The purpose of this study is to analyse the transport and stirring of fluid that occurs owing to the formation and growth of a laminar vortex ring. Experimental data was collected upstream and downstream of the exit plane of a piston–cylinder apparatus by particle-image velocimetry. This data was used to compute Lagrangian coherent structures to demonstrate how fluid is advected during the tran...

The mixing efficiency of a flow advecting a passive scalar sustained by steady sources and sinks is naturally defined in terms of the suppression of bulk scalar variance in the presence of stirring, relative to the variance in the absence of stirring. These variances can be weighted at various spatial scales, leading to a family of multi-scale mixing measures and efficiencies. We derive a prior...

Traditionally, the Reverberation Chamber (RC) has been used for EMC testing, but recently it has been developed for measuring antennas and mobile terminals designed for wireless applications. It is a metal cavity, large in terms of wavelength which supports several cavity modes at the operation frequency. The modes are stirred by appropriate stirring methods producing a rich scattering environm...

Over fifty years ago, Carl Eckart described the sequence of processes as a passive scalar is stirred and mixed in a turbulent flow (Eckart, 1948). At first, during the stirring phase, the variance of the scalar gradient is greatly increased, but later, during the mixing phase, the gradients become sufficiently sharp that molecular diffusion becomes important and the gradient variance rapidly de...

Hydroxyapatite (HA) whiskers have been synthesized using a number of chemical solution methods, including the chelate decomposition method. Numerous previous studies have investigated the effects of the reagents, reagent concentrations, solution pH, and reaction temperature on HA whisker morphology and composition. However, purely kinetic effects, such as the reaction heating and stirring rates...

125301-7474 IJET-IJENS @ February 2012 IJENS I J E N S Abstract—To better understand the vacuum arc remelting (VAR) process, a 3D finite element model is established to analyzing the electromagnetic, temperature and flow fields of titanium alloy ingot during steady state melting process using ANSYS software. The research results show that the current flows from the crucible to consumable electr...

Investigations for the melt growth gallium-antimonide (GaSb) semiconductor crystals are underway at the US Air Force Research Laboratory at Hanscom Air Force Base by the vertical gradient freeze (VGF) method utilizing a submerged heater. Electromagnetic stirring can be induced in the gallium-antimonide melt just above the crystal growth interface by applying a weak radial electric current in th...