Numerical Study on Taylor Bubble Rising in Pipes
1
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
Slug flow is the most common multi-phase flow encountered in oil and gas industry. In this study, the hydrodynamic features of flow in pipes investigated numerically using computational fluid dynamic (CFD) simulations for the effect of slug flow on the vertical and bent pipeline. The compressible Reynold averaged Navier-Stokes (RANS) equation was used as the governing equation, with the volume of fluid (VOF) method to capture the outline of the bubble in a pipeline. The simulations were tested for the grid and time step convergence, and validated with the experimental and theoretical results for the main hydrodynamic characteristics of the Taylor bubble, i.e., bubble shape, terminal velocity of bubble, and the liquid film velocity. The slug flow was simulated with various air and water injection velocities in the pipeline. The simulations revealed the effect of slug flow as the pressure occurring in the wall of the pipeline. The peak pressure and pressure oscillations were observed, and those magnitudes and trends were compared with the change in air and water injection velocities. The mechanism of the peak pressures was studied in relation with the change in bubble length, and the maximum peak pressures were investigated for the different positions and velocities of the air and water in the pipeline. The pressure oscillations were investigated in comparison with the bubble length in the pipe and the oscillation was provided with the application of damping. The pressures were compared with the case of a bent pipe, and a 1.5 times higher pressures was observed due to the compression of the bubbles at the corner of the bent. These findings can be used as a basic data for further studies and designs on pipeline systems with multi-phase flow.
Abstract
Slug flow is the most common multi-phase flow encountered in oil and gas industry. In this study, the hydrodynamic features of flow in pipes investigated numerically using computational fluid dynamic (CFD) simulations for the effect of slug flow on the vertical and bent pipeline. The compressible Reynold averaged Navier-Stokes (RANS) equation was used as the governing equation, with the volume of fluid (VOF) method to capture the outline of the bubble in a pipeline. The simulations were tested for the grid and time step convergence, and validated with the experimental and theoretical results for the main hydrodynamic characteristics of the Taylor bubble, i.e., bubble shape, terminal velocity of bubble, and the liquid film velocity. The slug flow was simulated with various air and water injection velocities in the pipeline. The simulations revealed the effect of slug flow as the pressure occurring in the wall of the pipeline. The peak pressure and pressure oscillations were observed, and those magnitudes and trends were compared with the change in air and water injection velocities. The mechanism of the peak pressures was studied in relation with the change in bubble length, and the maximum peak pressures were investigated for the different positions and velocities of the air and water in the pipeline. The pressure oscillations were investigated in comparison with the bubble length in the pipe and the oscillation was provided with the application of damping. The pressures were compared with the case of a bent pipe, and a 1.5 times higher pressures was observed due to the compression of the bubbles at the corner of the bent. These findings can be used as a basic data for further studies and designs on pipeline systems with multi-phase flow.
참고문헌 (27)
- J.D.P. Araújo, "Wide-ranging survey on the laminar flow of individual Taylor bubbles rising through stagnant Newtonian liquids", International Journal of Multiphase Flow, 43, pp.131~148 (2012), Elsevier BV[DOI]
- Bøckmann, A., "An Experimental and Computational Development of a Benchmark Solution for the Validation of Numerical Wave Tanks", Proceedings of the ASME 2014 33rd International Conference Ocean, Offshore and Arctic Engineering, 2 (2014)
- Biberg, D., "Mathematical Models for Two-phase Stratified Pipe Flow", Ph. D, pp.2005
- Brennen, C. E., "Fundamentals of Multiphase Flow" (2005), Cambridge University Press
- R. A. S. Brown, "The mechanics of large gas bubbles in tubes: I. Bubble velocities in stagnant liquids", The Canadian Journal of Chemical Engineering, 43(5), pp.217~223 (1965), Wiley[DOI]
- J.D. Bugg, "A numerical model of Taylor bubbles rising through stagnant liquids in vertical tubes", International Journal of Multiphase Flow, 24(2), pp.271~281 (1998), Elsevier BV[DOI]
- Star-CCM+ 10.04 User’s Manual, "CD-Adapco", ~ (2015)
- A. Clarke, "A numerical model of slug flow in vertical tubes", Computers & Fluids, 26(4), pp.395~415 (1997), Elsevier BV[DOI]
- Davies, R.M., "The mechanics of large bubbles rising through extended liquids and through liquids in tubes", Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 200(1062), pp.375~390 (1950), The Royal Society[DOI]
- D. T. Dumitrescu, "Strömung an einer Luftblase im senkrechten Rohr", ZAMM - Zeitschrift für Angewandte Mathematik und Mechanik, 23(3), pp.139~149 (1943), Wiley[DOI]
- Hirsch, C., "Numerical Computation of Internal and External Flows (Volume 1: Fundamentals of Numerical Discretization)" (1988), John Wiley and Sons
- Hirt, C. W., "Volume of Fluid (VOF) Method for the Dynamics of Free Boundaries", Journal of Computational Physics, 391, pp.201~225 (1981)
- Kang, C. W., "Numerical Study of a Taylor Bubble Rising in Stagnant Liquids", Physical Review E, 81(6), pp.066308~ (2010)
- M. Kawaji, "Investigation of flow structures in vertical slug flow", Nuclear Engineering and Design, 175(1-2), pp.37~48 (1997), Elsevier BV[DOI]
- E.Z. Massoud, "Numerical study of an individual Taylor bubble rising through stagnant liquids under laminar flow regime", Ocean Engineering, 162, pp.117~137 (2018), Elsevier BV[DOI]
- L. Ó Náraigh, "Interfacial instability in turbulent flow over a liquid film in a channel", International Journal of Multiphase Flow, 37(7), pp.812~830 (2011), Elsevier BV[DOI]
- N.V. Ndinisa, "Computational Fluid Dynamics Simulations of Taylor Bubbles in Tubular Membranes", Chemical Engineering Research and Design, 83(1), pp.40~49 (2005), Elsevier BV[DOI]
- Nicklin, D. J., "Two-phase Flow in Vertical Tubes", Transactions of the Institution of Chemical Engineers, 40(1), pp.61~68 (1962)
- S. Nogueira, "Flow patterns in the wake of a Taylor bubble rising through vertical columns of stagnant and flowing Newtonian liquids: An experimental study", Chemical Engineering Science, 61(22), pp.7199~7212 (2006), Elsevier BV[DOI]
- S. Polonsky, "Averaged and time-dependent characteristics of the motion of an elongated bubble in a vertical pipe", International Journal of Multiphase Flow, 25(5), pp.795~812 (1999), Elsevier BV[DOI]
- Roache, P. J., "Verication and Validation in Computational Science and Engineering" (1998), Hermosa Publishers
- 서성욱, "CFD의 불확실성 해석에 대한 고찰 및 소스 공개코드를 이용한 선박저항성능에의 적용", 대한조선학회 논문집, 53(4), pp.329~335 (2016), 대한조선학회
- Fred Stern, "Quantitative V&V of CFD simulations and certification of CFD codes", International Journal for Numerical Methods in Fluids, 50(11), pp.1335~1355 (2006), Wiley[DOI]
- Taha Taha, "CFD modelling of slug flow in vertical tubes", Chemical Engineering Science, 61(2), pp.676~687 (2006), Elsevier BV[DOI]
- R van Hout, "Experimental investigation of the velocity field induced by a Taylor bubble rising in stagnant water", International Journal of Multiphase Flow, 28(4), pp.579~596 (2002), Elsevier BV[DOI]
- Kai Yan, "Hydrodynamic and mass transfer characteristics of slug flow in a vertical pipe with and without dispersed small bubbles", International Journal of Multiphase Flow, 37(4), pp.299~325 (2011), Elsevier BV[DOI]
- Donghong Zheng, "An investigation on near wall transport characteristics in an adiabatic upward gas–liquid two-phase slug flow", Heat and Mass Transfer, 43(10), pp.1019~1036 (2007), Springer Science and Business Media LLC[DOI]