Prediction of mass transfer from spheres and cylinders in forced convection

Grafton, R. W.

doi:10.1016/0009-2509(63)80034-2

Cited by 25 publications

(5 citation statements)

References 14 publications

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“…At large length and velocity scales, mass transfer can be influenced heavily by background flows in dissolution [53][54][55][56] and melting [57,58]. At smaller length scales there are important applications in chemical and industrial engineering, and geophysics, from mass transfer from one or two spheres, cylinders, or bodies of revolution [59][60][61][62][63][64], to more general shapes and finer-scale details [65][66][67]. Among other pharmaceutical applications are hydrodynamic manipulation of dissolution for drug-delivery purposes [68][69][70][71][72][73][74].…”

Section: Introductionmentioning

confidence: 99%

A generalized traction integral equation for Stokes flow, with applications to near-wall particle mobility and viscous erosion

Mitchell

Spagnolie

2017

Journal of Computational Physics

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A double-layer integral equation for the surface tractions on a body moving in a viscous fluid is derived which allows for the incorporation of a background flow and/or the presence of a plane wall. The Lorentz reciprocal theorem is used to link the surface tractions on the body to integrals involving the background velocity and stress fields on an imaginary bounding sphere (or hemisphere for wallbounded flows). The derivation requires the velocity and stress fields associated with numerous fundamental singularity solutions which we provide for free-space and wall-bounded domains. Two sample applications of the method are discussed: we study the tractions on an ellipsoid moving near a plane wall, which provides a more detailed understanding of the well-studied glancing and reversing trajectories in the context of particle sedimentation, and the erosion of bodies by a viscous flow, in which the surface is ablated at a rate proportional to the local viscous shear stress. Simulations and analytical estimates suggest that a spherical body in a uniform flow first reduces nearly but not exactly to the drag minimizing profile and then vanishes in finite time. The shape dynamics of an eroding body in a shear flow and near a wall are also investigated. Stagnation points on the body surface lead generically to the formation of cusps, whose number depends on the flow configuration and/or the presence of nearby boundaries.

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Section: Introductionmentioning

confidence: 99%

A generalized traction integral equation for Stokes flow, with applications to near-wall particle mobility and viscous erosion

Mitchell

Spagnolie

2017

Journal of Computational Physics

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“…Colburn (3) proposed that /VSh«<3 (4) and this has been accepted and verified by many subsequent workers (6-8, [12][13][14]29). Ruckenstein (32) pointed out that the Schmidt group exponent is a function of the magnitude of the Schmidt group of the system and recent work by many workers (16,18,20,21) has shown that it may vary from 0.15 to 0.33. However, Equation 4 is still the most favored form of relation between the Sherwood and Schmidt numbers and has been assumed to be true for the present case also.…”

Section: Resultsmentioning

confidence: 99%

“…Using Prandtl's boundary layer theory and neglecting the compressibility of the surrounding fluid and gravitational effects, Froessling (6)(7)(8) showed that for nonangular bodies of revolution, the forward part Sherwood number is directly proportional to the square root of the Reynolds number. Most subsequent workers have used this approach in correlating their results and have used a relation of the form Nsh -A + BNngN$c (5) Many workers (6-8, 14,17,19,25,29,31) have assigned a value of 2 to A, assuming it to be purely a contribution from the molecular diffusion (16,23,29). Effect of particle size on kc Figure 3.…”

Section: Resultsmentioning

confidence: 99%

Material transport from nonspherical particles

Upadhyay¹,

Singh²,

Dwivedi³

et al. 1976

J. Chem. Eng. Data

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Forced convective mass transfer between a solid nonspherical particle and water was studied for 0.1993 < (Dp/Dc) < 0.477 and 50 < WRec < 25000. No effect of (Dp/Dc) was observed in the range studied. The experimental results were correlated by NShNs¿/3 = 0.5844 <,c + 0.006012 /VRec. Mass (or heat) transfer between particles surrounded by a continuous fluid phase is of importance in many engineering operations. Typical examples include absorption, adsorption, aerodynamics, bubble plate distillation column, calcining, catalytic beds, desorption, drying, liquid-liquid and solid-liquid extraction, leaching, nuclear reactors, and spray drying. Although most of these operations involve multiparticle systems, due to simplicity, transfer from single spheres, droplets, etc., has received much attention.Transfer of mass (or heat) between a particle and a surrounding fluid phase can occur by three mechanisms: diffusion (or conduction), natural convection, and forced convection. These mechanisms may act individually or collectively. The actual nature of the combination and interaction of individual mechanisms is still largely unresolved; however, their role may be described by the conventional dimensionless groups used to correlate the overall mass (or heat) transfer rates, i.e., by A/Sh (or NNu) = f[NPe, /sc (or NPr), /VGr]

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“…(9) and (10) are virtually identical. The value of the coefficient B 2 is found to be between 0.55 and 0.95 [25][26][27][28][29][30][31]. Mass transfer between fluidized solid particles and liquid has been studied extensively over a wide range of Reynolds numbers.…”

Section: Discussionmentioning

confidence: 99%

Intensification of mass transfer in liquid fluidized beds with inert particles

Yang¹,

Renken²

1998

Chemical Engineering and Processing: Process Intensification

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The influence of inert particles on liquid/solid mass transfer is studied in fluidized beds by using a binary-mixture of solids of differing size and density. The addition of inert particles of higher density and smaller diameter, e.g. glass beads, exerts remarkable effects on mass transfer coefficients in comparison to that of mono-component active particles at the same liquid velocity. The extent of the effect on liquid-solid mass transfer coefficients increases with an increasing fraction of the small inert particles in the mixture. The liquid-solid mass transfer coefficients for binary-mixtures are well correlated in terms of dimensionless groups and the voidage parameter.

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Prediction of mass transfer from spheres and cylinders in forced convection

Cited by 25 publications

References 14 publications

A generalized traction integral equation for Stokes flow, with applications to near-wall particle mobility and viscous erosion

A generalized traction integral equation for Stokes flow, with applications to near-wall particle mobility and viscous erosion

Material transport from nonspherical particles

Intensification of mass transfer in liquid fluidized beds with inert particles

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