An Experimental Study of the Fluid Dynamics of Multiple Noncritical Stenoses

Talukder, N.; Karayannacos, Panayotis E.; Nerem, Robert M.; Vasko, John S.

doi:10.1115/1.3426276

Cited by 32 publications

(26 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Again the features similar to those observed at Re = 1200 are clearly noticed at Re = 800 and mildly at Re = 200. At Re = 100 no ow separation is noticed on the diverging walls of both the constrictions and is exactly in agreement with the experimental observations of Talukder et al [13].…”

Section: Resultssupporting

confidence: 91%

“…When these constrictions are positioned close to one another, they would be expected to interact with each other and their combined e ect could be di erent from the non-interacting case. Talukder et al [13] and Van Dreumel and Kuiken [14] have carried out experimental studies related to ow dynamics in doubly contricted vessels. Recently, Lee [15] and Damodaran et al [16] have made 2D steady ow computational analysis of ow in multiply constricted vessels.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A numerical study of an unsteady laminar flow in a doubly constricted 3D vessel

Kumar

Yamaguchi²,

Liu³

et al. 2002

Numerical Methods in Fluids

View full text Add to dashboard Cite

SUMMARYUnsteady ow dynamics in doubly constricted 3D vessels have been investigated under pulsatile ow conditions for a full cycle of period T . The coupled non-linear partial di erential equations governing the mass and momentum of a viscous incompressible uid has been numerically analyzed by a time accurate Finite Volume Scheme in an implicit Euler time marching setting. Roe's ux di erence splitting of non-linear terms and the pseudo-compressibility technique employed in the current numerical scheme makes it robust both in space and time. Computational experiments are carried out to assess the in uence of Reynolds' number and the spacing between two mild constrictions on the pressure drop across the constrictions. The study reveals that the pressure drop across a series of mild constrictions can get physiologically critical and is also found to be sensitive both to the spacing between the constrictions and the oscillatory nature of the in ow proÿle. The ow separation zone on the downstream constriction is seen to detach from the diverging wall of the constriction leading to vortex shedding with 3D features earlier than that on the wall in the spacing between the two constrictions.

show abstract

Section: Resultssupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

A numerical study of an unsteady laminar flow in a doubly constricted 3D vessel

Kumar

Yamaguchi²,

Liu³

et al. 2002

Numerical Methods in Fluids

View full text Add to dashboard Cite

show abstract

“…The maximum contribution of the SGS model also increases at the region of the second stenosis. The upper wall pressure drops and wall shear stress increase rapidly in the region of stenoses for increasing the Reynolds numbers, which are consistent with the results of Talukder et al [15] and Damodaran et al [9]. It is clearly seen that the maximum pressure drops and wall shear stress occur due to the effects of the second stenosis.…”

Section: Discussionsupporting

confidence: 90%

“…One experimental investigation was done by Talukder et al [15] to study the effects of multiple stenoses on the pressure drop for various Reynolds numbers ranging from 30 to 280. They reported that the intensity of pressure drop increases owing to the presence of multiple stenoses.…”

Section: Introductionmentioning

confidence: 99%

Large Eddy Simulation of Pulsatile Flow through a Channel with Double Constriction

Molla

Paul

2016

Fluids

View full text Add to dashboard Cite

Pulsatile flow in a 3D model of arterial double stenoses is investigated using a large eddy simulation (LES) technique. The computational domain that has been chosen is a simple channel with a biological-type stenosis formed eccentrically on the top wall. The pulsation was generated at the inlet using the first four harmonics of the Fourier series of the pressure pulse. The flow Reynolds numbers, which are typically suitable for a large human artery, are chosen in the present work. In LES, a top-hat spatial grid-filter is applied to the Navier-Stokes equations of motion to separate the large-scale flows from the sub-grid scale (SGS). The large-scale flows are then resolved fully while the unresolved SGS motions are modelled using a localized dynamic model. It is found that the narrowing of the channel causes the pulsatile flow to undergo a transition to a turbulent condition in the downstream region; as a consequence, a severe level of turbulent fluctuations is achieved in these zones. Transitions to turbulent of the pulsatile flow in the post stenosis are examined through the various numerical results, such as velocity, streamlines, wall pressure, shear stresses and root mean square turbulent fluctuations.

show abstract

“…In that case, viscous friction, as accounted for in the first term of these equations, would cause the major pressure loss, since length would be large, and the second term, reflecting exit pressure loss, would be fairly small in the absence of a discrete lesion. As a variation of this same question, the combined effects of multiple stenoses in series can be accounted for by appropriate fluid dynamic analysis Talukder et al, 1977).…”

Section: Relation Between Anatomic and Functional Characteristics Of mentioning

confidence: 99%