To compensate for the insufficiency and instability of solder paste dispensing and printing that are used in the SMT (Surface Mount Technology) production process, a noncontact solder paste jetting system driven by a piezoelectric stack based on the principle of the nozzle-needle-system is introduced in this paper, in which a miniscule gap exists between the nozzle and needle during the jetting...

The discharge of grains from a hopper or silo has received considerable attention, both because it is relevant to numerous industries, and a model system for examining general features of granular flow [1, 2]. These studies have generally focused on the motion of grains inside the hopper and the flow rate of material out of the nozzle. It is known that these systems can exhibit intermittent jam...

Starting flow through a nozzle or orifice typically results in the transient formation of a leading vortex ring and trailing jet. Experiments are conducted to investigate the dynamics of this process in the case of a temporally variable nozzle exit diameter, with the aim of understanding these flows as they occur in Nature and emerging technologies. By kinematically decoupling the source flow f...

\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 research mass transfer coefficient under jetting regime in different directions (from dispersed to continuous and continuous to dispersed phase) has been studied using an experimental setup. n-Butanol-succinic acid-water with low interfacial tension has been selected as experimental chemical system. The effects of various parameters such as jet velocity, nozzle diameter and the heig...

Abstract: In this study, the effect of fuel injection discharge curve and injection pressure simultaneously for upgrading power of heavy duty diesel engine by simulation of combustion process in AVL-Fire software are discussed. Hence, the fuel injection discharge curve was changed from semi-triangular to rectangular which is usual in common rail fuel injection system. Injection pressure with r...

in this research mass transfer coefficient under jetting regime in different directions (from dispersed to continuous and continuous to dispersed phase) has been studied using an experimental setup. n-butanol-succinic acid-water with low interfacial tension has been selected as experimental chemical system. the effects of various parameters such as jet velocity, nozzle diameter and the height o...

Cryogen spray cooling is used to prevent epidermal thermal damage during port-wine stain laser therapy, despite the limited understanding of the fluid dynamics, thermodynamics, and heat transfer characteristics of cryogen sprays. In recent studies, it has been suggested that the heat flux through human skin could be increased by changing physical parameters such as nozzle-to-skin distance, nozz...

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 paper describes results of a factorial experiment on coal cutting at a traverse speed of 5 meters/min, with water jets at pressures between 500 and 2,000 atmospheres and nozzle diameters in the range from 0.5 to 1 mm. These results fill a gap in the existing results on coal cutting with water jets and form the basis for the design of a coal cutting machine. The interrelationship between pr...