检索结果-南通市图书馆

Unsteady Inflow Effects on the Wake Shed from a High-Lift LPT Blade Subjected to Boundary Layer Laminar Separation

Journal of Thermal Science 2012年第2期21卷 97-108页

作者： Francesca Satta Marina Ubaldi pietro zunino Università degli Studi di Genova

An experimental investigation on the near and far wake of a cascade of high-lift low-pressure turbine blades subjected to boundary layer separation over the suction side surface has been carried out, under steady and unsteady inflows. Two Reynolds number conditions, representative of take-off/landing and cruise operating conditions of the real engine, have been tested. The effect of upstream wake-boundary layer interaction on the wake shed from the profile has been investigated in a three-blade large-scale linear turbine cascade. The comparison between the wakes shed under steady and unsteady inflows has been performed through the analysis of mean velocity and Reynolds stress components measured at midspan of the central blade by means of a two-component crossed miniature hot-wire probe. The wake development has been analyzed in the region between 2% and 100% of the blade chord from the central blade trailing edge, aligned with the blade exit direction. Wake integral parameters, half-width and maximum velocity defects have been evaluated from the mean velocity distributions to quantify the modifications induced on the vane wake by the upstream wake. Moreover the thicknesses of the two wake shear layers have been considered separately in order to identify the effects of Reynolds number and incoming flow on the wake shape. The self-preserving state of the wake has been looked at, taking into account the different thicknesses of the two shear layers. The evaluation of the power density spectra of the velocity fluctuations allowed the study of the wake unsteady behavior, and the detection of the effects induced by the different operating conditions on the trailing edge vortex shedding.

关键词： Wake-wake unsteady interaction high-lift blade profiles low-pressure turbine blade wake.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An Experimental Investigation of the Dissipation Mechanisms in the Suction Side Boundary Layer of a Turbine Blade

引用

Journal of Thermal Science 2008年第4期17卷 289-297页

作者： Francesca Satta Daniele Simoni Marina Ubaldi pietro zunino Dipartimento di Macchine Sistemi Energetici e Trasporti-Università di Genova

The present work is part of an extensive experimental activity carried out by the authors in recent years aimed at investigating the boundary layer transition phenomenon in turbine blades. The large scale of the cascade and the use of advanced LDV instrumentation and precision probe traversing mechanism resulted in high degree of spatial resolution and high accuracy of measurements. The main dissipation mechanism determining the profile losses in turbomachinery blades is the work of deformation of the mean motion within the boundary layer operated by both viscous and turbulent shear stresses. In the present paper, the local viscous and turbulent deformation works have been directly evaluated from the detailed measurements of boundary layer mean velocity and Reynolds shear stress. The results show the distributions and the relative importance of the viscous and turbulent contributions to the loss production, in relation with the boundary layer states occurring along the turbine profile.

关键词： Axial flow turbines Profile boundary layer Energy dissipation mechanism Boundary layer transition Laser Doppler measurements.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experimental and Numerical Analysis of Cavity/Mean-Flow Interaction in Low Pressure Axial Flow Turbines

引用

Journal of Thermal Science 2021年第6期30卷 2178-2185页

作者： BARSI Dario COSTA Carlo LENGANI Davide SIMONI Daniele VENTURINO Giulio zunino pietro DIME-Universita di Genova Via Montallegro 11-16145 Genova

The increasing performance of modern aeroengines led the research towards the optimization of machine components not deeply analyzed in the *** this context,the mechanisms driving the interaction process between the secondary flows evolving at the hub of low-pressure turbines with the rotor-stator cavity systems have been poorly investigated in the *** this work,an experimental and numerical analysis of the interaction between the endwall near wall flow and the leakage flow of a real cavity system is *** experimental results were carried out in the annular low-pressure axial flow turbine of the University of *** blade loading and pressure distributions into the cavity,as well as the measured total pressure loss coefficient,have been used for a proper validation of CFD *** steady and unsteady calculations were carried out through the commercial solver ***,several numerical approaches have been tested into this work:RANS,Non Linear Harmonic(NLH),and *** most promising CFD techniques have been firstly identified by comparison with experimental results and then systematically employed to extend the analysis of secondary flow-cavity flow interaction to positions and quantities not available from the *** characterizing the mean flow-cavity flow interaction process will be shown to cover a great amount of the overall stage losses and should be properly accounted for the design of future optimized cavity configurations.

关键词： axial flow turbine cavity mean-flow interaction experimental analysis CFD

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experimental Analysis of the Aerodynamic Performance of an Innovative Low Pressure Turbine Rotor

引用

Journal of Thermal Science 2016年第1期25卷 22-31页

作者： Infantino Daniele Satta Francesca Simoni Daniele Ubaldi Marina zunino pietro Bertini Francesco DIME-Universita degli Studi di Genova Via MontaUegro 11-16145 GenovaItaly Avio Aero Viale I Maggio 56I-10040 Rivalta(TO)-Italy

In the present work the aerodynamic performances of an innovative rotor blade row have been experimentally investigated. Measurements have been carried out in a large scale low speed single stage cold flow facility at a Reynolds number typical of aeroengine cruise, under nominal and off-design conditions. The time-mean blade aerodynamic loadings have been measured at three radial positions along the blade height through a pressure transducer installed inside the hollow shaft, by delivering the signal to the stationary frame with a slip ring. The time mean aerodynamic flow fields upstream and downstream of the rotor have been measured by means of a five-hole probe to investigate the losses associated with the rotor. The investigations in the single stage research turbine allow the reproduction of both wake-boundary layer interaction as well as vortex-vortex interaction. The detail of the present results clearly highlights the strong dissipative effects induced by the blade tip vortex and by the momentum defect as well as the turbulence production, which is generated during the migration of the stator wake in the rotor passage. Phase-locked hot-wire investigations have been also performed to analyze the time-varying flow during the wake passing period. In particular the interaction between stator and rotor structures has been investigated also under off-design conditions to further explain the mechanisms contributing to the loss generation for the different conditions.

关键词： Low Pressure Turbine Single Stage Research Turbine Rotor Aerodynamic Loading Hot-wire Anemometry

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Compressor and Turbine Multidisciplinary Design for Highly Efficient Micro-gas Turbine

引用

Journal of Thermal Science 2018年第3期27卷 259-269页

作者： BARSI Dario PERRONE ANDrea QU Yonglei RATTO Luca RICCI Gianluca SERGEEV Vitaliy zunino pietro Department of Mechanical Energy Management and Transport Engineering Università degli Studi di Genova Faculty of Power and Energy Engineering Harbin Engineering University Institute of Energy and Transport Systems "Peter the Great" St. Petersburg Polytechnic University

Multidisciplinary design optimization （MDO） is widely employed to enhance turbomachinery compo- nents efficiency. The aim of this work is to describe a complete tool for the aero-mechanical design of a radial in- flow turbine and a centrifugal compressor. The high rotational speed of such machines and the high exhaust gas temperature （only for the turbine） expose blades to really high stresses and therefore the aerodynamics design has to be coupled with the mechanical one through an integrated procedure. The described approach employs a fuUy 3D Reynolds Averaged Navier-Stokes （RANS） solver for the aerodynamics and an open source Finite Element Analysis （FEA） solver for the mechanical integrity assessment. Due to the high computational cost of both these two solvers, a meta model, such as an artificial neural network （ANN）, is used to speed up the optimization design process. The interaction between two codes, the mesh genera- tion and the post processing of the results are achieved via in-house developed scripting modules. The obtained results are widely presented and discussed.

关键词： Micro-gas turbine Multidisciplinary Optimization Centrifugal Compressor Centripetal Turbine

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Design of a Centrifugal Compressor for Micro Gas Turbine: Investigation of Scaling and Tip Clearance Effects

引用

Open Journal of Fluid Dynamics 2019年第1期9卷 49-62页

作者： Dario Barsi Alberto Bottino Andrea Perrone Luca Ratto pietro zunino Department of Mechanical Energy Management and Transportation Engineering University of Genova Genova Italy

The aim of this paper is to investigate the design in similarity of a centrifugal compressor for micro gas turbine and the related scaling effects on performance using CFD investigations. This work is part of a research project carried out by the Department DIME of the University of Genova, with the purpose of investigating the performance of a micro gas turbine in the change from 100 kW electrical output to 250 kW, while maintaining the compressor pressure ratio and geometry in similarity. The first part of the work focuses on the comparison between the original and the scaled machine, while the second part of the study deeply investigates the tip gap effect in the new configuration. The aim is to provide information about the performance of the compressor designed in geometrical similarity and to evaluate the tip gap height impact. From the efficiency point of view, the scaled-up machine has higher efficiency (up to 1.4% increment in design conditions) keeping the same technological limit for impeller manufacturing. However, the variation of tip gap height in the range 0 ÷ 1 mm strongly affects this parameter, leading to 10% alteration in design conditions between the ideal and worst case. The results, both in terms of overall performance and flow fields, are widely discussed in order to obtain simple yet reliable correlation for preliminary design.

关键词： Centrifugal Compressor Scaling Tip Gap CFD

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：