The study of flow and heat transfer over rotating circular disks is of great practical importance in understanding the cooling of rotatory machinery such as turbines, electric motors and design and manufacturing of computer disk drives. This paper presents an analysis of the flow and heat transfer over a heated infinite permeable rough disk. Boundary-layer approximation reduces the elliptic Nav...

      Water flux in a young, 4-year old, cashew (Anacardium occidentale L.) plantation was studied over a dry season, from November 2001 to March 2002, in the forest-savannah transition zone of Ghana, West Africa. The temperature-difference method was used over this five-month period to quantify the diurnal and day-to-day whole-tree sap flow (Qt) and hence the canopy scale transpiration (Ec). M...

Transition from laminar flow to turbulent flow occurs very often and plays a crucial role in many practical engineering flows. There are many different kinds of transition and broadly speaking they can be classified into three categories: classical transition in attached boundary; bypass transition in attached boundary layer and separated boundary layer transition. This paper presents a compara...

in this research, shock wave motion, shock/boundary layer interaction, and flow separation in a transonic flow over a naca0012 airfoil were investigated experimentally. thirteen kulite sensors were utilized for measurement of pressure fluctuations over the airfoil. experiments were performed for angles of attack between -4 to 4 degrees and flow mach numbers of m= 0.39 to 0.82. the kulite sensor...

This paper investigates the characteristics of wall pressure fluctuations in naturally developing boundary layer flows on axisymmetric bodies experimentally. The axisymmetric body has a modified ellipsoidal blunt nose. Flush-mounted microphones are used to measure the wall pressure fluctuations in the boundary layer flow over the body. The measurements are performed in a low noise wind tunnel. ...

– We study theoretically the effects of confinement on active polar gels such as the actin network of eukaryotic cells. Using generalized hydrodynamics equations derived for active gels, we predict, in the case of quasi one-dimensional geometry, a spontaneous flow transition from a homogeneously polarized immobile state for small thicknesses, to a perturbed flowing state for larger thicknesses....

Pipe flow is perhaps the classic problem of fluid dynamics. Its simplicity of form lends itself admirably to experimenters but conceals a wealth of unanswered questions. Despite Reynolds’ conducting his seminal experiments over a century ago, few formal results are known for this flow. Over the years many simplifications have been considered, including linearisation, azimuthal invariance and st...

We consider the inverse mean curvature flow in RobertsonWalker spacetimes that satisfy the Einstein equations and have a big crunch singularity and prove that under natural conditions the rescaled inverse mean curvature flow provides a smooth transition from big crunch to big bang. We also construct an example showing that in general the transition flow is only of class C.

Direct numerical simulation of transitional pipe flow is carried out in a long computational domain in order to characterize the dynamics within the saddle region of phase space that separates laminar flow from turbulent intermittency. For Reynolds numbers ranging from Re=1800 to 2800, a shoot and bisection method is used to compute critical trajectories. The chaotic saddle or edge state approa...

The details of the start-up transient vortex structure that forms near the junction of an impulsively started plate and a stationary plate where a step jump in velocity occurs at the plate surfaces are investigated. Numerical simulations have been conducted in a geometry representative of recent experiments of this flow. The experiments did not have access to data at very early times following ...