Numerical solutions based on standard finite volume method are presented for the study of heat transfer and fluid dynamic characteristics in turbulent flows behind a single sided backward-facing step. The calculation of the differential equations is performed using SIMPLE algorithm. For the turbulent quantities standard K-model is used. Predicted mean velocity profiles and reattachment lengths ...

Two-dimensional calculations are performed for a Reynolds number of 1000 and an effective Prandtl number of unity to study the dynamics of large scale spanwise vortices with a passive scalar field in a separation and reattaching flow over a blunt plate. A triple decomposition technique is used to isolate the quasi-periodic fluctuations related to the large scale vortices shed from the separated...

The present research investigates second law analysis of laminar flow over a backward facing step (BFS). Entropy generation due to separation, reattachment, recirculation and heat transfer is studied numerically. Local entropy generation distributions were obtained by solving momentum, energy, and entropy generation equations. The effect of dimensionless temperature difference number (τ) and Br...

Crown reattachment is the most conservative treatment which can be used to restore fractured tooth, presumably with sufficient strength, while maintaining original contour, incisal translucency, and reducing chair time and cost.However, in case of crown fracture with pin-point pulp exposure, we should cautiously minimize the irritation to the pulp and consider pre-treatment pulpal status, choic...

We used a sudden-expansion flow chamber to examine U-937 cell adhesion to unactivated and tumor necrosis factor (TNF)-α-activated human umbilical vein endothelial cells (HUVEC) in recirculating flow. For both unactivated and TNF-α-activated HUVEC, U-937 cells exhibited transient arrests within ∼150 μm of flow reattachment. Few arrests occurred directly at the reattachment site. U-937 cell rolli...

We examined the hypothesis that disturbance of laminar flow promotes the attachment of leukocytes to the vessel wall in regions where the wall shear stress is otherwise too high. Isolated neutrophils, lymphocytes, or monocytes were perfused through chambers with backward-facing steps so that vortices occurred with well-defined reattachment of flow. Wall shear stresses downstream in reestablishe...

Predication of reattachment length of separated shear layers in low Reynolds number turbulent flow is a challenging task to evaluate the capabilities of different turbulence models, especially for MEMS applications. Physical significances of backward facing step and its industrial applications were discussed. Flow analysis of backward facing step in 2D as well as in 3D were carried out by using...

We consider slip with friction and penetration with resistance boundary conditions in the steady state Navier– Stokes equations. This paper describes some aspects of the implementation of these boundary conditions for /nite element discretizations. Numerical tests on twoand three-dimensional channel 2ows across a step using the slip with friction boundary condition study the in2uence of the fri...