Analysis of non-laminar flows in coarse alluvial beds has a wide range of applications in various civil engineering, oil and gas, and geology problems. Darcy equation is not valid to analyze transient and turbulent flows, so non-linear equations should be applied. Non-linear equations are classified into power and binomial equations. Binomial equation is more accurate in a wide range of velocit...

Transition of additive and non-additive pulsatile flows through a simple 3D model of arterial stenosis is investigated by using a large eddy simulation (LES) technique. We find in both the pulsatile cases that the interaction of the two shear layers, one of which separates from the nose of the stenosis and the another one from its opposite wall, causes recirculation in the flow downstream of th...

BACKGROUND Decellularized animal organs have been used as scaffolds for tissue engineering. To make a properly functioning scaffolds, the extracellular matrix (ECM) components must be preserved after decellularization. Because pulsatile flow is known to be beneficial for tissue perfusion, pulsatile perfusion of a detergent might decrease the exposure time of the tissues to the detergent used fo...

Natural convection in a square enclosure having two wavy vertical walls is studied. An enclosure is filled with fluid-saturated porous media. A cavity is heated spatially on bottom wall while remaining walls are maintained at lower temperature. The objective of this study is to examine the flow field, temperature distribution and heat transfer inside the cavity when values of Darcy number, Rayl...

background: numerical study of angulation effects of renal arteries on blood flow has been of great interest for many researchers. objective: this paper aims at numerically determining the angulation effects of stenosed renal arteries on blood flow velocity and renal mass flow. method: an anatomically realistic model of abdominal aorta and renal arteries is reconstructed from ct-scan images and...

We present an analysis of the accuracy of the lattice Boltzmann BGK (LBGK) method in simulating pulsatile blood flow in a model of the Human Abdominal Aorta. The flow is driven by a systolic pressure cycle. As a benchmark, we consider fully developed pulsatile flow in a straight tube. We compare velocity profiles and shear stress to the analytical Womersley solutions. The accuracy of the bounce...

In this article we investigate the numerical approximation of the Darcy equations in an axisymmetric domain, subject to axisymmetric data. Rewriting the problem in cylindrical coordinates reduces the 3-D problem to a problem in 2-D. This reduction to 2-D requires the numerical analysis to be studied in suitably weighted Hilbert spaces. In this setting the Raviart-Thomas (RT) and Brezzi-Douglas-...

In this report, a partitioned time stepping algorithm for transient flow in a porous medium coupled to a free flow in embedded conduits is analyzed. The coupled flow is modeled by the fully evolutionary Stokes-Darcy problem. This method requires only solve one, uncoupled Stokes and Darcy sub-physics and subdomain per time step. On the interface between the matrix and conduit, Beavers-Joseph int...

The pumping mechanism of the heart is pulsatile, so the heart generates pulsatile flow that enters into the compliant aorta in the form of pressure and flow waves. We hypothesized that there exists a specific heart rate at which the external left ventricular (LV) power is minimized. To test this hypothesis, we used a computational model to explore the effects of heart rate (HR) and aortic rigid...