Previous investigations have shown that the size of a regurgitant jet as assessed by color Doppler flow mapping is independently affected by the flow rate and velocity (or driving pressure) of the jet. Fluid dynamics theory predicts that jet momentum (given by the orifice flow rate multiplied by velocity) should best predict the appearance of the jet in the receiving chamber and also that this ...

Numerical simulation has been performed by solving full Navier–Stokes equations governing the three-dimensional unsteady compressible flows. The main goal of the present work is to investigate the flow characteristics of a square jet issuing transversally into a cross-flow at three injection angles of 90°, 60° and 30°, and thus to provide some deeper insights into the physical flow mechanism go...

The one-phase flow and the two-phase flow in a fluidic element are investigated by measuring Reynolds stress distributions of the main jets using the laser Doppler velocimeter. In the one-phase flow, a water flow jets from a main nozzle into water and in the two-phase flow, a water fiow jets into air. Some results with the one-phase flow are as follows. When either of the two control ports is c...

This research aims to study jet downstream scour model under the influence of changes of water level. It also studies and analyzes different parameters and components of diffusion of submerged jet flow in an acceptor fluid and scour hole dimensions. To achieve the objectives, a physical model was made in proportion to the research title. With the Froude number increasing in a nozzle discharge, ...

Two-phase flow instability in microchannel flow boiling exhibits pressure fluctuations with different frequencies and amplitudes. One possible way to suppress the dynamic instability is to introduce synthetic jet near the inlet of the channel. An important feature of synthetic jet is that it allows momentum transfer into the microchannel flow without net mass injection into it. The strength and...

Direct numerical simulations have been performed to study the behaviour of multiple square jets issuing normally into a cross-flow. The jets are arranged side-by-side in spanwise direction in twin jet configuration and with addition third jet downstream along the centre line in tandem jets configuration. The simulations are carried out for the jet-to-jet adjacent edge distances of 1D and 2D in ...

Abstract. The changes in vortical and turbulent structure in the near field (X/D < 3.0) of jet mixing flow caused by a lobed nozzle were investigated experimentally in the present study. The techniques of planar laser induced fluorescence and particle image velocimetry were used to accomplish flow visualization and velocity field measurements. The experimental results showed that, compared with...

The vortical and turbulent structure changes in the near field (X/D<3.0) of the jet mixing flow caused by a lobed nozzle had been investigated experimentally in the present study. The techniques of planar Laser Induced Fluoresce (LIF) and Particle Image Velocimetry (PIV) were used to accomplish the flow visualization and velocity field measurements. The experimental results showed that, compare...

Direct numerical simulations are performed to predict the three-dimensional unsteady flow interactions in the near-field of a square jet issuing normal to a cross-flow. The simulated flow features reveal the formation of an upstream horseshoe vortex system, which is the result of an interaction between the oncoming channel floor shear layer and the transverse jet; the growth of a sequence of Ke...

An axisymmetric jet issued from a sharp edged circular convergent nozzle has been studied experimentally in the near field at Reynolds number 5.3x104  to search the saddle shape behavior of mean velocity and the role of mean static pressure in the jet flow. Due to the vena contracta effect the centerline mean velocity of the jet increases about 4.2% of its exit value and corresponding decrease ...