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为了分析计算粘弹性流体驱替残余油的微尺度力,从水动力学角度探索非牛顿流体的流变特性,选取Oldroyd-B本构方程来模拟粘弹性流体,并结合连续性方程和运动方程得到了粘弹性流体在微孔道中的流动方程,利用边界条件计算得到流动的流场,结合应力张量理论,计算出粘弹性流体作用在残余油上的法向偏应力和水平应力差,计算结果表明:沿流动方向,粘弹性流体的弹性越大,法向偏应力越大;垂直于流动方向,法向偏应力近似对称分布;随着粘弹性流体的弹性变化,水平应力差的变化趋势发生了变化,威森伯格数We越大,残余油所受的水平应力差先逐渐增加,达到峰值后降低,这种趋势更有利于残余油的变形,为下一步分析残余油的变形,并从主体上分离奠定了基础.
In order to analyze and calculate the micro-scale force of visco-elastic fluid displacing residual oil, the rheological properties of non-Newtonian fluids are explored from the hydrodynamic point of view. The Oldroyd-B constitutive equation is chosen to simulate the viscoelastic fluid. Combining the continuity equation and motion equation The flow equation of the viscoelastic fluid in the microchannel was obtained. The flow field was calculated by using the boundary conditions. The normal stress and the horizontal stress difference of the viscoelastic fluid acting on the residual oil were calculated by combining the stress tensor theory. The results show that the larger the elasticity of viscoelastic fluid is, the larger the normal deviatoric stress is along the flow direction. The normal deviatoric stress is approximately symmetrical with respect to the flow direction. With the elastic change of viscoelastic fluid, the variation of horizontal stress difference The larger the Weissenberg number We, the more the horizontal stress difference of the residual oil first increases and reaches the peak value and then decreases. This tendency is more conducive to the deformation of the residual oil. In order to analyze the residual oil deformation, And separated from the main body laid the foundation.