The expected flow asymmetry behind a three-dimensional notchback Ahmed body is numerically investigated using large-eddy simulations with different blockage ratios of 0%, 5%, 10%, and 20%. focus the study on natural bi-stable influenced by ratio. Although wake can be observed under ratio within 0%−10%, significant influence sensitive bi-stability indicated structures, pressure gradients, dynami...

The unsteady flow features of a series of two-dimensional, planar base flows are examined, within a range of low-supersonic Mach numbers in order to gain a better understanding of the effects of compressibility on the organized global dynamics. Particle image velocimetry is used as the primary diagnostic tool in order to characterize the instantaneous near wake behavior, in combination with dat...

Nomenclature The overall properties of turbulence c, = generated by uniform fluxes of monodisperse D = spherical particles moving through a uniform = flowing gas were studied both theoretically and t(k) = experimentally. Mean and fluctuating values, f = probability density functions and energy spectra of fr = streamwise and cross-stream velocities were measured within a counter-flowing particle...

Plunging airfoils are investigated for applications such as Micro-Air Vehicles (MAVs) and bird and fish like propulsion. Plunging or flapping wings can provide more propulsive efficiency than that of fixed wings, especially at small to moderate Reynolds numbers, where the MAVs (due to their small size) operate. Furthermore, it has been observed that birds and insects rely on detaching and separ...

Abstract The entrainment model applied firstly by P. Luzzatto-Fegiz can predict the streamwise velocity of far-wake more accurately than traditional models (e.g., Jensen model, Frandsen model). current however, neglects wind speed drop approaching rotor caused blockage effect, phenomenon which cannot be considered in recovery region, further affecting precision wake prediction. Hence, this pape...

An object’s wake in a plasma with small Debye length that drifts across the magnetic field is subject to electrostatic electron instabilities. Such situations include, for example, the moon in the solar wind wake and probes in magnetized laboratory plasmas. The instability drive mechanism can equivalently be considered drift down the potential-energy gradient or drift up the density-gradient. T...

background & aim : mother-infant separation is one of the main causes of sleep-wake states disorders in neonatal intensive care unit (nicu). the current study was conducted to investigate the effect of in-arms-holding by mothers on sleep-wake states disorders of preterm neonates. methods & materials : in a pilot study, through a semi-experimental pretest-posttest method, 35 preterm neonates wit...

Marine current energy converters or tidal turbines represent an emerging renewable energy technology that can provide a predictable supply of electricity. Single devices are in operation around the world with aspirations to deploy farms or arrays of multiple devices. We present an experimental study that has characterised the downstream wake flow around a 1/15thscale turbine in a large circulat...

This experimental works summarize the (1), aeroacoustic results of airfoil self-noise generated at Reynolds numbers between 1.0 x 10 and 6.0 x 10. The test facility is a newly built low noise and low flow turbulence open jet wind tunnel, where a NACA0012 airfoil was mounted to the exit nozzle horizontally. The noise measurements were performed at three effective angles of attack at 0.0, 1.4 and...