The present work analyzes the effects of a solid boundary and the inertial forces on flow and heat transfer in porous media. Specific attention is given to flow through a porous medium in the vicinity of an impermeable boundary. The local volume-averaging technique has been utilized to establish the governing equations, along with an indication of physical limitations and assumptions made in th...

A boundary layer wind tunnel facility has been adopted in order to conduct experimental measurements of the flow field around a model of the Panorama Giustinelli Building, Trieste (Italy). Information on the main flow structures has been obtained by means of flow visualization techniques and has been compared to the numerical predictions of the vortical structures spread on top of the roof, in ...

The application of a novel technique for 3-D visualization of a zero-pressure gradient turbulent boundary layer is discussed. Measurements of a 1.65δ x 1.65δ x 1.65δ volume were taken at a flow speed of 96 ft/s, Reθ ~ 5900, and δ = 1.21 inches in a 2 ft x 2 ft open circuit wind tunnel. Many different mechanisms for flow seeding were explored in order to find the most suitable technique. Experim...

A new two-layer model has been proposed to study microscale heat transfer associated with a developing flow boundary layer. As an example, a cold, microscale film of liquid impinging on an isothermal hot, horizontal surface has been investigated. The boundary layer is divided into two regions: a micro layer at microscale away from the surface and a macro layer at macroscale away from the surfac...

Zooplankton swimming near the substratum experience boundary layer flow that is characterized by steep velocity gradients and turbulence. How do small swimming organisms navigate flows at this interface to forage and interact with mates? To address this question, we collected field measurements of the swimming behavior of the marine ostracod Paravargula trifax near complex living substrata, whi...

Stents are medical devices designed to modify blood flow in aneurysm sacs, in order to prevent their rupture. Some of them can be considered as a locally periodic rough boundary. In order to approximate blood flow in arteries and vessels of the cardio-vascular system containing stents, we use multi-scale techniques to construct boundary layers and wall laws. Simplifying the flow we turn to cons...

The objective has been to study turbulent boundary layers under adverse pressure gradients (APG) through direct numerical simulation (DNS). The numerical code is based on a pseudo-spectral technique which is suitable for the simple geometry (flat plate) considered here. A large effort has been put into the optimization of the numerical code on various super computers. Five large simulations hav...

Stents are medical devices designed to modify blood flow in aneurysm sacs, in order to prevent their rupture. They can be considered as a locally periodic rough boundary. In order to approximate blood flow in arteries and vessels of the cardio-vascular system containing stents, we use multi-scale techniques to construct boundary layers and wall laws. Simplifying the flow we turn to consider a 2...

The optimal shape of a two dimensional turbulator above an isothermal flat plate is found by using numerical simulation. The turbulent boundary layer over the flat plate was disrupted at various situations by inserting a quadrilateral bar where the boundary layer thickness kept more than three times greater than the insert\'s height. As a result, the overall heat transfer coefficient of the wal...

A wind-tunnel model was developed to study the two-dimensional turbulent boundary layer in adverse and favourable pressure gradients with out the effects of streamwise surface curvature. Experiments were performed at Mach 4 with an adiabatic wall, and mean flow measurements within the boundary layer were obtained. The data, when viewed in the velocity transformation suggested by Van Driest, sho...