1

Slug flow and fluid-structure interaction in industrial pipe

systems

Qingzhi Hou

2

Overview

Introduction

Two-phase flows

Test problems

Mathematical models

Fluid-structure interaction

Conclusions

3

Industrial problemsMoving pipes

4

Broken pipes

5

Two-phase flowsTwo-phase flow regimes Butterworth &

Hewitt 1977

6

Test problems Bozkus and Wiggert laboratory set up (1997)

water

7

Measured pressures at elbow

Pressure1

Pressure2

8

Different flow regions

9

Delft experiment (European project)

pipe filling and emptying

L = 300 mD = 0.25 m

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Test setup

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Observed two-phase flow

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Delft water-hammer accident

7.03 7.031 7.032 7.033 7.034 7.035 7.036 7.037 7.038 7.039 7.04

x 106

-1

0

1

2

3

4

5

Time (ms)

Pre

ssur

e (b

ar)

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1D-models Single phase Water hammer

Pipe vibration

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

Time (s)

Pre

ssur

e (M

Pa)

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Moving slug

SlugHold-up Downstream Gas

Upstream Gas

Slug flow – 1D model

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Slug impact at the elbow - 1D model

Dynamic pressure

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Italian experiment (slug flow in vertical pipe)

Filling through orifice (Giuseppe D.M 2008)

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Smoothed particle hydrodynamics (SPH)• Lucy (1977) and Monaghan (1977)• Advantages: easy to deal with free surfaces, moving boundaries, high velocity impacts, explosions and large deformations. • Kernel approximation Particle approximation

3D-models

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Lagrangian form

• Continuity equation

• Momentum equation

• Energy equation

Conservation laws

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Summation density

Continuity density

SPH Mass

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SPH Momentum

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SPH Energy

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Fluid-structure interaction (FSI)

• Forces on pipes and anchors

• Vibration of pipes

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• Basic modes of vibrations• Coupling mechanisms

FSI

to be included in model

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Summary

Performed tasks Literature review Delft experiment 1D modeling FSI in frequency domain

Coming half year Data analysis of experiment 1D modeling (two phase flow) SPH modeling

Final goal Simulation tool for filling of pipelines

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Bozkus Z, Wiggert D.C (1997). Liquid slug motion in a voided line. Journal of Fluids and Structures, 11, 947-963.

Butterworth D, Hewitt G. F (1977). Two-Phase Flow and Heat Transfer. Oxford: Oxford University Press.

Doyle J.F (1997). Wave Propagation in Structures. New York: Springer Press.

Giuseppe D.M, Nicola F, and Maurizio G (2008). Transient Flow Caused by Air Expulsion through an Orifice. Journal of Hydraulic Engineering, 134(9), 1395-1399.

Liu G.R, Liu M.B (2003). Smoothed Particle Hydrodynamics: A Meshfree Particle Method. Singapore: World Scientific Publishing Co Pte Ltd.

Lucy L.B (1977). Numerical approach to test the fission hypothesis. Astronomical Journal, 82: 1013-1024.

Gingold R.A, Monaghan J.J (1977). Smoothed particle hydrodynamics: theory and application to non-spherical stars. Royal Astronomical Society, 181: 375-389.

References