Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Pressure Distribution over Tube Surfaces of Tube Bundle Subjected to Two-Phase Cross-Flow

이상 유동에 놓인 관군의 표면에 작용하는 압력 분포

  • Sim, Woo Gun (Dept. of Mechanical Engineering, Hannam Univ.)
  • 심우건 (한남대학교 기계공학과)
  • Received : 2011.08.22
  • Accepted : 2012.10.08
  • Published : 2013.01.01
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Abstract

Two-phase vapor-liquid flows exist in many shell and tube heat exchangers such as condensers, evaporators, and nuclear steam generators. To understand the fluid dynamic forces acting on a structure subjected to a two-phase flow, it is essential to obtain detailed information about the characteristics of a two-phase flow. The characteristics of a two-phase flow and the flow parameters were introduced, and then, an experiment was performed to evaluate the pressure loss in the tube bundles and the fluid-dynamic force acting on the cylinder owing to the pressure distribution. A two-phase flow was pre-mixed at the entrance of the test section, and the experiments were undertaken using a normal triangular array of cylinders subjected to a two-phase cross-flow. The pressure loss along the flow direction in the tube bundles was measured to calculate the two-phase friction multiplier, and the multiplier was compared with the analytical value. Furthermore, the circular distributions of the pressure on the cylinders were measured. Based on the distribution and the fundamental theory of two-phase flow, the effects of the void fraction and mass flux per unit area on the pressure coefficient and the drag coefficient were evaluated. The drag coefficient was calculated by integrating the measured pressure on the tube by a numerical method. It was found that for low mass fluxes, the measured two-phase friction multipliers agree well with the analytical results, and good agreement for the effect of the void fraction on the drag coefficients, as calculated by the measured pressure distributions, is shown qualitatively, as compared to the existing experimental results.

이상 횡 유동은 응축기, 증발기와 원자로 증기발생기와 같은 쉘과 튜브의 열 교환기에서 볼 수 있다. 이상 유동장에 놓인 구조물에 작용하는 수동력을 이해하기 위해서는 이상유동의 특성을 이해하는 것이 중요하다. 이상 유동의 유동특성과 유동변수를 소개하고 관군에서의 압력손실과 실린더에 작용하는 압력분포에 의한 수동력을 평가하기 위한 실험을 수행하였다, 실험부 입구에서 이상유동은 혼합되었으며 실험은 횡 방향 이상 유동장에 놓인 정규 삼각형 배열을 갖는 관군을 사용하여 수행하였다. 관군에서의 흐름방향 압력손실을 측정하여 이상유동의 마찰승수를 계산하고 이론적 결과와 비교하였다. 또한 특정 실린더에 작용하는 원주 방향 압력 분포의 측정결과와 이상유동의 기초이론에 근거하여 압력손실계수의 분포 및 항력계수에 미치는 체적건도와 단위면적당 질량유량의 효과를 평가하였다. 튜브 표면에 작용하는 측정된 압력을 수치해석방법으로 적분하여 항력계수를 계산하였다. 작은 질량 유량의 경우에 측정된 마찰 승수는 기존의 이론 결과와 잘 일치하며 압력분포에 의한 항력계수에 작용하는 기공률의 영향은 기존의 실험결과와 정성적으로 유사한 경향을 보이고 있다.

Keywords

References

  1. Blevins, R.D., 1990, "Flow-Induced Vibration," Second Edition, Van Nosrtrand, New York
  2. Fritz, R.J., 1972, "The Effect of Liquids on the Dynamic Motions of Immersed Solids," ASME Journal of Engineering for Industry, 94, pp.167-173. https://doi.org/10.1115/1.3428107
  3. Pettigrew, M. J., Taylor, C.E., 1991, "Fluidelastic Instability of Heat Exchanger Tube Bundles; Review and Design Recommendations," ASME Journal of Pressure Vessel Technology, Vol. 113, pp. 242-256. https://doi.org/10.1115/1.2928752
  4. Price, S.J., 1995, "A Review of Theoretical Models for Fluidelastic Instability of Cylinder Arrays in Cross- Flow," Journal of Fluids and Structure, 9, pp. 463-518. https://doi.org/10.1006/jfls.1995.1028
  5. Carlucci, L.N., 1980, "Damping and Hydrodynamic Mass of a Cylinder in Simulated Two-Phase Flow," Journal of Mechanical Design, 102, pp597-602. https://doi.org/10.1115/1.3254791
  6. Carlucci, L.N. and Brown, J.D., 1983, "Experimental Studies of Damping and Hydrodynamic Mass of a Cylinder in Confined Two-Phase Flow," Journal of Vibration, Acoustics, Stress, and Reliability in Design, 105, pp.83-89. https://doi.org/10.1115/1.3269073
  7. Pettigrew, M.J., Taylor, C.E. and Kim, B.S., 1989a, "Vibration of Tube Bundles in Two Phase Cross Flow; Part 1 - Hydrodynamic Mass and Damping," ASME Journal of Pressure Vessel Technology, 111, pp. 466-477. https://doi.org/10.1115/1.3265705
  8. Pettigrew, M.J., Tromp, J.H., Taylor, C.E. and Kim, B.S., 1989b, "Vibration of Tube Bundles in Two Phase Cross Flow; Part 2 - Fluid-Elastic Instability," ASME Journal of Pressure Vessel Technology, 111, pp. 478-487. https://doi.org/10.1115/1.3265706
  9. Pettigrew, M.J. and Taylor, C.E., 2003, "Vibration Analysis of Shell-and-Tube Heat Exchangers; An Overview- Part 2: Vibration Response, Fretting-Wear, Guidelines," Journal of Fluids and Structure, 18, pp. 485-500. https://doi.org/10.1016/j.jfluidstructs.2003.08.008
  10. Jones, Owen C. Jr., and Zuber, N., 1975, "The Interrelation Between Void Fraction Fluctuations and Flow Patterns in Two-Phase Flow," International Journal of Multiphase Flow, 2, pp. 273-306. https://doi.org/10.1016/0301-9322(75)90015-4
  11. Legius, H.J.W.M., van den Akker, H.E.A. and Narumo, T., 1997, "Measurements on Wave Propagation and Bubble and Slug Velocities in Cocurrent Upward Two-Phase Flow," Experimental Thermal and Fluid Science, 15, pp. 267-278. https://doi.org/10.1016/S0894-1777(97)00012-5
  12. Schrage, D.S., Hsu, J.T. and Jensen, M.K., 1988, "Two-Phase Pressure Drop in Vertical Cross Flow Across a Horizontal Tube Bundle," AIChE J, 34, pp.107-115. https://doi.org/10.1002/aic.690340112
  13. Zuber, N. and Findlay, J., 1965, "Average Volumetric Concentration in Two-Phase Flow System," Trans. ASME Journal of Heat Transfer, 87, pp. 453-468 . https://doi.org/10.1115/1.3689137
  14. Ishii, M., Chawla, T.C. and Zuber, N., 1976, "Constitutive Equation for Vapor Drift Velocity in Two-Phase Annular Flow," AIChE, 22(2), pp.283-289, https://doi.org/10.1002/aic.690220210
  15. Zuber, N., Staub, F.W., Bijwaard, G. and Kroeger, P.G., 1967, "Steady State and Transient Void Fraction in Two-Phase Flow System," GEAP 5471.
  16. Wallis, G.B., 1969, One-Dimensional Two-Phase Flow, McGraw-Hill.
  17. Lockhart, R.W. and Martinelli, R.C., 1949, "Proposed Correlation of Data for Isothermal Two- Phase, Two-Component Flow in Pipes," Chemical Engineering Progress, 45, pp. 39-48.
  18. Baroczy, C.J., 1963, "Correlation of Liquid Fraction in Two-Phase with Application to Liquid Metals," NAA-SR-8171.
  19. Turner, J.R.S. and Wallis, G.B., 1965, The Separated-Cylinders Model of Two-Phase Flow, NYO- 3114-6, Thayer's School Eng., Dartmouth College.
  20. Butterworth, D., 1975, "A Comparison of Some Void-Fraction Relationships for Co-Current Gas- Liquid Flow," International Journal of Multiphase Flow, 1, pp. 845-850. https://doi.org/10.1016/0301-9322(75)90038-5
  21. Pettigrew, M. J., and Taylor, C.E., 1994, "Two-Phase Flow-Induced Vibration: an Review," ASME Journal of Pressure Vessel Technology, 116(3), pp. 233-253. https://doi.org/10.1115/1.2929583
  22. Cheng, H., Hills, J.H. and Azzorpardi, B.J., 2002, "Effects of Initial Bubble Size on Flow Pattern Transition in a 28.9 mm Diameter Column," International Journal of Multiphase Flow, 28, pp. 1047-1062. https://doi.org/10.1016/S0301-9322(02)00013-7
  23. Fenstra, P.A., Weaver, D.S. and Judd, R.L., 2000, "An Improved Void Fraction Model for Two-Phase Cross- Flow in Horizontal Tube Bundles," International Journal of Multiphase Flow, 26, pp. 1851-1873. https://doi.org/10.1016/S0301-9322(99)00118-4
  24. Sim, W.G., 2007, "An Approximate Damping Model for Two-Phase Cross-Flow in Horizontal Tube Bundles," 2007 ASME Pressure Vessel and Piping Division Conference, San Antonio, USA, PVP2007- 26176.
  25. Sim, W. G. and Mureithi, Njuki, W., 2010, "Drag Coefficient and Two-Phase Friction Multiplier On Tube Bundles Subjected to Two-Phase Cross-Flow," ASME 2010 Pressure Vessels & Piping Division / KPVP Conference, Bellevue, Washington, USA, PVP2010-25073.
  26. Martinelli, R. C. and Nelson, D. B., 1948, "Prediction of Pressure Drop During Forced Circulation Boiling of Water," Transactions of ASME, 70, pp. 695-702.
  27. Levy, S., 1960, "Steam Slip-Theoretical Prediction from Momentum Model," Trans. ASME, series C, J. Heat Transfer, 82, pp. 113-124. https://doi.org/10.1115/1.3679890