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

The Korean Society of Mechanical Engineers (대한기계학회)
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Numerical Study of Wavy Film Flow on Vertical Plate Using Different Turbulent Models

난류 모형에 따른 수직 평판 위 파동 액막류의 수치해석 연구

  • Min, June Kee (Rolls-Royce University Technology Center, Pusan Nat'l Univ.) ;
  • Park, Il Seouk (School of Mechanical Engineering, Kyungpook Nat'l Univ.)
  • 민준기 (부산대학교 롤스로이스 대학기술센터) ;
  • 박일석 (경북대학교 기계공학부)
  • Received : 2012.10.10
  • Accepted : 2013.11.18
  • Published : 2014.05.01
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Abstract

Film flows applied to shell-and-tube heat exchangers in various industrial fields have been studied for a long time. One boundary of the film flow interfaces with a fixed wall, and the other boundary interfaces with a gaseous region. Thus, the flows become so unstable that wavy behaviors are generated on free surfaces as the film Reynolds number increases. First, high-amplitude solitary waves are detected in a low Reynolds number laminar region; then, the waves transit to a low-amplitude, high frequency ripple in a turbulent region. Film thickness is the most significant factor governing heat transfer. Since the wave accompanied in the film flow results in temporal and spatial variations in film thickness, it can be of importance for numerically predicting the film's wavy behavior. In this study, various turbulent models are applied for predicting low-amplitude ripple flows in turbulent regions. The results are compared with existing experimental results, and finally, the applied turbulent models are appraised in from the viewpoint of wavy behaviors.

액막류는 다양한 산업분야에 적용되는 쉘-튜브 열교환기의 주요 열교환기구로 오랫동안 연구되어왔다. 액막류의 한쪽 경계는 고정벽에 접하고 있지만 반대편에서는 기체 영역과 경계를 형성하므로 액막 레이놀즈 수가 증가함에 따라 쉽게 불안정해지는 특징을 가지고 있다. 따라서 레이놀즈 수가 증가함에 따라 자유표면 파동 현상이 나타나는데, 층류 영역에서는 큰 진폭의 고립파가, 난류 천이 이후에는 낮은 진폭의 물결파가 나타난다. 액막류의 열전달 성능은 액막의 두께에 의해 크게 지배받는데 액막류에 동반된 파동은 액막 두께의 시공간적 변화를 의미하는 것이므로 이에 대한 정보를 해석적으로 수집하는 것은 액막류 열전달 성능을 예측하는데 필수적이다. 본 연구에서는 낮은 진폭의 물결파를 동반한 난류 액막류에 대하여 여러 가지 난류 모형을 적용한 해석결과들을 실험결과와 비교함으로써 난류 모형들에 대한 평가를 실시하였다.

Keywords

References

  1. Nusselt, W., 1916, "Die Oberflachen Kondensation des Wasserdampes, Zeitsehrit des Vereines Deutscher Ingenieure," Vol. 60, pp. 541-575.
  2. Faghri, A. and Seban, R. A., 1988, "Heat and Mass Transfer to a Turbulent Liquid Film," Int. J. Heat Mass Transfer, Vol. 31, No. 4, pp. 891-894. https://doi.org/10.1016/0017-9310(88)90145-7
  3. Chun, M.-H. and Kim, K.-T., 1990, "Assessment of the New and Existing Correlations for Laminar and Turbulent Film Condensations on a Vertical Surface," Int. Commun. Heat Mass Transfer, Vol. 17, pp. 431-441. https://doi.org/10.1016/0735-1933(90)90062-O
  4. Park, I. S. and Choi, D. H., 1996, "Analysis of LiBr-H2O Film Absorption on a Horizontal Tube," Trans. Korean Soc. Mech. Eng. B, Vol. 20, No. 2, pp. 670-679.
  5. Grigoreva, N. I. and Nakoryakov, V. E., 1977, "Exact Solution Combined Heat and Mass Transfer Problem During Film Absorption," J. Eng. Phys., Vol. 33, No. 5, pp. 1349-1353. https://doi.org/10.1007/BF00860913
  6. Grossman, G., 1982, "Simultaneous Heat and Mass Transfer in Film Absorption under Laminar Flow," Int. J. Heat Mass Transfer, Vol.25, No.3, pp.357-371.
  7. Min, J. K. and Park, I. S., 2011, "Numerical Study for Laminar Wavy Motions of Liquid Film Flow on Vertical Wall," Int. J. Heat Mass Transfer, Vol. 54, pp. 3256-3266. https://doi.org/10.1016/j.ijheatmasstransfer.2011.04.005
  8. Takamasa, T. and Hazuku, T., 2000, "Measuring Interfacial Waves on Film Flowing Down a Vertical Plate Wall in the Entry Region Using Laser Focus Displacement Meters," International Journal of Heat and Mass Transfer, Vol. 43, pp. 2807-2919. https://doi.org/10.1016/S0017-9310(99)00335-X
  9. Hirshburg, R. and Florschuetz, L., 1982, "Laminar Wavy-film Flow: Part I, Hydrodynamic Analysis," Journal of Heat Transfer, Transaction of the ASME, Vol. 104, pp. 452-458. https://doi.org/10.1115/1.3245114
  10. Jayanti, S. and Hewitt, G., 1997, "Hydro dynamics and Heat Transfer in Wavy Annular Gas-liquid Flow : a Computational Fluid Dynamics Study," Int. Journal of Heat and Mass Transfer, Vol. 40, pp. 2445-2460. https://doi.org/10.1016/S0017-9310(96)00288-8
  11. Fluent 6.3 Users Guide, Fluent Inc., 2006.
  12. Abid, R., 1993, "Evaluation of Two-Equation Turbulence Models for Predicting Transitional Flows," International Journal of Engineering Science, Vol. 31, pp. 831-840. https://doi.org/10.1016/0020-7225(93)90096-D
  13. Gibson, M. M. and Launder, B. E., 1978, "Ground Effects on Pressure Fluctuations in the Atmospheric Boundary Layer," J. Fluid Mech., Vol. 86, pp. 491-511. https://doi.org/10.1017/S0022112078001251
  14. Park, I. S., Kim, Y. J. and Min, J. K., 2011, "Comparison of Numerical Results for Laminar Wavy Liquid Film Flows Down a Vertical Plate for Various Time-differencing Schemes for the Volume Fraction Equation," Trans. Korean Soc. Mech. Eng. B, Vol. 35, No. 11, pp. 1169-1176. https://doi.org/10.3795/KSME-B.2011.35.11.1169
  15. Ito, A. and Sasaki, M., 1986, "Breakdowon and Formulation of a Liquid Film Flowing Down an Inclined Plane," Transaction of the Japan Society of Mechanical Engineers, Vol. 52, pp. 1261-1265. https://doi.org/10.1299/kikaib.52.1261
  16. Wilcox, D. C., 1993, Turbulence Modeling for CFD, DCW Industries.
  17. White, F. M., 2006, Viscous Fluid Flow, McGraw Hill.
  18. Liu, J., Schneider, J. B. and Gollub, J. P., 1995, "Three-dimensional Instabilities of Film Flows," Physics of Fluids, Vol. 7, pp. 55-67. https://doi.org/10.1063/1.868782