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...

This work considers the instability of the jet plume from an overexpanded, shockcontaining convergent-divergent nozzle and attempts to correlate this instability to internal shock-induced separation phenomena. Time resolved wall pressure measurements and Pitot measurements are used as primary diagnostics. For the conditions of this study flow separation is asymmetric resulting in a large separa...

The use of a chevron nozzle/orifice is one the methods heat transfer enhancement and noise reduction. In case synthetic jets, number papers on this topic small. Therefore, jet actuator with three different orifices circular orifice investigated. aim study to find impact shape centerline velocity (measured hot-wire anemometer) determine if reduces generated noise. sound pressure level was strong...

Abstract This historical moment is characterized by a great awareness regarding the need to reduce Greenhouse Gas emissions (GHG), which are responsible for climate change and its detrimental consequences. Green hydrogen produced means of Power-to-Gas technologies from renewables gaining momentum as possible clean fuel future mobility. In such context, traditional injectors hydrocarbon fuels cu...

Vortex rings were generated by driving pistons within circular cylinders of inner diameter D = 72.8 mm at a constant velocity U0 over a distance L = D. The Reynolds number, U0L/(2m), was 2500. The flow downstream of circular and inclined exits was examined using volumetric 3-component velocimetry (V3V). The circular exit yields a standard primary vortex ring that propagates downstream at a cons...

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...