Velocity measurements of wind blowing near the North Sea border of Northern Germany and velocity measurements under local isotropic conditions of a turbulent wake behind a cylinder are compared. It is shown that wind gusts – measured by means of velocity increments – do show similar statistics to the laboratory data, if they are conditioned on an averaged wind speed value. Clear differences bet...

Three-dimensional three-component (3D3C) velocity measurements were made in the flows surrounding a mechanical valve and a silicone polymer valve. Primary three-dimensional flow features were identified in the instantaneous and ensemble-averaged flows surrounding both valves.

In this paper a new macroscopic k-ε model is developed and validated for turbulent flow through porous media for a wide range of porosities. The morphology of porous media is simulated by a periodic array of square cylinders. In the first step, calculations based on microscopic v2 − f model are conducted using a Galerkin/Least-Squares finite element formulation, employing equalorder bilinear ve...

We study sign changes and scaling laws in the Cartesian components of the velocity and vorticity of rotating turbulence, in the helicity, and in the components of vertically averaged fields. Data for the analysis are provided by high-resolution direct numerical simulations of rotating turbulence with different forcing functions, with up to 1536(3) grid points, with Reynolds numbers between ≈110...

In the present study, a compact analytical model is developed to determine the pressure drop of fully-developed, incompressible, and constant properties slip-flow through arbitrary cross-section microchannels. An averaged firstorder Maxwell slip boundary condition is considered. Introducing a relative velocity, the difference between the bulk flow and the boundary velocities, the axial momentum...

OBJECTIVE To compare uterine artery Doppler velocity and impedance indices in the presence and absence of uterine artery waveform notches, in the prediction of adverse pregnancy outcome in high-risk women. METHODS One hundred and fifty-seven women identified at Doppler screening as being at 'high risk' underwent a further uterine artery Doppler assessment at 24 weeks' gestation. Pulsatility a...

This work examines the azimuthally averaged boundary layer structure of a numerically simulated hurricane. We nominally define the hurricane boundary layer as the layer in which the effects of surface friction are associated with significant departures from gradient wind balance. The boundary layer in the intensifying primary and forming secondary eyewalls is found to be nonlinear. At large rad...

The hydrodynamics, viz. the solids circulation patterns and bubble behavior, of a freely bubbling gas-solid fluidized bed has been investigated experimentally using Particle Image Velocimetry (PIV) combined with Digital Image Analysis (DIA). Coupling of these non-invasive measuring techniques allows us to obtain information on both the bubble behavior and emulsion phase circulation patterns sim...

In the present investigation the distribution of mean velocity, static pressure and total pressure are experimentally studied on an annular curved diffuser of 37.5° angle of turn with an area ratio of 1.284 and centerline length was chosen as three times of inlet diameter. The experimental results then were numerically validated with the help of Fluent and then a series of parametric investigat...

In the present investigation the distribution of mean velocity, static pressure and total pressure are experimentally studied on a C-shape diffuser of 40° angle of turn with an area ratio of 1.278 and centerline length was chosen as three times of inlet diameter. The experimental results then were numerically validated with the help of Fluent and then a series of parametric investigations are c...