# مقالههای Ahmad Ramazani S.A.

**توجه:**محتویات این صفحه به صورت خودکار پردازش شده و مقالههای نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده میشوند.

##### ۱Simulation of Generalized Newtonian Fluid Flow in Micropore with Dead End

اطلاعات انتشار:
هجدهمین کنفرانس سالانه مهندسی مکانیک،
سال ۱۳۸۹

تعداد صفحات:
۴

The flow characteristics of power–law generalized Newtonian fluid types in porous pores in reservoir with the dead ends are simulated numerically to find effects of fluids and flow character on replacement ability of flooding fluid with trapped oil in the dead ends. The contours of velocity and stream function are drawn and micro–scale sweep efficiency is calculated qualitatively. The power law model has been used to describe the rheological properties of polymer solutions. This model considers viscosity shear dependent behavior of fluids which can dramatically affects flow behavior of polymer solutions in reservoirs. A finite–volume–based numerical approach has been used to solve the equations of motion for the steady, isothermal and incompressible power–law fluid past through a two–dimensional micropore. The streamline plots showing the nature offluid on flow dynamic are presented. The computed result over the range of the power–law index range of 0.1 ≤ n ≤ 2 (covering both shear–thinning and shearthickening behavior) are shown. Numerical results show the power law index of polymer solutions is the main factor influencing sweepefficiency. With increasing power law index, the flowing area in the dead end of pores becomes bigger. The sweep area and displacement efficiency increase as the power law index increases. The shear–thickening nature of the displacing polymer fluids in general can improve the displacement efficiency in pores compared to shear–thinning and Newtonian fluids. This conclusion could be employed in selecting polymer fluids and designing polymer flooding operations.<\div>

##### ۲Simulation of Oldroyd–B Viscoelastic Fluid Flow in Expansion Channels

اطلاعات انتشار:
چهاردهمین کنگره ملی مهندسی شیمی ایران،
سال ۱۳۹۱

تعداد صفحات:
۵

Viscoelastic fluids play significant roles in many industrial sectors, such as in food and synthetic polymers industries. The rheological response of viscoelastic fluids is quite complex, including combination of viscous and elastic effects. In this study, we present simulation results on viscoelastic fluid, i.e. Oldroyd–B, flows in sudden expansion geometry were applied in two–dimensional Cartesian coordinates. The governing equations intransient and fully developed regions were solved using OpenFOAM software. The velocity profiles, shear stresses, and first normal stress differences in some horizontal and vertical sections are illustrated. The simulation results indicated that the maximum of shear stress and first normal stress difference occurred in the inlet of channel and the changes of shear stress and first normal stress difference were linear along the channel length<\div>

##### ۳Effects of viscoelastic polymer solutions on the oil extraction from dead ends

اطلاعات انتشار:
Scientia Iranica،
بيستم،شماره۶، ۲۰۱۳،
سال ۰

تعداد صفحات:
۹

This research deals with the numerical simulation of two viscoelastic fluids flow in an open capillary of a reservoir. The Oldroyd–B and Leonov models have been used to describe the rheological behavior of polymer solutions. The nite volume method on a structured and collocated grid has been used for discretization the governing equations. The discrete elastic viscous stress splitting technique also has been used. The steady state, isothermal and incompressible fluids past through a two dimensional micropore have been considered. The numerical method has been validated through the comparison of numerical results by the analytical solutions of Oldroyd–B fluid flow through a planar channel.The effects of fluid characteristics and operating conditions on the oil sweeping from the dead ends are investigated. The contours of velocity, stream function and pressure are presented, and the swept depth is calculated. The presented results show that with increasing the Weissenberg number the swept depth of ooding fluid in the dead ends increases considerably. However, in the studied range, the Reynolds number does not have any signi cant e ects on the sweep efficiency. The results also show that the swept depth in the case of viscoelastic fluids is more than the Newtonian and generalized Newtonian fluids.

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