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...

Background: Oral feeding problems are among the most common issues in preterm infants. Various methods and feeding support tools are used in this regard, such as cup feeding and feeding nozzle. The present study aimed to determine the preferred method between cup feeding and feeding nozzle to support oral feeding in premature neonates. Methods: This clinical trial was conducted on 70 preterm i...

\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 ...

C i c ^ A one-dimensional theory based upon fundamental flow relationships ^ is presented for analyzing the behavior of one or more gas streams flowing MM through a single nozzle. This conpound-coropressible flow theory shows that f^ the behavior of each stream is influenced by the presence of the other ^^ streams. The theory also shows that the behavior of coiTpound--coiTpressible flow is pred...

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...

The comparisons of two typical fluidic thrust vectoring exhaust nozzles including two-dimensional(2-D) nozzle and axisymmetric nozzle on aerodynamic characteristics was presented by numerical simulation. The results show: the thrust vector angles increased with the increasing secondary flow but decreased with the nozzle pressure ratio (NPR) increasing. With the same secondary flow and NPR, the ...

This paper presents the analysis of a two phase flow ejector for the transcritical CO2 cycle. A detailed simulation model of a two phase flow ejector was developed. A controllable ejector expansion device was designed, constructed, and installed in a transcritical CO2 experimental air conditioning system. System-level experimental results were obtained at different operation conditions and vari...

Expansion work recovery by two-phase ejector is known to be beneficial to vapor compression cycle performance. However, one of the biggest challenges with ejector vapor compression cycle is that the ejector cycle performance is sensitive to working condition changes which are common in real world applications. Different working conditions require different ejector geometries to achieve maximum ...

A straightforward procedure has been developed to quickly determine an inviscid design of a hypersonic wind tunnel nozzle when the test gas is both calorically and thermally imperfect. This real gas procedure divides the nozzle into four distinct parts: subsonic, throat to conical, conical, and turning flow regions. The design process is greatly simplified by treating the imperfect gas effects ...