Effect of Boundary Conditions, Flow Rate, Slug Length, and Slug Frequency on Slug Flow Induced Vibration in a Pipeline Span

2013 ◽  
Author(s):  
David Jia
Keyword(s):  
Boundary Conditions ◽  
Flow Rate ◽  
Slug Flow ◽  
Flow Induced Vibration

Towards Understanding Two-Phase Flow Induced Vibration of Piping Structure With Flow Restricting Orifices

2017 ◽  
Author(s):  
Olufemi E. Bamidele ◽  
Wael H. Ahmed ◽  
Marwan Hassan
Keyword(s):  
Flow Pattern ◽  
Flow Rate ◽  
Liquid Flow ◽  
Slug Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Liquid Velocity ◽  
Phase Flow ◽  
Flow Induced Vibration ◽  
Two Phase

The current work studies air-water flow through a ½-inch flow restricting orifice installed in a 1-inch pipe. Investigation of two phase flow downstream the orifice and its effects on vibration of the piping structure have been carried out. Several flow regimes from bubbly to stratified-wavy flow have been analyzed to evaluate the effects of flow pattern, phase redistribution, bubble frequency, and liquid flow rate on the vibration of the structure. The liquid velocity fields have been obtained using Particle Image Velocimetry (PIV) along with post processing algorithm for phase discrimination. Proximity sensors have been used to capture the pipe response in two orthogonal directions. Also, a capacitance sensor was used to measure the two-phase void fraction. The results show that the magnitude and nature of vibrations of the piping structure is largely affected by the frequency and size of the bubbles upstream, vortex creation by pressure fluctuation downstream, liquid flow rate, and the flow pattern upstream. Slug flow and stratified flow patterns induced significant vibrations in the examined structure. The location of the transition region of slug flow on flow pattern maps, play important role in the dynamic response of the structure to the flow.

Study of fluid flow through a channel deformed by piezoelement

2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Contact Surface ◽  
Piezoelectric Element ◽  
Neumann Boundary ◽  
Differential Pressure ◽  
Physical Parameters ◽  
Flow Through

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.

scholarly journals Development of Hybrid Airlift-Jet Pump with Its Performance Analysis

2018 ◽  
Vol 8 (9) ◽  
pp. 1413 ◽  
Author(s):  
Dan Yao ◽  
Kwongi Lee ◽  
Minho Ha ◽  
Cheolung Cheong ◽  
Inhiug Lee
Keyword(s):  
Boundary Conditions ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Stokes Equations ◽  
Flow Characteristics ◽  
Operating Conditions ◽  
Navier Stokes ◽  
Jet Pump ◽  
Two Phase

A new pump, called the hybrid airlift-jet pump, is developed by reinforcing the advantages and minimizing the demerits of airlift and jet pumps. First, a basic design of the hybrid airlift-jet pump is schematically presented. Subsequently, its performance characteristics are numerically investigated by varying the operating conditions of the airlift and jet parts in the hybrid pump. The compressible unsteady Reynolds-averaged Navier-Stokes equations, combined with the homogeneous mixture model for multiphase flow, are used as the governing equations for the two-phase flow in the hybrid pump. The pressure-based methods combined with the Pressure-Implicit with Splitting of Operators (PISO) algorithm are used as the computational fluid dynamics techniques. The validity of the present numerical methods is confirmed by comparing the predicted mass flow rate with the measured ones. In total, 18 simulation cases that are designed to represent the various operating conditions of the hybrid pump are investigated: eight of these cases belong to the operating conditions of only the jet part with different air and water inlet boundary conditions, and the remaining ten cases belong to the operating conditions of both the airlift and jet parts with different air and water inlet boundary conditions. The mass flow rate and the efficiency are compared for each case. For further investigation into the detailed flow characteristics, the pressure and velocity distributions of the mixture in a primary pipe are compared. Furthermore, a periodic fluctuation of the water flow in the mass flow rate is found and analyzed. Our results show that the performance of the jet or airlift pump can be enhanced by combining the operating principles of two pumps into the hybrid airlift-jet pump, newly proposed in the present study.

Towards Multiphase Periodic Boundary Conditions with Flow Rate Constraint

2011 ◽  
Author(s):  
Robert Sawko ◽  
Chris P. Thompson ◽  
Theodore E. Simos ◽  
George Psihoyios ◽  
Ch. Tsitouras ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Flow Rate ◽  
Periodic Boundary ◽  
Periodic Boundary Conditions

A Hybrid Method for Fan Simulations in Full Vehicle Thermal Analyses

2020 ◽  
Author(s):  
Zhilei Wu ◽  
Michael Blatnik ◽  
Eamonn Kress ◽  
Lester Deleon
Keyword(s):  
Boundary Conditions ◽  
Rigid Body ◽  
Mass Flow Rate ◽  
Flow Rate ◽  
Transient Simulation ◽  
Body Motion ◽  
Thermal Flow ◽  
Full Vehicle ◽  
Steady Simulation ◽  
Thermal Wake

Abstract In full vehicle thermal flow analyses, the most often used procedure to simulate fluid motions driven by the cooling fan is the Moving Reference Frame (MRF) method. In the MRF approach, the fan is fixed in space and the fan rotation is modeled using grid fluxes. This method is widely used because it provides a fast and effective means of simulating fans. However, the MRF method does not always accurately predict the thermal wake and the mass flow rate through the fan, which causes errors in predicted temperatures on the parts downstream of the fan. Another method for fan simulation is the Rigid Body Motion (RBM) method in which the fan rotates in time. The RBM method models the fan motions directly, thus it can accurately predict the mass flow rate and thermal wake. However, an RBM simulation is transient and needs a time-average to obtain statistically steady-state results. The RBM method requires a significant amount of CPU resources and simulation time, which prevents it from being widely used in industry. In the current work, a Hybrid Rigid Body Motion (HRBM) method is developed and validated. The HRBM method splits the full vehicle thermal simulation into two simulations, and then couples them at the interface. The first simulation is transient, utilizes the RBM method for the fan, and only models the fan regions. The second simulation is steady, which models the full vehicle except the fan regions. The solution from the transient simulation is time-averaged on the exchange interface and used as boundary conditions for the steady simulation. Conversely, the solution for the steady simulation is used as boundary conditions for the transient simulation at the exchange interface. Due to the slight differences resulting from time-averaging, there is a mismatch in the physical quantities at the exchange interface. This causes stability issues which prevent the coupled simulations from converging. Special techniques have been used in this work to stabilize the solution at the interface, which ensured the convergence of the coupled simulations. The HRBM method greatly improves the accuracy of the full vehicle thermal flow simulation compared to using the MRF method. The thermal wake that results from using HRBM to model the fan is very similar to that produced by RBM, but HRBM utilizes ∼20–30% of the simulation resources required by RBM to achieve convergence.

Joint and Cross Acceptances for Cross-Flow-Induced Vibration—Part II: Charts and Applications

2000 ◽  
Vol 122 (3) ◽  
pp. 355-361 ◽  
Author(s):  
M. K. Au-Yang
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Boundary Conditions ◽  
Computer Program ◽  
Cross Flow ◽  
Flow Induced Vibration ◽  
Modal Coupling ◽  
Analysis Computer ◽  
Flow Turbulence ◽  
Analysis Computer Program

Using closed-form and finite element solutions derived in Part I of this paper together with a standard commercial finite element structural-analysis computer program, the joint and cross acceptances for tubes and beams with different boundary conditions are calculated as a function of the correlation length up to 10 times the length of the structures. The results are presented in the form of charts. Steps are given to show how to use these charts together with standard commercial finite-element structural-analysis computer programs to estimate the responses of single and multi-span tubes and beams to cross-flow turbulence-induced vibration. The importance of cross-modal coupling for multi-supported beams is investigated. Examples are given. [S0094-9930(00)03303-5]

Analysis of the Full Flow Field of Torque Converter

2012 ◽  
Vol 468-471 ◽  
pp. 674-677 ◽  
Author(s):  
Yu Long Lei ◽  
Chang Wang ◽  
Zheng Jie Liu ◽  
Xing Zhong Li
Keyword(s):  
Flow Field ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Flow Model ◽  
Three Dimensional ◽  
Calculated Data ◽  
Torque Converter ◽  
Three Dimensional Flow ◽  
Sliding Mesh ◽  
Mesh Method

Establish the full three-dimensional flow model of the torque converter, proper mesh the model, select the appropriate boundary conditions, and use the sliding mesh method to deal with the interactions of the impeller, turbine, and reactor in different rotation speeds. Analysis the flow rate, pressure, and the loss of full flow field passage of the torque converter, elaborate the formation mechanism of the flow field, agreement with the experimental date compare to the calculated data, more accurate than the traditional single passage model compare to the full passage model, provide the direction of design optimization of the torque converter.

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