화학공학소재연구정보센터
Korea-Australia Rheology Journal, Vol.16, No.1, 47-54, March, 2004
Rheological behavior of dilute bubble suspensions in polyol
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Low Reynolds number, dilute, and surfactant-free bubble suspensions are prepared by mechanical mixing after introducing carbon dioxide bubbles into a Newtonian liquid, polyol. The apparent shear viscosity is measured with a wide-gap parallel plate rheometer by imposing a simple shear flow of capillary numbers (Ca) of the order of 10-2 ~ 10-1 and for various gas volume fractions (φ). Effects of capillary numbers and gas volume fractions on the viscosity of polyol foam are investigated. At high capillary number, viscosity of the suspension increases as the gas volume fraction increases, while at low capillary number, the viscosity decreases as the gas volume fraction increases. An empirical constitutive equation that is similar to the Frankel and Acrivos equation is proposed by fitting experimental data. A numerical simulation for deformation of a single bubble suspended in a Newtonian fluid is conducted by using a newly developed two-dimensional numerical code using a finite volume method (FVM). Although the bubble is treated by a circular cylinder in the two dimensional analysis, numerical results are in good agreement with experimental results.
  1. Brackbill JU, Kothe DB, Zemach C, J. Comput. Phys., 100, 335 (1992) 
  2. Cho WJ, Park H, Youn JR, Proc. Inst. Mech. Eng. Part B, 208, 121 (1994)
  3. Cristini V, Blawzdziewicz J, Loewenberg M, Phys. Fluids, 10(8), 1781 (1998) 
  4. Frankel NA, Acrivos A, J. Fluid Mech., 44, 65 (1970) 
  5. Kim C, Youn JR, Polym. Plast. Technol. Eng., 39(1), 163 (2000) 
  6. Koo MS, Chung K, Youn JR, Polym. Eng. Sci., 41(7), 1177 (2001) 
  7. Lee WH, Lee SW, Kang TJ, Chung K, Youn JR, Fibers Polym., 3(4), 159 (2002)
  8. Leonard BP, Comput. Methods Appl. Mech. Eng., 88, 17 (1991) 
  9. Llewellin EW, Mader HM, Wilson SDR, Proceed. Royal Soc. London Ser. A, 458, 987 (2002)
  10. Loewenberg M, Hinch EJ, J. Fluid Mech., 321, 395 (1996) 
  11. Mackenzie JK, Proceed. Royal Soc. London Ser. B, 63, 2 (1950)
  12. Macosko CV, Rheology: Principles, Measurements, and Applications, Wiley, New York, 425 (1994)
  13. Park H, Youn JR, J. Eng. Ind. ASME Trans., 114(3), 323 (1992)
  14. Park H, Youn JR, Polym. Eng. Sci., 35(23), 1899 (1995) 
  15. Patankar SV, Numerical Heat Transfer and Fluid Flow, McGraw-Hill, New York (1980)
  16. Renardy YY, Cristini V, Phys. Fluids, 13(1), 7 (2001) 
  17. Renardy YY, Renardy M, Cristini V, Eur. J. Mech. B/Fluids, 21, 49 (2002) 
  18. Rust AC, Manga M, J. Non-Newton. Fluid Mech., 104(1), 53 (2002) 
  19. Seo D, Youn JR, Tucker CL, Int. J. Numer. Methods Fluids, 42, 1105 (2003) 
  20. Taylor GI, Proceed. Royal Soc. London Ser. A, 138, 41 (1932)
  21. Tucker CL, Moldenaers P, Annu. Rev. Fluid Mech., 34, 177 (2002) 
  22. Ubbink O, Issa RI, J. Comput. Phys., 153, 26 (1999) 
  23. Yan J, Thiele F, Numer. Heat Transf. B-Fundam., 34, 323 (1998)
  24. Youn JR, Park H, Polym. Eng. Sci., 39(3), 457 (1999)