaded low-pressure turbine (LPT) airfoil is successful in reducing endwall loss by limiting the development and migration of low momentum fluid associated with secondary flow structures. The design modification that leads to loss reduction in that study was determined from an intuitive approach based on the premise that reducing flow separation near the endwall will lead to reduced loss production. Those authors also relied heavily upon Reynolds-averaged Navier–Stokes (RANS) based computational tools. Due to uncertainties inherent in computational fluid dynamics (CFD) predictions, there is little confidence that the authors actually achieved true minimum loss. Despite recent advances in computing capability, turbulence modeling remains a shortcoming of modern design tools. As a contribution to overcoming this problem, this paper offers a three-dimensional (3D) view of the developing mean flow, total pressure, and turbulence fields that gave rise to the loss reduction of the airfoil mentioned above. Experiments are conducted in a linear cascade with aspect ratio of 3.5 and Re = 100,000. The results are derived from stereoscopic particle image velocimetry (PIV) and total pressure measurements inside the passage. Overall, the loss reduction correlates strongly with reduced turbulence production. The aim of this paper is to provide readers with a realistic view of mean flow and turbulence development that include all the components of the Reynolds stress tensor to assess, at least qualitatively, the validity of high fidelity computational tools used to calculate turbine flows.

Application of Nonaxisymmetric Endwall Contouring to Conventional and High-Lift Turbine Airfoils

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
T. J. Praisner ◽  
E. Allen-Bradley ◽  
E. A. Grover ◽  
D. C. Knezevici ◽  
S. A. Sjolander
Keyword(s):  
Design Methodology ◽  
Three Dimensional ◽  
Low Pressure ◽  
Free Form ◽  
Published Data ◽  
High Lift ◽  
Flow Solver ◽  
Low Pressure Turbine ◽  
Gradient Based ◽  
Endwall Contouring

Here, we report on the application of nonaxisymmetric endwall contouring to mitigate the endwall losses of one conventional and two high-lift low-pressure turbine airfoil designs. The design methodology presented combines a gradient-based optimization algorithm with a three-dimensional computational fluid dynamics (CFD) flow solver to systematically vary a free-form parameterization of the endwall. The ability of the CFD solver employed in this work to predict endwall loss modifications resulting from nonaxisymmetric contouring is demonstrated with previously published data. Based on the validated trend accuracy of the solver for predicting the effects of endwall contouring, the magnitude of predicted viscous losses forms the objective function for the endwall design methodology. This system has subsequently been employed to optimize contours for the conventional-lift Pack B and high-lift Pack D-F and Pack D-A low-pressure turbine airfoil designs. Comparisons between the predicted and measured loss benefits associated with the contouring for Pack D-F design are shown to be in reasonable agreement. Additionally, the predictions and data demonstrate that the Pack D-F endwall contour is effective at reducing losses primarily associated with the passage vortex. However, some deficiencies in predictive capabilities demonstrated here highlight the need for a better understanding of the physics of endwall loss-generation and improved predictive capabilities.

Application of Non-Axisymmetric Endwall Contouring to Conventional and High-Lift Turbine Airfoils

2007 ◽  
Author(s):  
T. J. Praisner ◽  
E. Allen-Bradley ◽  
E. A. Grover ◽  
D. C. Knezevici ◽  
S. A. Sjolander
Keyword(s):  
Design Methodology ◽  
Three Dimensional ◽  
Low Pressure ◽  
Companion Paper ◽  
Free Form ◽  
Published Data ◽  
High Lift ◽  
Low Pressure Turbine ◽  
Gradient Based ◽  
Endwall Contouring

Here we report on the application of non-axisymmetric endwall contouring to mitigate the endwall losses of one conventional- and two high-lift low-pressure turbine airfoil designs. The design methodology presented combines a gradient-based optimization algorithm with a three-dimensional CFD flow solver to systematically vary a free-form parameterization of the endwall. The ability of the CFD solver employed in this work to predict endwall loss modifications resulting from non-axisymmetric contouring is demonstrated with previously published data. Based on the validated trend accuracy of the solver for predicting the effects of endwall contouring, the magnitude of predicted viscous losses forms the objective function for the endwall design methodology. This system has subsequently been employed to optimize contours for the conventional-lift Pack B and high-lift Pack D-F and Pack D-A low-pressure turbine airfoil designs. Comparisons between the predicted and measured loss benefits associated with the contouring for Pack D-F design are shown to be in reasonable agreement. Additionally, the predictions and data demonstrate that the Pack D-F endwall contour is effective at reducing losses primarily associated with the passage vortex. However, some deficiencies in predictive capabilities demonstrate here highlight the need for a better understanding of the physics of endwall loss-generation and improved predictive capabilities. More detailed analysis of the contouring results for the Pack B design is presented in a companion paper (Knesevici et al. [1]).

Multilevel Turbofan Simulation Environment Based on MSC.SimManager’s SPDM-Technology

2015 ◽  
Author(s):  
Vladimir E. Makarov ◽  
Sergej P. Andreev ◽  
Jury P. Fedorchenko ◽  
Elena P. Pashkevitch ◽  
Yana V. Orlova
Keyword(s):  
Low Pressure ◽  
Simulation Environment ◽  
Web Portals ◽  
Pressure System ◽  
Aerodynamic Analysis ◽  
Base Content ◽  
Low Pressure Turbine ◽  
Geometry Model ◽  
Low Pressure System ◽  
Icem Cfd

The present work is devoted to some results of using the MSC.SimManager for development of Multilevel Turbofan Simulation Environment (MTSE). The current MTSE’s versions include: subsystem of turbofan’s design and simulation on 1D level; a subsystem of turbofan’s low pressure system (fan, booster, low pressure turbine) steady and unsteady aerodynamic analysis on 3D level; a subsystem of turbofan’s nacelle steady aerodynamic analysis including inlet, bypass and nozzles flows at 3D level. These subsystems based on CAE applications (in house and commercial) allow execution of all the necessary sequence of actions, including engine’s flow path parameters, geometry model adaptation (NX), mesh generation (ICEM-CFD), aerodynamic calculation (CIAM’s in house COBRA code), raw data processing (Tecplot, Excel). The MTSE is realized as specialized Web-portals and all the data and results are stored in a unified database with opportunity to audit each stage of process and all the data base content.

Design of an Intermediate Turbine Duct Downstream of a High Pressure Turbine

2016 ◽  
Author(s):  
Chaoshan Hou ◽  
Hu Wu
Keyword(s):  
High Pressure ◽  
Three Dimensional ◽  
Low Pressure ◽  
Aerodynamic Load ◽  
Duct Flow ◽  
Original Design ◽  
High Pressure Turbine ◽  
Intermediate Turbine Duct ◽  
Low Pressure Turbine ◽  
Inlet Conditions

The flow leaving the high pressure turbine should be guided to the low pressure turbine by an annular diffuser, which is called as the intermediate turbine duct. Flow separation, which would result in secondary flow and cause great flow loss, is easily induced by the negative pressure gradient inside the duct. And such non-uniform flow field would also affect the inlet conditions of the low pressure turbine, resulting in efficiency reduction of low pressure turbine. Highly efficient intermediate turbine duct cannot be designed without considering the effects of the rotating row of the high pressure turbine. A typical turbine model is simulated by commercial computational fluid dynamics method. This model is used to validate the accuracy and reliability of the selected numerical method by comparing the numerical results with the experimental results. An intermediate turbine duct with eight struts has been designed initially downstream of an existing high pressure turbine. On the basis of the original design, the main purpose of this paper is to reduce the net aerodynamic load on the strut surface and thus minimize the overall duct loss. Full three-dimensional inverse method is applied to the redesign of the struts. It is revealed that the duct with new struts after inverse design has an improved performance as compared with the original one.

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