We next discuss annular flow solutions As noted earlier in this book annular flow solutions that are useful in petroleum engineering are lacking The only known exact closed-form analytical solution is a classic one describing Newtonian flow in a concentric annulus Let R be the outer radius and κ r be the inner radius so that 0...

Jun 04 2015 0183 32 The laminar flow equations for annular flow are approximate for Newtonian and power-law flow in annuli with low-clearance but reasonably accurate and much simpler than the exact solutions Note that for low clearance annuli the slit flow model provides almost as accurate a result as the concentric annular model but can also be modified to...

fluid through pipe and annulus Results showed that Herschel-Bulkley model gave the best fit for concentric annulus in laminar flow regime For turbulent flow polymer drilling fluid acted as drag reducing fluid and thus the term of pipe roughness in friction pressure loss prediction caused larger results than experiments...

Fully developed laminar transitional and turbulent flow of a Newtonian fluid in an annulus of diameter ratio 00415 was investigated Measurements were made of the axial pressure gradient turbulence intensity velocities location of the point of maximum velocity A range of Reynolds numbers based on the diameter difference and mass flow rate from 750 to 130 000 was covered...

The laminar fluid flow of water through the annulus duct was investigated numerically by ANSYS fluent version 150 with height 25 5 75 cm and constant length L=60cm With constant heat flux applied to...

The laminar flow in annulus was analyzed by different researchers to predict the flow properties such as the pressure drop velocity profiles etc These analyses were used...

Axial Laminar Flow in an Eccentric Annulus an Approximate Solution ISMAIL TOSUN Department of Chemical Engineering Middle East Technical University Ankara Turkey INTRODUCTION 4 = cothvr - cothq While the problem of fluid flow in a concentric annulus has received much attention in the past only in the last two decades an interest has started to develop for the same problem in an ec...

An analysis has been performed to determine the heat transfer charac-teristics for laminar forced-convection flow in a concentric annulus with prescribed surface temperatur The temperatures of the inside and outside walls of the annulus are considered to be different The temperature distri-butions were determined by utilizing the method of superposition...

Keywords laminar ﬂow noncircular ducts hydrodynamic entrance length developing ﬂow modeling pressure drop 1 Introduction Laminar ﬂow ﬂuid friction and heat transfer in noncircular ducts occur quite frequently in low Reynolds number ﬂow heat exchangers such as automotive coolers cold plates and micro-channel heat sinks...

The Annular Orifice block annular leakage in a fully-developed laminar flow created by a circular tube and a round insert in an isothermal liquid network The insert can be located off-center from the tube by an eccentricity value...

Laminar fluid flow and heat transfer A K Agrawal and S Sengupta r r2=l- h u t - B C - Z Figure 1 Geometric representation of an annulus with externally enhanced inner tube Vorticity transport equation...

Feb 25 2020 0183 32 Equations to determine drill string or annulus pressure loss vary according to the flow regimes such as laminar and turbulentIn addition Bingham Plastic and Power Law models differ in form Since these models are frequently used in drilling applications they will be presented in the following sections...

An analytical solution and a numerical analysis are presented to study the flow behavior in concentric annulus with moving core in pipe for laminar flow condition The analytical analysis is presented as exact solution for steady fully developed and one dimensional flow The numerical model is presented to study two-dimensional steady developing and fully developed flows...

The analysis of laminar flow of power-law non- Newtonian fluids in narrow eccentric annuli is employed in this paper to discuss the problems of lubricant flow in journal bearings and of errors introduced by eccentricity in experimental studies with concentric annuli on extruders and wellbore annuli...

Sep 16 2005 0183 32 Flow through an annulus is more complicated than flow through an orifice so empiraical data seems to be needed This is discussed in Lenkei A 1965 Close Clearance Orifices Product Engineering 4/26/65 pp 57-61...

Flow chart for the computer code ANNULUS 96 Fig 41 Pressure defect in laminar flow through an annulus r = 025 98 Fig 42 Variation of friction factor parameter fpRe in the entrance region of an annulus r = 025 99 Fig 43 Variation of Nusselt number for hydrodynamically developing flow through an annulus r = 025 100...

Herein secondary flow effects were introduced into the model but simplification was achieved by using laminar flow The governing equations describing steady laminar flow in an annulus with one or two rotating screens were solved by the finite difference method The resulting algorithm was checked against published results...

Sep 29 2010 0183 32 RE laminar flow in an annulus zdas04 Mechanical 29 Sep 10 15 23 I ve used the Petroleum technique on 15 inch OD coiled tubing in 2-3/8 tubing ID 1996 which works out to 108 inch equivilant diameter and it represented measured data very well...

An analysis is presented of fully developed laminar flow in an eccentric annulus An exact solution for the velocity distribution is presented From this solution may be obtained expressions for local shear stress on the inner and outer surfaces of the annulus friction factors based on the inner and outer surfaces and the overall friction factor...

Discussion The problem of laminar flow in an annulus is similar in nature to that of the laminar flow between parallel plates with the main variance being that the flow is wrapped around the inner cylinder and best solved with cylindrical coordinat This problem has many real world applications such as the flow in an oil well inside a Liebig condenser or coaxial Heat Exchangers...

Apr 01 2019 0183 32 The experimental studies on laminar flow of YPL and PL fluids in the eccentric annulus circular wellbore were conducted by Ahmed 2005 at the University of Tulsa Ahmed 2005 The aqueous of the Xanthan Gum XCD and Polyanionic Cellulose PAC with the different weight concentration was used as the test flu...

Feb 07 2019 0183 32 Made by faculty at the University of Colorado Boulder Department of Chemical Biological Engineering...

incompressible laminar flow of fluid in a straight circular pipe Other examples include flow between two wide parallel plates or flow of a liquid film down an inclined plane In the above situations fluid velocity varies across the cross-section only in one coordinate direction and is uniform in the other direction normal to the flow direction...

Jan 06 2021 0183 32 The most common annular flow regime is laminar It exists from very low pump rates to the rate at which turbulence begins Characteristics of laminar flow useful to the drilling engineer are low friction pressures and minimum hole erosion Laminar flow can be described as individual layers or laminae moving through the pipe or annulus Fig...

Forced flow through the annulus between concentric round tubes of different diameters 4 Gravitational flow of a liquid film down an inclined or vertical plane 5 Gravitational flow of a liquid film down the inner or outer surface of a round Poiseuille Flow Poiseuille law describes laminar flow of a Newtonian fluid in a round tube case 1...

Axial laminar flow in an eccentric annulus An approximate solution...

Thus the recommended steps of calculation to determine the head loss for a laminar annular flow of a pseudoplastic fluid are the following 1 Determination of the radial position R 0 of the maximum velocity by iteration from Eq 1448 2 Knowing R 0 the constant A and the annulus form parameter ϕ can be calculated from Eqs 1450 and...

The laminar eccentric annular flow of non-Newtonian fluids is analyzed with a new method where an eccentric ammulus is represented by an infinite number of concentric annuli with variable outer radii The analytical solutions for the shear stress shear rate velocity and volumetric flow rate/pressure gradient are obtained for both power-law...

The problem of laminar flow in an annulus is similar in nature to that of the laminar flow between parallel plates with the main variance being that the flow is wrapped around the inner cylinder and best solved with cylindrical coordinat This problem has many real world applications such as the flow in an oil well inside a Liebig condenser...

The results of a finite difference analysis are presented for the problem of incompressible laminar flow heat transfer in concentric annuli with simultaneously developing hydrodynamic and thermal boundary layers the boundary conditions of one wall being isothermal and the other wall adiabatic...

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