Wyniki wyszukiwania - BazTech

1

Effect of Pipe Bends on the Low-Frequency Torsional Guided Wave Propagation

Wu Wenjun, Wang Junhua

Archives of Acoustics

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2020

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Vol. 45, No. 3

385--391

EN

Wave motion in pipe bends is much more complicated than that in straight pipes, thereby changing considerably the propagation characteristics of guided waves in pipes with bends. Therefore, a better understanding of how guided waves propagate in pipe bends is essential for inspecting pipelines with bends. The interaction between a pipe bend and the most used non-dispersive torsional mode at low frequency in a small-bore pipe is studied in this paper. Experiments are conducted on a magnetostrictive system, and it is observed that T(0,1) bend reflections and mode conversions from T(0,1) to F(1,1) and F(2,1) occur in the pipe bend. The magnitude of the T(0,1) bend reflections increases with increasing propagation distance and excitation frequency. The amplitude of the mode-converted signals also increases with increasing propagation distance, but it decreases with increasing excitation frequency. Because of their longer bent path, the test signals for a pipe bend with a bending angle of 180º are much more complicated than those for one with a bending angle of 90º. Therefore, it is even more difficult to scan a bent pipe with a large bending angle. The present findings provide some insights into how guided waves behave in pipe bends, and they generalize the application of guided-wave inspection in pipelines.

2

Multiphase flow mixture in 180[degrees] pipe bends

Pietrzak M., Witczak S.

Chemical and Process Engineering

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2013

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Vol. 34, nr 2

227--239

EN

This paper presents the results of research regarding measurements of the values of pressure drops during horizontal flow of gas-liquid and gas-liquid-liquid mixture through 180o pipe bends. The conducted insightful analysis and assessment during multi-phase flow in pipe bends has enabled to develop a new method for determination of their values. This new method for determining pressure drops ensures higher precision of calculation in comparison to other methods presented in literature and can be applied for calculation of these parameters during multi-phase flows in pipe bends with various geometries.

3

Hydrodynamika poziomego przepływu dwufazowego ciecz - ciecz w kanałach zakrzywionych

Pietrzak M., Witczak S.

Inżynieria i Aparatura Chemiczna

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2012

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Nr 6

366-367

PL

W pracy przedstawiono wyniki badań dotyczących struktur przepływu oraz wartości udziałów objętościowych faz przy przepływie mieszaniny dwufazowej woda - olej przez poziome łuki rurowe. W wyniku przeprowadzonych badań wyróżniono kilka charakterystycznych form przepływu dwufazowego ciecz - ciecz, opracowano mapę przepływu dwufazowego ciecz - ciecz oraz zależność określającą sposób wyznaczania wartości udziałów objętościowych faz przy poziomym przepływie dwufazowym ciecz - ciecz w łukach rurowych.

EN

Test results of hydrodynamics of oil-water two-phase flow in pipe bends are presented in the paper. As a result of the studies types of flow patterns formed in the pipe tested and values of volume fractions of phases were determined. The relationship for determining phase volume fractions in liquid-liquid flow in horizontal pipe bends is proposed.