... lens, and 500 mm spherical lens to illuminate a vertical plane every 1 mm from ±5 mm from the centerline (0 mm) for region II. Only the 0 mm and ±5 mm planes were captured for regions I and III. To quantify turbulent fluctuations and eddy formation, 1000 image pairs were continuously captured at 55...

...Rayanne Pinto Costa; Blaise Simplice Talla Nwotchouang; Junyao Yao; Dipankar Biswas; David Casey; Ruel McKenzie; Frederick Sebastian; Rouzbeh Amini; David A. Steinman; Francis Loth Previous experimental flow studies have demonstrated a delay (∼20%) in transition to turbulence for whole blood...

...-Newtonian behavior at higher shear rates. However, less is known about the impact of its multiphase nature on the transition to turbulence. In this study, we experimentally determined the critical Reynolds number at which the flow began to transition to turbulence downstream of eccentric stenosis for whole...

... of transitional flow in aneurysms, turbulence has not received much attention. In this article, we investigate turbulence in the context of abdominal aortic aneurysms (AAA). Since the clinical practice is to diagnose an AAA on the basis of its size, hypothetical axisymmetric geometries of various sizes...

....2010.01.025 [17] Defraeye , T. , Blocken , B. , Koninckx , E. , Hespel , P. , and Carmeliet , J. , 2010 , “ Computational Fluid Dynamics Analysis of Cyclist Aerodynamics: Performance of Different Turbulence-Modelling and Boundary-Layer Modelling Approaches ,” J. Biomech. , 43...

... change in cross-sectional area does not usually occur in a normal human aorta; hence, the absence of spatial flow retardation. Thus, using RANS-based CFD [ 17 ], the aim of the present study is to test further Menter's SST transitional turbulence model for flow in a realistic aorta and to compare...

...F. P. P. Tan; N. B. Wood; G. Tabor; X. Y. Xu In this study, two different turbulence methodologies are investigated to predict transitional flow in a 75% stenosed axisymmetric experimental arterial model and in a slightly modified version of the model with an eccentric stenosis. Large eddy...

... mimicked the flow fields in several medical devices, consisted of a gradual flow constriction, a narrow throat region, and a sudden expansion region where a fluid jet exited the center of the nozzle with recirculation zones near the model walls. Measurements of mean velocity and turbulent flow quantities...

... of diagnostic and predictive value. Recirculation zones, vortex shedding, and secondary flows are captured by both laminar and turbulent solutions. The forces on vessel walls are shown to correlate with unstable plaque deposits. Performing before and after studies of vessels in long-term radiology studies may...

...Roland Gårdhagen; Jonas Lantz; Fredrik Carlsson; Matts Karlsson Large eddy simulation was applied for flow of Re = 2000 in a stenosed pipe in order to undertake a thorough investigation of the wall shear stress (WSS) in turbulent flow. A decomposition of the WSS into time averaged and fluctuating...

... patient were analyzed based on computed tomography images acquired from the patient. Computational simulations of blood flow in the patient-specific model were performed by employing a correlation-based transitional version of Menter’s hybrid k - ε / k - ω shear stress transport turbulence model...

... pediatric aorta. The three great vessels originating from the aortic arch— brachiocephalic (innominate), left common carotid, and left subclavian arteries—are included. An implicit large eddy simulation method based on a finite volume approach is used to study the resulting turbulent flow. A resistance...

...Ning Yang; Steven Deutsch; Eric G. Paterson; Keefe B. Manning We use an implicit large eddy simulation (ILES) method based on a finite volume approach to capture the turbulence in the anastomoses of a left ventricular assist device (LVAD) to the aorta. The order-of-accuracy of the numerical schemes...

...%. The present study revealed that turbulent air-particle flow may propagate to G5 for the assumed inhalation flow rate. Geometry and upstream effects are more pronounced for micron particle deposition than for nanoparticle deposition. Kleinstreuer , C. , Zhang , Z. , and Li , Z. , 2008...

...F. P. P. Tan; G. Soloperto; S. Bashford; N. B. Wood; S. Thom; A. Hughes; X. Y. Xu In this study, newly developed two-equation turbulence models and transitional variants are employed for the prediction of blood flow patterns in a diseased carotid artery where the growth, progression, and structure...

...Sonu S. Varghese; Steven H. Frankel; Paul F. Fischer Mean flow predictions obtained from a host of turbulence models were found to be in poor agreement with recent direct numerical simulation results for turbulent flow distal to an idealized eccentric stenosis. Many of the widely used turbulence...

... geometric simplifications of the realistic model. A validated low Reynolds number k - ω turbulence model was employed to simulate laminar, transitional, and fully turbulent flow regimes for the transport of 1–200 nm particles. Results of this study indicate that the geometric simplifications considered did...

...J. Banks; N. W. Bressloff Under normal healthy conditions, blood flow in the carotid artery bifurcation is laminar. However, in the presence of a stenosis, the flow can become turbulent at the higher Reynolds numbers during systole. There is growing consensus that the transitional k − ω model...

... different Reynolds numbers, one in the laminar regime and the other turbulent (near-peak systole flow rate), are investigated. A direct numerical simulation is carried out for the laminar flow case while the turbulent flow is investigated with two different unsteady statistical turbulence modeling...

..., was identified by the location of vortical structures and level of coherence corresponding to a significant variation in the turbulence level distribution inside the LV. The adverse effect of these observations could potentially compromise the efficiency of the LV and result in flow patterns that deviate from...