This paper reports on the simulation of the near-nozzle region of a moderate Reynolds number cold jet flow exhausting from a chevron nozzle. The chevron nozzle considered in this study is the SMC001 nozzle experimentally studied by the researchers at the NASA Glenn Research Center. This nozzle design contains six symmetric chevrons that have a five-degree penetration angle. The flow inside the ...

The nozzle shape was investigated in order to develop a high performance nozzle for pulsed Nd:YAG laser cutting, and its effect on fine cutting of thin metal plate was also discussed. In the case of 0.5mm throat diameter Laval throat nozzle with an initial expansion zone, the pressure on workpiece increased, and the straightness of gas flow was improved compared to a traditional straight throat...

\nG ABSTRACT An abrasive waterjet nozzle wear monitoring and compensating mechanism using the frequency domain.acoustic signals geneiated by the jet exiting the nozzle, as input, is prbposed. An artificial neural network which forms the critical iart of this system is developed using the _back-propagatlon algorithm. The trained network is capable of determining the nozzle diameter corresponding...

In this paper, the interaction of a transonic, turbulent axisymmetric jet with the workpiece is studied. Numerical simulations are carried out using an explicit, coupled solution algorithm with solution-based mesh adaptation. Effect of gas pressure and nozzle standoff distance on structure of the supersonic shock pattern is studied. Experiments are carried out to study the effect of processing ...

An experimental and computational study showed that a passive boundary layer control device in the form of a step incorporated just downstream of a nozzle throat can be used to provide good thrust recovery. The nozzle without the step produced an overexpansion of the supersonic °ow. The computational study was performed for a full-scale nozzle under actual engine exhaust and ambient atmospheric...

In this paper, we present our efforts to test experimentally and numerically the concept of bubble augmented jet propulsion. The numerical model is based on a two-way coupling between an Eulerian description of the flow field and a Lagrangian tracking of bubbles using the Surface Averaged Pressure (SAP) model. The numerical results compares favorably with nozzle experiments. A half 3-D nozzle f...

Design Andrew Gelsey and Don Smith ([email protected], [email protected]) Computer Science Department Rutgers University New Brunswick, NJ 08903 Computing in Aerospace 10, San Antonio, TX, March 1995 AIAA-95-1016-CP Copyright c 1995 by Andrew Gelsey and Don Smith. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission. Abstract The Nozzle Design Associ...

BACKGROUND AND OBJECTIVE Cryogen sprays are used for cooling human skin during various laser treatments. Since characteristics of such sprays have not been completely understood, the optimal atomizing nozzle design and operating conditions for cooling human skin remain to be determined. MATERIALS AND METHODS Two commercial cryogenic spray nozzles are characterized by imaging the sprays and th...

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...

In an attempt to ensure good-quality printouts of our technical reports, from the supplied PDF files, we process to PDF using Acrobat Distiller. We encourage our authors to use outline fonts coupled with embedding of the used subset of all fonts (in either Truetype or Type 1 formats) except for the standard Acrobat typeface families of Times, Helvetica (Arial), Courier and Symbol. In the case o...