scholarly journals Study on Vibration of Reciprocating Pump Pipelines Based on Pressure Pulsation Theory

2017 ◽  
Author(s):  
Hongfang Lu
Keyword(s):  
Numerical Simulation ◽  
Vibration Amplitude ◽  
Pressure Pulsation ◽  
Fluid Pressure ◽  
Simulation Method ◽  
Pipeline System ◽  
Beam Model ◽  
Pipe Failure ◽  
Periodic Movement ◽  
Reciprocating Pump

Due to the periodic movement of the piston in the reciprocating pump, the fluid will cause pressure pulsation, and the vibration of the pipeline will lead to instrument distortion, pipe failure and equipment damage. Therefore, it is necessary to study the vibration phenomena of the reciprocating pump pipeline based on the pressure pulsation theory. This paper starts from the reciprocating pump pipe pressure pulsation caused by fluid, pressure pulsation in the pipeline and the excited force is calculated under the action of the reciprocating pump. Then, the numerical simulation model is established based on the pipe beam model, and the rationality of the numerical simulation method is verified by the indoor experiment. Finally, a case study is taken as an example to analyze the vibration law of the pipeline system, and proposed the stress reduction and vibration reduction measures. The main conclusions are drawn from the analysis: (1) Excited force is produced in the bend or tee joint, and it can also influence the straight pipe in different levels; (2) In this pipeline system, the pump discharge pipe has a larger vibration amplitude and lower natural frequency; (3) The vibration amplitude increases with the pipe thermal stress, and when the oil temperature is higher than 85°C, it had a greater influence on the vertical vibration amplitude of the pipe.

scholarly journals Propagation Characteristics of Pressure Pulsation in Hydraulic Hose

2021 ◽  
Vol 2095 (1) ◽  
pp. 012088
Author(s):  
Yuzhen Meng ◽  
Lei Han ◽  
Wenkui Zhao ◽  
Lishan Zhang
Keyword(s):  
Numerical Simulation ◽  
Pressure Pulsation ◽  
Fluid Pressure ◽  
Pipeline System ◽  
Hydraulic Systems ◽  
Coupling Vibration ◽  
Hydraulic Oil ◽  
Vibration Model ◽  
Propagation Law ◽  
Pipe Bending

Abstract Most modern aircraft hydraulic systems use variable plunger pumps. The pulsating flow output is its inherent characteristic. The resulting pressure pulsation often causes serious damage to the energy pipeline system and endangers the lives of the occupants. This paper studies the propagation law of hydraulic oil in hydraulic hoses, fully considers the coupling vibration of hydraulic oil high-pressure fluid and flexible solids of the hose, establishes a fluid-solid coupling vibration model of hydraulic hoses, and uses ANSYS for numerical simulation to study different frequencies and pipe bending. Using ANSYS for numerical simulation to study the influence of different frequencies and pipe bending radii on the amplitude of fluid pressure pulsation, after comparative analysis, the law of fluid pressure pulsation propagation in hydraulic hoses is obtained.

The Numerical Simulation of Gas-Liquid-Solid Three-Phase Flow in the Disc Pump

2011 ◽  
Vol 320 ◽  
pp. 434-440 ◽  
Author(s):  
Bin Li ◽  
Hao Qi
Keyword(s):  
Numerical Simulation ◽  
Solid Phase ◽  
Phase Particle ◽  
Fluid Pressure ◽  
Simulation Method ◽  
Phase Flow ◽  
Pump Impeller ◽  
Actual Application ◽  
Three Phase ◽  
Three Phase Flow

In this paper, the flow law of gas-liquid-solid three-phase flow was studied in the disc pump internal, established a set of numerical simulation method that calculated multiphase flows of disc pump internal. Finally the structure of the disk pump impeller was improved, and designed a new disc pump with multiple-blade structure, through numerical simulation calculation for the gas-liquid-solid three-phase flow of the disc pump internal, mastered change rule of fluid pressure and speed in disk pump internal, obtained relation curves between the different solid phase particle concentration with different gas phase concentration and the head with the efficiency of the pump. The head of the new disc pump was significantly improved by analyzing the disc pump head curve and the actual application.

Nonlinear dynamic modeling and fluid–mechanism interaction analysis of reciprocating pump–pipeline system

2020 ◽  
pp. 095965182096510
Author(s):  
Zhenjie Gu ◽  
Changqing Bai ◽  
Hongyan Zhang
Keyword(s):  
Dynamic Modeling ◽  
Dynamic Characteristics ◽  
Pressure Pulsation ◽  
Control Valve ◽  
Pipeline System ◽  
Flow Control Valve ◽  
Proposed Model ◽  
Reciprocating Pump ◽  
Nonlinear Dynamic Modeling ◽  
Crank Mechanism

The dynamic characteristics of reciprocating pump–pipeline system are directly affected by the fluid–mechanism dynamic interaction related to the slider-crank mechanism, valves and pipes conveying fluid. In this article, the fluid–mechanism interaction and nonlinearities involved in the kinetic of slider-crank mechanism, the motions of pump valves and the dynamic transmission in pipeline are explored for the nonlinear dynamic modeling of reciprocating pump–pipeline interaction systems. The nonlinear fluid–mechanism coupling model and corresponding analysis procedure are presented for investigating the system dynamic characteristics at all operating conditions. An experiment platform consisting of a simplex plunger reciprocating pump and suction and discharge pipes with a flow control valve is established to validate the proposed model. By the comparisons of pressure pulsations under multi-working conditions, the results obtained from the proposed model show good agreement with the test data. The dynamic characteristic of pump, as well as the effects of interaction and nonlinearity on the flow pulsation, are studied with the proposed model. It is found that nonlinear factors such as joint clearance and nonlinear spring stiffness are of great importance to the lag characteristics of pump valves and the pressure pulsation of pump–pipe system. The amplitudes of pressure pulsation increase with the decrease of control valve opening nonlinearly, and the effect of flow control valve becomes significant when the opening is less than 40%.

scholarly journals Numerical analysis of multi-scale pressure pulsation on the energy accumulation for submarine-based tracking and pointing systems

2021 ◽  
pp. 002029402198974
Author(s):  
Liu Zongkai ◽  
Tang Zhaolie
Keyword(s):  
Numerical Simulation ◽  
Pressure Pulsation ◽  
Transfer Functions ◽  
Tracking System ◽  
Simulation Method ◽  
Optical Tracking ◽  
Small Scale ◽  
Control Effect ◽  
Amplitude Error ◽  
Multi Scale

One of the main goals of submarine designers and researchers is to estimate the influence of submarine fluid dynamics for submarine-based optical tracking and pointing systems. In this study, firstly, based on the basic flow governing equation and hierarchical grids, the numerical simulation method of DNS (direct numerical simulation) is adopted to simulate the seawater flow around the submarine at 6° yaw angle and 107 Reynolds number. Secondly, the transformation equations from the earth coordinate system to the optical axis system have been deduced and the ultimate influence of pressure torques on the tracking system is studied. Transfer functions of the coarse channel direct current (DC) torque motor and fine channel fast steering mirror (FSM) also have been modeled and deduced. On this basis, the time domain step responses of both subsystems are analyzed by MATLAB Simulink. Finally, performance analyses have been deduced by comparing the error variation and vortices evolution. It revealed that the frequency characteristics of multi-scale pressure pulsation mainly depended on the lengths of submarine hull or its appendage, as well as the fluid dissipation and random interaction. In general, the coarse channel appears a good compensation performance at low frequency and large amplitude error that caused by the middle-scale pressure pulsation. Contrarily, the FSM fine channel exerts an excellent control effect for higher frequency and small amplitude error caused by small-scale pressure pulsations.

scholarly journals An Approach to Determine Optimal Bow Configuration of Polar Ships under Combined Ice and Calm-Water Conditions

2021 ◽  
Vol 9 (6) ◽  
pp. 680
Author(s):  
Hui Li ◽  
Yan Feng ◽  
Muk Chen Ong ◽  
Xin Zhao ◽  
Li Zhou
Keyword(s):  
Numerical Simulation ◽  
Water Resistance ◽  
Numerical Technique ◽  
Experimental Studies ◽  
Resistance Index ◽  
Simulation Method ◽  
Present Approach ◽  
Calm Water ◽  
Level Ice ◽  
Ice Resistance

Selecting an optimal bow configuration is critical to the preliminary design of polar ships. This paper proposes an approach to determine the optimal bow of polar ships based on present numerical simulation and available published experimental studies. Unlike conventional methods, the present approach integrates both ice resistance and calm-water resistance with the navigating time. A numerical simulation method of an icebreaking vessel going straight ahead in level ice is developed using SPH (smoothed particle hydrodynamics) numerical technique of LS-DYNA. The present numerical results for the ice resistance in level ice are in satisfactory agreement with the available published experimental data. The bow configurations with superior icebreaking capability are obtained by analyzing the sensitivities due to the buttock angle γ, the frame angle β and the waterline angle α. The calm-water resistance is calculated using FVM (finite volume method). Finally, an overall resistance index devised from the ship resistance in ice/water weighted by their corresponding weighted navigation time is proposed. The present approach can be used for evaluating the integrated resistance performance of the polar ships operating in both a water route and ice route.

scholarly journals Experiment and simulation about the effect of wear-ring abrasion on the performance of a marine centrifugal pump

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199811
Author(s):  
Wu Xianfang ◽  
Du Xinlai ◽  
Tan Minggao ◽  
Liu Houlin
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Vibration Velocity ◽  
Test Results ◽  
Obvious Effect ◽  
Performance Change ◽  
Pump Test ◽  
Simulation Results ◽  
Axis Passing

The wear-ring abrasion can cause performance degradation of the marine centrifugal pump. In order to study the effect of front and back wear-ring clearance on a pump, test and numerical simulation were used to investigate the performance change of a pump. The test results show that the head and efficiency of pump decrease by 3.56% and 9.62% respectively at 1.0 Qd due to the wear-ring abrasion. Under 1.0 Qd, with the increase of the front wear-ring the vibration velocity at pump foot increases from 0.4 mm/s to 1.0 mm/s. The axis passing frequency (APF) at the measuring points increases significantly and there appears new characteristic frequency of 3APF and 4APF. The numerical simulation results show that the front wear-ring abrasion affects the flow at the inlet of the front chamber of the pump and impeller passage. And the back wear-ring abrasion has obvious effect on the flow in the back chamber of the pump and impeller passage, while the multi-malfunction of the front wear-ring abrasion and back wear-ring abrasion has the most obvious effect on the flow velocity and flow stability inside pump. The pressure pulsation at Blade Passing Frequency (BPF) of the three schemes all decrease with the increase of the clearance.

A numerical simulation method for molten material behavior in nuclear reactors

2017 ◽  
Vol 322 ◽  
pp. 301-312 ◽  
Author(s):  
Susumu Yamashita ◽  
Takuya Ina ◽  
Yasuhiro Idomura ◽  
Hiroyuki Yoshida
Keyword(s):  
Numerical Simulation ◽  
Nuclear Reactors ◽  
Simulation Method ◽  
Material Behavior ◽  
Molten Material ◽  
Numerical Simulation Method
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