Modal Analysis on Impeller Rotor of the Axial Flow Pump based on Fluid-structure Interaction

This paper performed a numerical study into the dynamic stress improvement of an axial-flow pump and validated the simulation results with a prototype test. To further analyze the dynamic stress characteristics of impeller blades of axial-flow pumps, a bidirectional fluid–structure interaction (FSI) was applied to numerical simulations of the unsteady three-dimensional (3-D) flow field of the whole flow system of an axial-flow pump, and the gravity effect was also taken into account. In addition, real-structure-based single-blade finite element model was established. By using the finite element method, a calculation of the blade’s dynamic characteristics was conducted, and its dynamic stress distribution was determined based on the fourth strength theory. The numerical results were consistent with the prototype tests. In a rotation cycle, the dynamic stress of the blade showed a tendency of first increasing, and then decreasing, where the maximum value appeared in the third quadrant and the minimum appeared in the first quadrant in view of the gravity effect. A method for reducing the stress concentration near the root of impeller blades was presented, which would effectively alleviate the possibility of cracking in the unreliable region of blades. Simultaneously, an experimental method for the underwater measurement of the dynamic stress of prototypical hydraulic machinery was put forward, which could realize the underwater sealing of data acquisition instruments on rotating machinery and the offline collection of measured data, finally effectively measuring the stress of underwater moving objects.

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Comparative Analysis of Strength and Modal Characteristics of a Full Tubular Pump and an Axial flow Pump Impellers Based on Fluid-Structure Interaction

Energies ◽

10.3390/en14196395 ◽

2021 ◽

Vol 14 (19) ◽

pp. 6395

Author(s):

Lijian Shi ◽

Jun Zhu ◽

Li Wang ◽

Shiji Chu ◽

Fangping Tang ◽

...

Keyword(s):

Equivalent Stress ◽

Fluid Structure Interaction ◽

Axial Flow ◽

Total Deformation ◽

Stress Concentrations ◽

Pump Impeller ◽

Fluid Structure ◽

Structure Interaction ◽

Axial Flow Pump ◽

Flow Pump

Fluid-structure interaction (FSI) was used to determine the structural mechanical characteristics of full tubular and axial-flow pumps. The results showed that as the flow rate increases, the total deformation and equivalent stress are significantly reduced. The max total deformation (MTD) and the max equivalent stress (MES) of the full tubular pump impeller occur on the outer edge of the blade. There are two stress concentrations in the full tubular pump impeller, one of which is located in the outlet area of the rim, and the other is located in the outlet area of the hub. However, the MES of the axial-flow pump appears in the center of the blade hub. The performance difference between the full tubular pump and the axial-flow pump is mainly caused by the clearance backflow. The natural frequency of the full tubular pump is lower than that of the axial-flow pump on the basis of the modal results. The MES of the full tubular pump is mainly concentrated at the junction of the blade and the motor rotor, and the max thickness of the rim is 6mm, which can be more prone to cracks and seriously affect the safety and stability of the pump.

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Finite element computation for impeller of axial-flow pump based on fluid-structure interaction

2011 International Conference on Electrical and Control Engineering ◽

10.1109/iceceng.2011.6056975 ◽

2011 ◽

Cited By ~ 1

Author(s):

Weidong Shi ◽

Guotao Wang

Keyword(s):

Finite Element ◽

Fluid Structure Interaction ◽

Axial Flow ◽

Fluid Structure ◽

Structure Interaction ◽

Element Computation ◽

Axial Flow Pump ◽

Finite Element Computation ◽

Flow Pump

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Analysis of Strength and Modal Characteristics of a Full Tubular Pump Impeller Based on Fluid-Structure Interaction

10.21203/rs.3.rs-627588/v1 ◽

2021 ◽

Author(s):

Lijian Shi ◽

Jun Zhu ◽

Li Wang ◽

Shiji Chu ◽

FangPing Tang ◽

...

Keyword(s):

Equivalent Stress ◽

Fluid Structure Interaction ◽

Axial Flow ◽

Total Deformation ◽

Stress Concentrations ◽

Pump Impeller ◽

Fluid Structure ◽

Structure Interaction ◽

Axial Flow Pump ◽

Flow Pump

Abstract FSI(Fluid-Structure Interaction) is used to perform the the structural mechanical characteristics on the full tubular and the axial-flow pumps. The results show that as the flow rate increases, the total deformation and equivalent stress are significantly reduced. The MTD(max total deformation) and the MES(max equivalent stress) of the full tubular pump impeller appear at the outer edge of the blade. There are two stress concentrations in the full tubular pump impeller, in which one is located in the outlet area of the rim, and the other is located in the outlet area of the hub. However, the MES of the axial-flow pump appears at the center of the blade hub. The performance difference between the full tubular pump and the axial-flow pump is mainly caused by the clearance backflow. The natural frequency of the full tubular pump is lower than that of the axial-flow pump according to the modal results. The MES of the full tubular pump is mainly concentrated at the junction of the blade and the motor rotor, and the max thickness of the rim is 6mm, which is more prone to cracks, seriously affecting the safety and stability of the pump.

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The Numerical Simulation of Fluid-Structure Interaction on a Simple Cluster in an Axial Flow

Fluid-Structure-Sound Interactions and Control - Lecture Notes in Mechanical Engineering ◽

10.1007/978-3-642-40371-2_57 ◽

2013 ◽

pp. 399-403

Author(s):

Z. G. Liu ◽

Y. Liu ◽

J. Lu

Keyword(s):

Numerical Simulation ◽

Fluid Structure Interaction ◽

Axial Flow ◽

Fluid Structure ◽

Structure Interaction

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A Homogenization Method for the Modal Analysis of a Nuclear Reactor With Fluid-Structure Interaction

Volume 4: Fluid Structure Interaction, Parts A and B ◽

10.1115/pvp2006-icpvt-11-93013 ◽

2006 ◽

Cited By ~ 2

Author(s):

Jean-Franc¸ois Sigrist ◽

Daniel Broc

Keyword(s):

Modal Analysis ◽

Nuclear Reactor ◽

Mass Operator ◽

Fluid Structure Interaction ◽

Homogenization Method ◽

Theoretical Point ◽

Element Discretization ◽

Fluid Structure ◽

Structure Interaction ◽

Internal Structures

The present paper exposes a homogenization method developed in order to perform the modal analysis of a nuclear reactor with fluid-structure interaction effects. The homogenization approach is used in order to take into account the presence of internal structures within the pressure vessel. A homogenization method is proposed in order to perform a numerical calculation of the frequencies and modal masses for the eigenmodes of the coupled fluid-structure problem. The technique allows the use of a simplified fluid-structure model that takes into account the presence of internal structures: the theory bases are first recalled, leading to a new formulation of the fluid-structure coupled problem. The finite element discretization of the coupled formulation leads to the modification of the classical fluid-structure interaction operators. The consistency of the formulation is established from a theoretical point of view by evaluating the total mass of the coupled system with the fluid and structure mass operator, and the modified added mass operator. The method is tested and validated on a 2D case (two concentric cylinders with periodical rigid inclusions within the annular space) and applied on the industrial case. A complete modal analysis (calculation of frequencies and modal masses) is performed on a simplified geometry of a nuclear reactor with and without internal structures. Numerical results are then compared and discussed, and the influence of the internal structures on the fluid-structure coupled phenomenon is highlighted.

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Modal Analysis of Fluid-Structure Interaction in a Bent Pipeline

BATH/ASME 2016 Symposium on Fluid Power and Motion Control ◽

10.1115/fpmc2016-1705 ◽

2016 ◽

Cited By ~ 2

Author(s):

Gudrun Mikota ◽

Rainer Haas ◽

Evgeny Lukachev

Keyword(s):

Modal Analysis ◽

Degrees Of Freedom ◽

Coupling Effect ◽

Fluid Structure Interaction ◽

Interaction Model ◽

Coupling Mechanism ◽

Fluid Structure ◽

Structure Interaction ◽

Resonance Coupling ◽

Measured Frequency Response

Fluid-structure interaction in a bent pipeline is investigated by modal methods. Measured frequency response functions between flow rate excitation and pressure response indicate a coupling effect near the third pipeline resonance. Using modal coordinates for the hydraulic and the mechanical subsystems, a two-degrees-of-freedom study of resonance coupling is carried out. An experimental modal analysis of the coupled hydraulic-mechanical system confirms the predicted resonance splitting; it illustrates the coupling mechanism and shows the relevant mechanical part. An analytical fluid-structure interaction model succeeds in reproducing the measured coupling effect. This model is also used for modification prediction; it demonstrates that an appropriate assembly of mass and damping on the pipeline can help to reduce hydraulic resonance amplitudes.

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