Results are presented for physical experiments that illustrate the possibilities and efficiency of visualization for studying the effect of operating conditions (backward-facing stepped forming nozzle, exit diameter of anode, mass flow, and composition of working gas) on plasma flows at low Reynolds numbers for advanced coating and powder processing. In particular, the shadow method, based on a...

This report describes an experimental and numerical study of impinging, incompressible, axisymmetric, laminar jets, where the jet axis of symmetry is aligned normal to the wall. Particle Streak Velocimetry (PSV) is used to measure axial velocities along the centerline of the flow field. The jet-nozzle pressure drop is measured simultaneously and determines the Bernoulli velocity. The flowfield ...

in high-pressure axial turbines, when the fluid mass flow is low, the supersonic blades are being used to obtain a high specific work output. to prevent losses due to low blade aspect ratio, the turbine is used in partial admission conditions. the turbine stator is a group of convergence-divergence nozzles that provides the supersonic flow. the design of these nozzles is important, because ther...

Premixed methane-air mixture is introduced at the center of two parallel circular quartz plates separated by a millimeter scale distance (<or= 5mm). Two plates are heated with an external heater to create a positive temperature gradient condition along the flow direction. The combustion characteristics of lean methane-air mixtures are investigated at phi=0.67 and phi=0.85 in the laminar flow re...

In this report, the radiation of sound from an annular duct exit with buried inner nozzle system, with jet and bypass flow, is studied. This problem represents a simplified model of the radiation of fan and turbine noise from engine exhausts. The model consist of two semi-infinite ducts. The smaller duct (inner nozzle), whose exit plane coincides with the larger one or extends beyond it, is sit...

Computational modeling is an important tool to understand and stabilize transient turbulent fluid flow in the continuous casting of steel to minimize defects. The current work combines the predictions of two steady Reynolds-averaged Navier–Stokes (RANS) models, a ‘‘filtered’’ unsteady RANS model, and two large eddy simulation (LES) models with ultrasonic Doppler velocimetry (UDV) measurements i...

A stable capillary liquid jet formed by an electric field is an important physical phenomenon for formation of controllable small droplets, power generation and chemical reactions, printing and patterning, and chemical-biological investigations. In electrohydrodynamics, the well-known Taylor cone-jet has a stability margin within a certain range of the liquid flow rate (Q) and the applied volta...

used pet bottles disposal is an unsolved environmental problem, and there are many efforts for finding an applicable solution for it. many researches have showed that the degradation rate of the polymers increase with the smaller size of fibers. this work was carried out to convert used pet bottles into nanofibers by melt-electrospinning method. uncolored, washed and chipped pet bottles and the...

SUMMARY Temperature measurements, using the SLR method, are presented for the expansion of nitrogen in nozzles attached to a shock-tube. The measurements were made at an area ratio of 8.5 in a two-dimensional nozzle and at an area ratio of 152 in a conical nozzle. Initial conditions were such that at the entrance to the nozzles the temperature ranged between about 2500 K and 5300 K and the pres...

An inkjet nozzle with double piezo transducers has been designed, which is different from conventional inkjet nozzles. The body of the nozzle which is fabricated by precision machining techniques is made from transparent acrylic material to visualize the flow inside the nozzle. The piezoelectric actuators are activated by a voltage amplifier which generates high-voltage bipolar waveforms. The k...