检索结果-南通市图书馆

风机技术 2020年第6期62卷 7-17页

作者： Luca d'Agostino Department of Civil&Industrial Engineering Pisa University8 Via Gerolamo Caruso

The article illustrates the application of Bayesian estimation to the identification of flow instabilities,with special reference to rotating cavitation,in a three-bladed axial inducer using the unsteady pressure readings of a single transducer mounted on the casing just behind the leading edges of the impeller *** typical trapezoidal pressure distribution in the blade channels is parametrized and modulated in time and space for theoretically reproducing the expected pressure generated by known forms of cavitation instabilities(cavitation auto-oscillations and higher-order surge cavitation modes,n-lobed subsynchronous/synchronous/super-synchronous rotating cavitation).The Fourier spectra of the theoretical pressure so obtained in the rotating frame are transformed in the stationary frame,frequency broadened to better approximate the experimental results,and parametrically fitted by maximum likelihood estimation to the measured auto-correlation *** form of instability generates a characteristic distribution of sidebands in addition to its fundamental *** identification makes use of this information for effective detection and characterization of multiple simultaneous flow instabilities with intensities spanning over about 20 db down to about 4 db signal-to-noise *** same information also allows for effectively bypassing the aliasing limitations of traditional cross-correlation methods in the discrimination of multiple-lobed azimuthal instabilities from the measurements returned by arrays of equally spaced *** method returns both the estimates of the model parameters and their standard deviations,providing the information needed for the assessment of the statistical significance of the *** proposed approach represents therefore a promising tool for experimental research on flow instabilities in high-performance turbopumps.

关键词： rocket Propulsion liquid propellant rocket engines Turbomachinery Turbopumps Turbopump Cavitation Instabilities Parametric Identification

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

火箭发动机导流器和涡轮泵中空化不稳定性和转子动力学载荷（英文）

引用

风机技术 2018年第3期60卷 45-61页

作者： Luca d’Agostino Civil and Industrial Engineering Department University of Pisa

After a brief review of flow-induced instabilities in turbopumps for liquid propellant feed systems of modern rocket engines, some recent results of the work carried out by the author and his collaborators to elucidate the role of cavitation on the development of unsteady flow phenomena and rotordynamic impeller forces in these machines are illustrated. Specifically, the results are presented of a series of tests conducted in water in the Cavitating Pump Rotordynamic Test Facility(CPRTF) under similarity conditions on a threebladed, tapered-hub, high-head *** flow instabilities detected in these machines include axial cavitation surge oscillations, backflow oscillations, non-synchronous and synchronous(alternating blade) rotating cavitation, higher-order surge and higher-order rotating cavitation, depending on the operational conditions of the machine. The occurrence of these instabilities under the relevant operational conditions is critically *** characterization of the rotordynamic forces acting on the whirling impellers of the above machines under different load and cavitation conditions is also illustrated and discussed. The results have been obtained in the CPRTF by means of a novel experimental technique that allows for the continuous measurement of the rotordynamic force spectra as functions of the whirl ratio. Comparison with simultaneous high-speed movies of the inducer inlet flow highlights the relationship between the cavitation dynamics in the inducer backflow and the spectral behavior of the rotordynamic force as functions of the whirl ratio.

关键词： Turbomachines Turbopumps Aerospace Propulsion rocket Propulsion liquid propellant rocket engines liquid propellant Feed Turbopumps Two-Phase Flows Cavitation Inducers Unsteady Turbopump and Inducer Hydrodynamics Flow Instabilities Rotordynamics Rotordynamic Fluid Forces Cavitation-Induced Flow Instabilities

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

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

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

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：