Nozzle

About: Nozzle is a research topic. Over the lifetime, 158675 publications have been published within this topic receiving 893026 citations. The topic is also known as: spout.

Ballistic imaging of the near field in a diesel spray

Abstract: We have developed an optical technique called ballistic imaging to view breakup of the near-field of an atomizing spray. In this paper, we describe the successful use of a time-gated ballistic imaging instrument to obtain single-shot images of core region breakup in a transient, single hole atomizing diesel fuel spray issuing into one atmosphere. We present a sequence of images taken at the nozzle for various times after start of injection, and a sequence taken at various positions downstream of the nozzle exit at a fixed time. These images contain signatures of periodic behavior, voids, and entrainment processes.

The effects of nozzle diameter on impinging jet heat transfer and fluid flow

Abstract: The effects of nozzle diameter on heat transfer and fluid flow are investigated for a round turbulent jet impinging on a flat plate surface. The flow at the nozzle exit has a fully developed velocity profile. A uniform heat flux boundary is created at the plate surface by using gold film Intrex, and liquid crystals are used to measure the plate surface temperature. The experiments are performed for the jet Reynolds number (Re) of 23,000, with a dimensionless distance between the nozzle and plate surface (L/d) ranging from 2 to 14 and a nozzle diameter (d) ranging from 1.36 to 3.40 cm

A novel nozzle for more efficient sperm orientation to improve sorting efficiency of x and y chromosome-bearing sperm

Abstract: Efficient high-resolution detection of DNA for flow cytometric sorting of X and Y chromosome-bearing sperm is dependent on effectively orientating the sperm head to the laser beam in orthogonally configured flow systems. Normally, a beveled needle is required to enlarge the fraction of properly orientated sperm (flat side facing the laser beam). In this report, a modification to a standard jet-in-air nozzle for improved sperm orientation is presented. Inside the modified nozzle (novel nozzle), orientation forces are applied lower in the nozzle than in the current beveled injection needle system. The nozzle was tested with sperm heads from several species. This study shows that use of the nozzle to orientate cattle, swine, rabbit, mouse, and human sperm effectively improves the percentage of sperm that are properly oriented. The percentage of sperm heads oriented by use of the former system (beveled needle) ranges around 30% for most species. With the newly designed nozzle, that percentage ranges around 60%. At least a twofold increase in analysis is achieved. It was found that, unlike results with the beveled needle, the percentage of properly oriented sperm was independent of the sample rate. The introduced nozzle is a significant improvement over the beveled needle system for the analysis and sorting of sperm on the basis of DNA content. In addition to the improvement in sorted sperm production brought about by the novel nozzle when fitted to standard-speed cell sorters, it clearly also has significant potential for improving the efficiency of the Beltsville Sperm Sexing Technology for separating X and Y chromosome-bearing sperm when adapted to high-speed cell-sorting systems. Cytometry 33: 476–481, 1998. Published 1998 Wiley-Liss, Inc.

Generating complicated surface with electrolyte jet machining

Abstract: In the electrolyte jet machining (EJM), the electrolytic current is supplied between the anodic workpiece and the cathodic nozzle via the electrolyte which is ejected from the minute nozzle. Only the workpiece material exposed to the jet is removed due to the anodic dissolution, because the electrolytic current is restricted to the limited area by the jet. In this study, an electrolyte jet machining system which can be used to process the complicated three-dimensional surface was constructed. This system is composed of an XY stage, a rotating axis and a high-speed bipolar power supply, all of which are cooperatively controlled by a personal computer. An algorithm was developed to obtain the scanning path and speed of the nozzle to process complicated shape by superimposing simple patterns. The optimized path and speed were thus obtained so that the summation of the squared difference between the superimposed and the required patterns at every checking point becomes minimal. In order to verify the effectiveness of the developed algorithm, simulation and experiment were carried out and the machining accuracy was analyzed. The good agreement between the simulated and produced shapes with the required one proves that the algorithm meets the purpose properly. Besides, the effect of machining conditions, especially the current density on surface roughness of produced patterns was examined. It was clarified that a high current density is not only necessary to reduce machining time but also to improve the surface roughness.