Shear-augmented solute dispersion during drug delivery for three-layer flow through microvessel under stress jump and momentum slip-Darcy model

2021 ◽  
Author(s):  
G. Bashaga ◽  
S. Shaw
Keyword(s):  
Drug Delivery ◽  
Stress Jump ◽  
Darcy Model ◽  
Solute Dispersion ◽  
Flow Through ◽  
Layer Flow

scholarly journals Viscous effects in two-layer, unidirectional hydraulic flow

2010 ◽  
Vol 644 ◽  
pp. 371-394
Author(s):  
MARTIN S. SINGH ◽  
ANDREW McC. HOGG
Keyword(s):  
Control Point ◽  
Lower Boundary ◽  
Internal Gravity Waves ◽  
Velocity Shear ◽  
Hydraulic Control ◽  
Viscous Effects ◽  
Unidirectional Flow ◽  
Boundary Case ◽  
Flow Through ◽  
Layer Flow

Hydraulic equations are derived for a stratified (two-layer) flow in which the horizontal velocity varies continuously in the vertical. Viscosity is included in the governing equations, and the effect of friction in hydraulically controlled flows is examined. The analysis yields Froude numbers which depend upon the integrated inverse square of velocity but reduce to the original layered Froude numbers when velocity is constant with depth. The Froude numbers reveal a critical condition for hydraulic control, which equates to the arrest of internal gravity waves.Solutions are presented for the case of unidirectional flow through a lateral constriction, both with and without bottom drag. In the free-slip lower boundary case, viscosity transports momentum from the faster to the slower layer, thereby shifting the control point downstream and reducing the flux through the constriction. However, while the velocity shear at the interface between the two layers is reduced, the top-to-bottom velocity difference of the controlled solution is increased for larger values of viscosity. This counter-intuitive result is due to the restrictions placed on the flow at the hydraulic control point. When bottom drag is included in the model, the total flux may increase, in some cases exceeding that of the inviscid solution.

Maximal two-layer exchange over a sill and through the combination of a sill and contraction with barotropic flow

1986 ◽  
Vol 164 ◽  
pp. 53-76 ◽  
Author(s):  
D. M. Farmer ◽  
L. Armi
Keyword(s):  
Surface Layer ◽  
Reverse Flow ◽  
Single Layer ◽  
The Other ◽  
Exchange Flow ◽  
Strait Of Gibraltar ◽  
Exchange Flows ◽  
Barotropic Flow ◽  
Flow Through ◽  
Layer Flow

The analysis of two-layer exchange flow through contractions with a barotropic component treated by Armi & Farmer (1986) is extended to include exchange flows over sills and through a combination of a sill and contraction. It is shown that exchange over a sill is fundamentally different from exchange through a contraction. Control at the sill crest acts primarily through the deeper layer into which the sill projects and only indirectly controls the surface layer. This asymmetry in the control results in asymmetrical flows. The interface depth above the crest is not one half the total depth, as assumed in other studies by analogy with flow through contractions, but is somewhat deeper; the maximal exchange rate is less than for flow through a contraction of equal depth. When both a sill and a contraction are present, the contraction influences control at the sill crest only if it lies between the sill and the source of denser water. The response to barotropic flow is also asymmetrical: the transition to single-layer flow occurs at much lower speeds for a barotropic component in one direction than the other.Results of the analysis are applied to exchange flow through the Strait of Gibraltar, which includes both a sill and a contraction. It is shown that maximal exchange conditions apply throughout part of the tidal cycle, and observations illustrate several of the analytical predictions for barotropic flows, including the formation of fronts, single-layer flow, submaximal exchange and reverse flow.

A Theoretical Investigation of Transonic Flows in Radial Compressor Diffusers

1983 ◽  
Vol 105 (3) ◽  
pp. 452-456
Author(s):  
H. O. Jeske ◽  
I. Teipel
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Pressure Ratio ◽  
Numerical Procedure ◽  
Vaned Diffuser ◽  
High Pressure Ratio ◽  
Integral Methods ◽  
Boundary Layer Interaction ◽  
Flow Through ◽  
Layer Flow

The transonic flow in a diffuser of a centrifugal compressor with high pressure ratio has been analyzed by a numerical procedure. The method consists of an inviscid calculation of the pressure field in the vaned diffuser and of a determination of the boundary layer flow along the blades. The diffuser has been equipped with curved vanes, and only the flow through one channel is considered. The two-dimensional pressure distribution has been calculated by a time-dependent finite difference scheme. The boundary layer flow has been determined by different integral methods with special attention concerning the shock-boundary-layer interaction. Finally, the numerical results are compared with experiments, and the agreement is satisfactory.

A TWO LAYER FLOW THROUGH A CONTRACTION

1975 ◽  
Vol 13 (1) ◽  
pp. 19-34 ◽  
Author(s):  
K. K. Lai ◽  
I. R. Wood
Keyword(s):  
Flow Through ◽  
Layer Flow

scholarly journals Generation of multilayered structures for biomedical applications using a novel tri-needle coaxial device and electrohydrodynamic flow

2008 ◽  
Vol 5 (27) ◽  
pp. 1255-1261 ◽  
Author(s):  
Z Ahmad ◽  
H.B Zhang ◽  
U Farook ◽  
M Edirisinghe ◽  
E Stride ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Controlled Release ◽  
Biomedical Engineering ◽  
Biomedical Applications ◽  
Short Communication ◽  
Multilayered Structures ◽  
Electrohydrodynamic Flow ◽  
Novel Device ◽  
Flow Through ◽  
Controlled Flow

In this short communication, we describe the scope and flexibility of using a novel device containing three coaxially arranged needles to form a variety of novel morphologies. Different combinations of materials are subjected to controlled flow through the device under the influence of an applied electric field. The resulting electrohydrodynamic flow allows us to prepare double-layered bubbles, porous encapsulated threads and nanocapsules containing three layers. The ability to process such multilayered structures is very significant for biomedical engineering applications, for example, generating capsules for drug delivery, which can provide multistage controlled release.

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