We observe that decreasing the inner nozzle surface by adding longitudinal ribs increases jet stability in terms of amount turbulent kinetic energy near shear layer. try to explain our observation as a stabilization effect secondary flow vortices emerging corners ribs. These stream-wise damage development larger-scale structures This explanation is supported autocorrelation function velocity co...

Drop-on-demand (DOD) electrohydrodynamic (EHD) jet printing uses a nozzle and pulsated electric fields to eject small ink droplets of functional material to the appointed spot of a substrate at the appointed time, which offers solutions of high resolution patterning for fabrication of printed electronics, bioengineering, and display. Because the EHD jet connects fine drops to yield a fine patte...

A numerical analysis is carried out to determine the flowfield and starting characteristics of a straight cylindrical supersonic exhaust diffuser of a high-altitude simulation of a high expansion ratio rocket nozzle. The flow field inside the high-altitude facility is analyzed for a conical nozzle of expansion ratio of 25, diffuser inlet-to-nozzle throat area ratio of 28.9, and diffuser length-...

This work consists of studying the effect of needle motion of typical single-hole injectors on spray characteristics. Three-dimensional moving mesh simulations have been carried out to calculate the injection process of cylindrical and conical geometries. The CFD analysis includes a numerical model which simulates the effect of cavitation. Results show that the flow within the nozzle and at the...

Although the information set out here focuses (because of their market leading positions) on the Andersen Cascade Impactor (ACI) and Next Generation Impactor (NGI), all multistage cascade impactors operate on the same principle: size fractionation on the basis of inertial impaction. Instruments such as the ACI and NGI consist of a series of stages each made up of a nozzle plate, with a specific...

The efficiency of two G-vacs (Ryobi RSV 3100 and Flymo BVL 320) was tested to examine the effects of increasing the suction nozzle area and the sampling time whilst keeping total sampling area constant (0.49 m). We tested an a priori hypothesis that increasing nozzle area was significant but that reducing sampling time was not, using a planned comparisons approach. We found that when the nozzle...

Solution blow spinning (SBS) is an innovative process for spinning micro/nanofibers. In this paper, polyamic acid (PAA) nanofibers were fabricated via a SBS apparatus and then imidized into polyimide (PI) nanofibers via thermal process. The morphology and diameter distributions of PAA nanofibers were determined by scanning electron microscope (SEM) and Image Tool software, the processing parame...

Bioprinting is an emerging technology in the field of tissue engineering and regenerative medicine. The process consists of simultaneous deposition of cells, biomaterial and/or growth factors under pressure through a micro-scale nozzle. Cell viability can be controlled by varying the parameters like pressure and nozzle diameter. The process itself can be a very useful tool for evaluating an in ...

The hot water sprays are an important part of many industrial processes, where the detailed knowledge of physical phenomena involved in jet transportation, interaction, secondary breakup, evaporation, and coalescence of droplets is important to reach more efficient processes. The objective of the work was to study the water spray jet breakup dynamics, vortex cloud formation, and droplet size di...

This work highlights the possibility of using microstructured fibres with predefined doped regions to produce functional microstructures at a fibre facet with differential chemical etching. A specially designed silica microstructured fibre (MSF) that possesses specific boron-doped silica regions was fabricated for the purpose of generating a radial micronozzle array. The MSF was drawn from a pr...