C. Q. Fu et al. / Natural Science 2 (2010) 780-785

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785

785

In Figure 5, at the downstream of the contraction, the

pressures change gently. In the convex area of contrac-

tion, pressures vary intensely and the difference grows

larger with the increase of We. That is to say, the pres-

sure loss mainly happens at corner. The the pressure

drop is larger with a bigger We. The high pressure drop

and high velocity of viscoelastic polymer solution at

corner strengthen the displacement and wash action, and

it will increase the microscopic sweep efficiency.

5. CONCLUSIONS

In this paper, the flow of a UCM model fluid through a

4:1 sudden contraction channel has been studied using a

stable finite volume scheme. The solution method suc-

ceeds in obtaining accurate values for all variables at

elasticity levels up to We = 3.0.

The present simulations reinforce the point that the

FVM can be used as a viable alternative for the solution

of viscoelastic problems. The results are accurate and

offer an improvement over previous numerical solutions.

Although the present study has been applied to a UCM

fluid in a relatively simple geometry, it can be further

extended to other more realistic constitutive equations,

such as the Phan-Thien-Tanner or Giesekus-Leonov mo-

dels, etc. and to other geometries encountered in poly-

mer processing.

Numerical results show that the viscoelasticity of poly-

mer solutions is the main factor influencing sweep effi-

ciency. With increasing elasticity, the flowing area in the

corner is enlarged significantly, thus the area with immo-

bile zones becomes smaller. Flow velocity is larger than

that for a Newtonian fluid, the sweep area and displace-

ment efficiency increase as the elasticity increases. The

pressure drop in the convex area is larger with a bigger

elasticity, and it will strengthen the displacement and wash

action at the corner. The viscoelastic behavior of the dis-

placing polymer fluids can in general improve the dis-

placement efficiency in pores compared to using Newto-

nian fluids. This conclusion should be useful in selecting

polymer fluids and designing polymer flooding operations.

REFERENCES

[1] Zhang, L.J. and Yue, X.A. (2007) Mechanism for visco-

elastic polymer solution percolating through porous

media. Journal of Hydrodynamics Series B, 19(2), 241-

248.

[2] Wang, D.M. and Lin, J.Z. (2008) Influence of the

microforce produced by viscoelastic displacement of

liquid on displacement efficiency. Journal of Xi’an

Shiyou University (Natural Science Edition), 23(1), 43-

55.

[3] Yin, H.J., Wang, D.M. and Zhong, H.Y. (2006) Study on

flow behaviors of viscoelastic. polymer solution in

micropore with dead end. SPE 101950, San Antonio,

Texas, 786-795.

[4] Yin, H.J. and Zhong, H.Y. (2007) Numerical simulations

of viscoelastic flows through one slot Channel. Jour- nal

of Hydrodynamics, Series B, 19(2), 210-216.

[5] Wang, D.M., Cheng, J.C. and Yang, Q.Y. (2000) Vis-

couselastic polymer can increase in cores. SPE 63227,

Dallas, Texas, 719-728.

[6] Huang, Y.Z., Yu, D.S. and Zhang, G.F. (1990) The study

on micro polymer flooding mechanism. Oilfield Che-

mistry, 3, 57-60.

[7] Yin, H.J. and Jiang, H.M. (2008) Bhavior of SPTT

viscoelastic fluid in contraction channel. Petroleum

Geology & Oilfield Development in Daqing, 27(2), 56-

59.

[8] Zhang, L.J. (2001) Flow of voscoelastic fluid throught

complex pores and its effect on microscopic displace-

ment efficiency. Daqing Peturelum Institute, 37-37.

[9] Aboubacar, M., Matallah, H. and Webster, M.F. (2002)

Highly elastic solutions for Oldroyd-B and Phan-Thien/

Tanner fluids with a finite volume/element method:

Planar contraction flows. Non-Newtonian Fluid Mech,

103(1), 65-103.

[10] Jiang, H.M. (2009) The study on microscopic porous

flow behavior of polymer solutions. Daqing Peturelum

Institute, 10-26.

[11] Patankar, S.V. (1980) Numerical heat transfer and fluid

flow [M]. New York, Hemisphere.

[12] Deng, J., Ren, A.L. and Zou, J.F. (2006) Three-

dimensional flow around two tandem circular cylinders

with various spacing at Re = 200. Journal of Hydro-

dynamics, Series B, 18(1), 48-54.

[13] Bao, F.B., Lin, J.Z. and Liu, Y.H. (2006) Research on the

flow property in three dimensional cavity of micro-

channel. Journal of Hydrodynamics, Series B, 18(1),

20-25.

[14] Qu, J.P. and Xia, G.F. (1998) Reaserch on elastic

behaviors of LDPE melt during capillary dynamic

extrusion. Journal of South China University of Tech-

nology (Natural Science), 11, 76-80.

[15] Fortin, A. and Zine, A. (1992) An improved GARES

method for solving viscoelastic fluid flow problems.

Non-Newtonian Fluid Mechanics, 42(1-2), 1-18.