Characteristics of Centrifugal Pump Rotor System Under Exciting Forces Generated by Shroud Leakage Flows

2010 ◽  
Author(s):  
Quan-zhong Liu ◽  
Ru-zhi Gong ◽  
Hong-jie Wang ◽  
Yang Yao
Keyword(s):  
Centrifugal Pump ◽  
Rotor System ◽  
Least Square ◽  
Force Model ◽  
Dynamic Force ◽  
Pump Rotor ◽  
Leakage Flows ◽  
Exciting Forces ◽  
Rotordynamic Forces ◽  
Turbo Pump

In order to investigate the flow-induced vibration in the impeller clearance of centrifugal pump, and make the rotordynamic prediction of the centrifugal pump rotor system, a rotordynamic force model is established which is indispensable to the impeller-rotor system dynamics analysis. The coefficient in the dynamic force model is solved by quasi-steady CFD solution. Multiple quasi-steady solutions of an eccentric three-dimensional model at a series of relative spin velocity yield the rotordynamic forces at different whirl frequency ratios, and a second-order least-square fitting of the rotordynamic forces generates the skew-symmetric stiffness, damping, and mass matrices. Based on the work, the finite element method is applied to establish the model of turbo pump impeller-rotor system. The phenomenon of the fluid oscillation and some typical features are explained from the perspective of oscillation fluid mechanics. The results show complicated frequency characteristics presents in the turbo pump rotor vibration due to the exciting forces generated by shroud leakage flows.

scholarly journals The Effect of Inlet Swirl on the Rotordynamic Shroud Forces in a Centrifugal Pump

1992 ◽  
Author(s):  
A. Guinzburg ◽  
C. E. Brennen ◽  
A. J. Acosta ◽  
T. K. Caughey
Keyword(s):  
Centrifugal Pump ◽  
Guide Vane ◽  
Tangential Force ◽  
Inlet Guide Vane ◽  
Fluid Forces ◽  
Leakage Flows ◽  
Leakage Path ◽  
Inlet Swirl ◽  
Rotating Impeller ◽  
Rotordynamic Forces

The role played by fluid forces in determining the rotordynamic stability of a centrifugal pump is gaining increasing attention. The present research investigates the contributions to the rotordynamic forces from the discharge-to-suction leakage flows between the front shroud of the rotating impeller and the stationary pump casing. In particular, the dependency of the rotordynamic characteristics of leakage flows on the swirl at the inlet to the leakage path was examined. An inlet guide vane was designed for the experiment so that swirl could be introduced at the leakage flow inlet. The data demonstrates substantial rotordynamic effects and a destabilizing tangential force for small positive whirl ratios; this force decreased with increasing flow rate. The effect of swirl on the rotordynamic forces was found to be destabilizing.

Experimental and Numerical Analysis of Dynamics of the Rotor-Bearing-Seal System

2007 ◽  
Author(s):  
Xiaoyao Shen ◽  
Jianping Jing ◽  
Qimiao Gong
Keyword(s):  
Linear Equations ◽  
Experimental System ◽  
Rotor System ◽  
Force Model ◽  
Nonlinear Phenomena ◽  
Dynamic Force ◽  
Oil Film ◽  
Rotor Bearing ◽  
Linear And Nonlinear ◽  
Analysis Of Dynamics

Linear and nonlinear dynamics and stability of the rotor-bearing-seal system are investigated both theoretically and experimentally. First the system is modeled with the finite element method. The rotordynamic behavior of the journal bearing and the labyrinth seal are represented by eight linearized dynamic force coefficients. An experimental rotor-bearing-seal device is designed and tests are carried out. The experimental system is studied using the developed linear equations. Complex eigenvalues are solved. Corresponding critical speeds and logarithmic decrements to determine the thresholds of instability are calculated. Then the experimental rotor system is simplified as the Jeffcott rotor. The nonlinear oil-film forces are got under the short bearing theory and Muszynska nonlinear seal force model is used. Numerical method is utilized to solve the nonlinear governing equations. Bifurcation diagrams, Poincare´ maps, spectrum plots and rotor orbits are drawn to analyze various nonlinear phenomena and system unstable process. Theoretical results from the linear and nonlinear analysis are in good agreement with results from experiments. Conclusions are drawn and prove that this study will contribute to the further understanding of dynamics and stability of the rotor system with the fluid-induced forces from oil-film bearings and the seals.

scholarly journals The Effect of Inlet Swirl on the Rotordynamic Shroud Forces in a Centrifugal Pump

1993 ◽  
Vol 115 (2) ◽  
pp. 287-293 ◽  
Author(s):  
A. Guinzburg ◽  
C. E. Brennen ◽  
A. J. Acosta ◽  
T. K. Caughey
Keyword(s):  
Centrifugal Pump ◽  
Guide Vane ◽  
Tangential Force ◽  
Inlet Guide Vane ◽  
Fluid Forces ◽  
Leakage Flows ◽  
Leakage Path ◽  
Inlet Swirl ◽  
Rotating Impeller ◽  
Rotordynamic Forces

The role played by fluid forces in determining the rotordynamic stability of a centrifugal pump is gaining increasing attention. The present research investigates the contributions to the rotordynamic forces from the discharge-to-suction leakage flows between the front shroud of the rotating impeller and the stationary pump casing. In particular, the dependency of the rotordynamic characteristics of leakage flows on the swirl at the inlet to the leakage path was examined. An inlet guide vane was designed for the experiment so that swirl could be introduced at the leakage flow inlet. The data demonstrate substantial rotordynamic effects and a destabilizing tangential force for small positive whirl ratios; this force decreased with increasing flow rate. The effect of swirl on the rotordynamic forces was found to be destabilizing.

A Novel Axial Vibration Model of Multistage Pump Rotor System with Dynamic Force of Balance Disc

2019 ◽  
Vol 8 (5) ◽  
pp. 673-683
Author(s):  
Wenjie Zhou ◽  
Yuhua Cao ◽  
Ning Zhang ◽  
Bo Gao ◽  
Ning Qiu ◽  
...  
Keyword(s):  
Rotor System ◽  
Dynamic Force ◽  
Axial Vibration ◽  
Pump Rotor ◽  
Vibration Model ◽  
Multistage Pump

Dynamic analysis of a planar multi-stage centrifugal pump rotor system based on a novel coupled model

2018 ◽  
Vol 434 ◽  
pp. 237-260 ◽  
Author(s):  
Wenjie Zhou ◽  
Ning Qiu ◽  
Leqin Wang ◽  
Bo Gao ◽  
Dong Liu
Keyword(s):  
Dynamic Analysis ◽  
Centrifugal Pump ◽  
Coupled Model ◽  
Rotor System ◽  
Pump Rotor ◽  
Multi Stage

A Cutting Force Model for Face Milling Operation

2013 ◽  
Vol 765-767 ◽  
pp. 378-381 ◽  
Author(s):  
Dong Hong Tang ◽  
Fang Lu
Keyword(s):  
Design Theory ◽  
Orthogonal Design ◽  
Face Milling ◽  
Partial Least Square ◽  
Least Square ◽  
Partial Least Square Regression ◽  
Force Model ◽  
Dynamic Force ◽  
Milling Force ◽  
Milling Force Model

Based on the geometry of the cutter, the dynamic force model of face milling was established. Meanwhile, the fast and effective identification method of milling force model coefficients was provided, which combining the virtues of both orthogonal design theory and partial least-square regression (PLSR) method. Milling experiments have been conducted to verify the proposed face milling force model. Good agreements between the experimental and simulated results were presented.

scholarly journals Research on Steady-State Characteristics of Centrifugal Pump Rotor System with Weak Nonlinear Stiffness

2018 ◽  
Vol 42 (3) ◽  
pp. 87-102 ◽  
Author(s):  
Wenjie Zhou ◽  
Ning Qiu ◽  
Ning Zhang ◽  
Zhounian Lai ◽  
Bo Gao
Keyword(s):  
Steady State ◽  
Centrifugal Pump ◽  
Rotor System ◽  
Nonlinear Stiffness ◽  
Pump Rotor

Research on Grain Impacting Load in Abrasive Flow Machining

2013 ◽  
Vol 797 ◽  
pp. 405-410 ◽  
Author(s):  
Jin Fu Ding ◽  
Ke Hua Zhang ◽  
Yong Chao Xu
Keyword(s):  
Cutting Force ◽  
Process Parameters ◽  
Dynamic Process ◽  
Force Model ◽  
Dynamic Force ◽  
Static Force ◽  
Piston Velocity ◽  
General Process ◽  
Workpiece Surface ◽  
Abrasive Flow Machining

In order to grasp the microcosmic mechanism of abrasive flow machining (AFM), find out the real law of grain cutting workpiece surface, make out a reasonable process parameters and improve the abrasive flow processing efficiency. The process of grain (near to workpiece surface, called as active grains) cutting workpieces material has been analyzed and the cutting force model has been established in present work. Firstly, at the beginning of the present work, the general process of grain cutting, wearing or deburring workpiece surface has been researched. Theoretical analysis shows that the cutting force not only derives from static force, such as abrasive medium viscoelasticity and grain squeezing, but also dynamic force, such as grain impacting load on the workpiece surface. In ordering to prove the dynamic force exists, one or two main dynamic process parameters (such as abrasive viscosity, extrusion pressure, piston velocity) are chosen, dynamic force is most sensitive to the variation of which, meantime, static force is not, and then the effects of main dynamic process parameters on cutting force value have been compared with the effects of others process parameters by several experiments in the present work. The experimental results show that with the same proportion of variation of process parameters, the change in cutting force (mainly axial cutting force) consists with theoretical results very well in some degree.

scholarly journals Experimental Results for the Rotordynamic Characteristics of Leakage Flows in Centrifugal Pumps

1994 ◽  
Vol 116 (1) ◽  
pp. 110-115 ◽  
Author(s):  
A. Guinzburg ◽  
C. E. Brennen ◽  
A. J. Acosta ◽  
T. K. Caughey
Keyword(s):  
Flow Rate ◽  
Tangential Force ◽  
Fluid Structure Interaction ◽  
Centrifugal Pumps ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Fluid Forces ◽  
Leakage Flows ◽  
Clearance Face ◽  
Rotordynamic Forces

In recent years, increasing attention has been given to fluid-structure interaction problems in turbomachines. The present research focuses on just one such fluid-structure interaction problem, namely, the role played by fluid forces in determining the rotordynamic stability and characteristics of a centrifugal pump. The emphasis of this study is to investigate the contributions to the rotordynamic forces from the discharge-to-suction leakage flows between the front shroud of the rotating impeller and the stationary pump casing. An experiment was designed to measure the rotordynamic shroud forces due to simulated leakage flows for different parameters such as flow rate, shroud clearance, face-seal clearance and eccentricity. The data demonstrate substantial rotordynamic effects and a destabilizing tangential force for small positive whirl frequency ratios; this force decreased with increasing flow rate. The rotordynamic forces appear to be inversely proportional to the clearance and change significantly with the flow rate. Two sets of data taken at different eccentricities yielded quite similar nondimensional rotordynamic forces indicating that the experiments lie within the linear regime of eccentricity.

scholarly journals Effective Modes of Axial Balancing of Centrifugal Pump Rotor

2012 ◽  
Vol 39 ◽  
pp. 111-118 ◽  
Author(s):  
P. Kalinichenko ◽  
A. Suprun
Keyword(s):  
Centrifugal Pump ◽  
Pump Rotor
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