Study on Flow Characteristics in Volute of Centrifugal Pump Based on Dynamic Mode Decomposition

Li, Yibin; He, Chang-hong; Li, Jianzhong

doi:10.1155/2019/2567659

Cited by 10 publications

(5 citation statements)

References 22 publications

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“…Liu et al [71] The velocity distribution and oscillation characteristics of the volute under nominal and low flow-rate conditions were obtained using DMD Li et al [72] The DMD method was applied to analyze pressure fluctuations within the volute, taking into account the unsteady flow conditions in centrifugal pumps with varying trailing edge shapes.…”

Section: Liu Et Al [70]mentioning

confidence: 99%

Data-Driven Modal Decomposition Methods as Feature Detection Techniques for Flow Fields in Hydraulic Machinery: A Mini Review

Xu,

Zhang,

Zhang

et al. 2024

JMSE

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Cavitation is a quasi-periodic process, and its non-stationarity leads to increasingly complex flow field structures. On the other hand, characterizing the flow field with greater precision has become increasingly feasible. However, accurately and effectively extracting the most representative vibration modes and spatial structures from these vast amounts of data has become a significant challenge. Researchers have proposed data-driven modal decomposition techniques to extract flow field information, which have been widely applied in various fields such as signal processing and fluid dynamics. This paper addresses the application of modal decomposition methods, such as dynamic mode decomposition (DMD), Proper Orthogonal Decomposition (POD), and Spectral Proper Orthogonal Decomposition (SPOD), in cavitation feature detection in hydraulic machinery. It reviews the mathematical principles of these three algorithms and a series of improvements made by researchers since their inception. It also provides examples of the applications of these three algorithms in different hydraulic machinery. Based on this, the future development trends and possible directions for the improvement of modal decomposition methods are discussed.

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Section: Liu Et Al [70]mentioning

confidence: 99%

Data-Driven Modal Decomposition Methods as Feature Detection Techniques for Flow Fields in Hydraulic Machinery: A Mini Review

Xu,

Zhang,

Zhang

et al. 2024

JMSE

View full text Add to dashboard Cite

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“…Li et al. obtained the velocity mode contour and oscillation characteristics of the mid-span of the centrifugal pump casing under rated and low-flow conditions using the DMD method and reconstructed the internal flow field of the volute [36]. Liu et al.…”

Section: Introductionmentioning

confidence: 99%

A Comparative Study of the Mode-Decomposed Characteristics of the Asymmetricity of a Vortex Rope with Flow Rate Variation

Li,

Guang,

Yang

et al. 2024

Symmetry

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In hydro turbines, the draft tube vortex rope is one of the most crucial impact factors causing pressure pulsation and vibration. It is affected by operating conditions due to differences in the flow rate and state and can be symmetric or asymmetric along the rotational direction. It may influence the stability of draft tube flow. To achieve a better understanding, in this work, dynamic mode decomposition is used in a draft tube case study of a simplification of a vortex rope. As the flow rate increases, the shape of the vortex rope becomes clear, and the flow rotation becomes more significant as the inlet flow rate increases. Dynamic mode decomposition was used to determine the relative frequencies, which were 0 (averaged), 0.7 times, and 1.4 times the features of the reference frequency. As the inlet flow rate increases, the order of high-energy modes and their influence on the vortex rope gradually increase, and this characteristic is exhibited further downstream of the draft tube. When the inlet flow rate is low, the impact of mode noise is greater. As the flow velocity increases, the noise weakens and the rotation mode becomes more apparent. Identifying the mode of the vortex flow helps extract characteristics of the vortex rope flow under different operating conditions, providing a richer data-driven basis for an in-depth analysis of the impact of operating conditions on the flow stability of a draft tube.

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“…The DMD method was first proposed by Schmid [24,25], and with the development of experimental technology and numerical calculations, it has been widely employed in the analysis of various flow phenomena [26][27][28][29][30]. For example, the DMD method has been used to analyze the internal flow structures of rotating machinery [31][32][33][34][35][36]. DMD primarily focuses on analyzing the changes in a variable field at specific frequencies, with a significant impact on the flow field resulting from changes in the trailing edge.…”

Section: Introductionmentioning

confidence: 99%

Influence of the Trailing Edge Shape of Impeller Blades on Centrifugal Pumps with Unsteady Characteristics

Song,

Chen,

et al. 2024

Processes

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The flow field structure and pressure pulsation characteristics in two series of trailing edges of a centrifugal pump are investigated using the SST k-w turbulence model. Series 1 involves varying the impeller exit angle, and Series 2 involves varying the impeller exit shape. The entropy generation rate analysis method is used to evaluate the numerical simulation results. Vortex cores within the flow field are identified by applying the Ω criterion. The influence of different trailing edge configurations on the energy loss characteristics of the pumps is explored. The dynamic mode decomposition (DMD) method is used to analyze pressure pulsations at the volute considering unsteady flows in centrifugal pumps with different trailing edge shapes. The findings suggest that different trailing edge shapes can be used to adjust the energy loss proportions in various components of the pump. In Series 1, the efficiency remains nearly constant with changes in the outlet angle on both sides of the trailing edge. In Series 2, the efficiency is enhanced by 1.18% with the elliptical edge shape on both sides (EBS) compared to the original trailing edge (OTE) shape. In Series 1 and Series 2, greater entropy generation rates are accompanied by greater pressure pulsations at the pump outlet. The DMD results demonstrate a noticeable impact of the different trailing edges on the pressure distribution of various modes within the volute. Moreover, the impeller outlet pressure inhomogeneity coefficient changes under different modes. This study holds great significance for selecting the appropriate trailing edges for centrifugal pumps.

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Study on Flow Characteristics in Volute of Centrifugal Pump Based on Dynamic Mode Decomposition

Cited by 10 publications

References 22 publications

Data-Driven Modal Decomposition Methods as Feature Detection Techniques for Flow Fields in Hydraulic Machinery: A Mini Review

Data-Driven Modal Decomposition Methods as Feature Detection Techniques for Flow Fields in Hydraulic Machinery: A Mini Review

A Comparative Study of the Mode-Decomposed Characteristics of the Asymmetricity of a Vortex Rope with Flow Rate Variation

Influence of the Trailing Edge Shape of Impeller Blades on Centrifugal Pumps with Unsteady Characteristics

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