Modeling of gas flow inside and outside the nozzle used in spray deposition

Jeyakumar, M; Gupta, G. S.; Kumar, Shakti

doi:10.1016/j.jmatprotec.2007.10.070

Cited by 14 publications

(6 citation statements)

References 22 publications

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“…The sum of each seven channel sections was equal to the vertical central channel section to maintain the flow rate. 24 This unsteady motion problem was converted to a steady-state problem by imposing a moving frame of reference on a static mesh. A motion reference frame (MRF) was thus considered for all rotating parts in a static outlet condition.…”

Section: Integration Of Milling Tool Rotationmentioning

confidence: 99%

Tool design effect on microlubrication spray efficiency in milling using inner channels

Duchosal

Serra

Leroy³

et al. 2016

Proceedings of the Institution of Mechanical Engineers, Part B:

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This study consisted in investigating parameters that significantly influence the spray efficiency of minimum quantity lubrication in a milling tool with inner channels. An initial experimental approach was used to estimate the oil mist consumption and outlet particle velocities with different inlet pressures, for different shapes of inner channels, without rotation (static part). An experimental versus simulation comparison was undertaken between outlet velocities as a function of inlet pressure. The Reynolds-averaged Navier–Stokes model with the Lagrangian multiphase models was validated by comparing experimental and numerical outlet velocities for different inlet pressures. A numerical rotating tool with inner channels was used with the validated model in the second numerical simulation to analyze the influences of inlet conditions (inlet pressure) based on the tool shape and the rotation velocity, in a dynamic approach. The main objective of the oil mist is to reach the cutting edge (qualifying the minimum quantity lubrication spray efficiency) depending on the inlet conditions (inlet pressures) and the machining configurations (rotation velocities) by analyzing the streamlines of the oil mist particles. The study pointed out the tool design effect combined with its rotation velocity on the oil mist capability to reach the cutting edge. This study offered a trend of parameter sets to provide correct inlet parameters based on machining configurations. At high rotation speed, the inlet pressures needed to be high enough to counter the aerodynamic effects occurred by the tool design.

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Section: Integration Of Milling Tool Rotationmentioning

confidence: 99%

Tool design effect on microlubrication spray efficiency in milling using inner channels

Duchosal

Serra

Leroy³

et al. 2016

Proceedings of the Institution of Mechanical Engineers, Part B:

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“…A similar approach has been implemented to study the spray coating and spray forming processes in Refs. [107,30,32]. However, only the droplet spray characteristics were investigated and the deposition and film formation on the substrate were not considered in their studies.…”

Section: Dielectric Spray Modelmentioning

confidence: 99%

Atomized Dielectric Spray-Based Electric Discharge Machining (Spray-EDM) for Sustainable Manufacturing

Pattabhiraman

Marla

Kapoor

2015

Volume 1: Processing

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Electrical Discharge Machining is a non-traditional machining process that is widely used in the tool and die-making industry, automotive, and aerospace industries due to its ability to produce complex three-dimensional geometries with good accuracy and surface finish. Despite the aforementioned advantages, the consumption of a large quantity of dielectric (especially hydrocarbon oils) poses a significant health and environmental hazard including respiratory and skin irritation issues. Further, the disposal of waste dielectric that contains a significant amount of metal particulates poses safety concerns. In order to comply with environmental safety standards, extensive filtration and treatment systems capable of handling huge amounts of dielectric waste need to be set up for their safe disposal.This leads to an increased energy consumption and hence higher operating cost for the machining process. Thus, there is a need to reduce the consumption of oil-based dielectrics without compromising their superior machining performance.Several techniques including dry and near-dry EDM have been developed to reduce the consumption of dielectrics. However, they have poor debris flushing capability. This research seeks to develop a technique that minimizes the consumption of dielectrics and also improves the flushing of debris from the inter-electrode gap.A novel method of using atomized dielectric spray in EDM (Spray-EDM) to reduce the consumption of dielectric is developed in this study. The atomized dielectric droplets form a moving dielectric film up on impinging the work surface that penetrates the inter-electrode gap and acts as a single-phase dielectric medium between the electrodes. It also effectively removes the debris particles from the discharge zone. Single-discharge EDM experiments are performed using ii three different dielectric supply methods, viz., conventional Wet-EDM (electrodes submerged in dielectric medium), Dry-EDM and Spray-EDM in order to compare the processes based on material removal, tool electrode wear and flushing of debris from the inter-electrode gap across a range of discharge energies. It is observed that Spray-EDM produces higher material removal compared to the other two methods for all combinations of discharge parameters used in the study.The tool electrode wear using atomized dielectric is significantly better than Dry-EDM and comparable to that observed in Wet-EDM. The percentage of debris particles deposited within a distance of 100 µm from the center of EDM crater is also significantly reduced using the Spray-EDM technique. iv

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“…gas atomization of molten metal has become a widely-used process for metal powder manufacturing [1][2][3][4][5], and it is also a critical process of spray forming technology [6][7][8], in both of which ultrafine and spherical droplets with a narrow size distribution are desired. During the atomization process, the gas field plays a crucial role in determining the size distribution of the droplets obtained after melt's break-up, making it an important part of gas atomization researches.…”

Section: Introductionmentioning

confidence: 99%

Archives of Metallurgy and Materials

Liu

Zhou

2021

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Numerical iNvestigatioN oN the gas Field geNerated by high Pressure gas atomizer Focused oN Physical mechaNisms oF gas recirculatioN aNd Wake closure PheNomeNoN Physical mechanisms of gas recirculation and wake closure were investigated by modeling the gas field generated by high Pressure gas atomizer using computational fluid dynamics. a recirculation mechanism based on axial and radial gas pressure gradient was proposed to explain the gas recirculation. The occurrence of wake closure is regarded as a natural result when elongated wake is gradually squeezed by expansion waves of increasing intensity. an abrupt drop could be observed in the numerical aspiration pressure curve, which corresponds well with the experimental results. The axial gradient of gas density is considered as the reason that results in the sudden decrease in aspiration pressure when wake closure occurs. Lastly, it is found that a shorter protrusion length and a smaller melt tip diameter would lead to a smaller wake closure pressure, which could benefit the atomizer design to produce fine metal powder with less gas consumption.

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Modeling of gas flow inside and outside the nozzle used in spray deposition

Cited by 14 publications

References 22 publications

Tool design effect on microlubrication spray efficiency in milling using inner channels

Tool design effect on microlubrication spray efficiency in milling using inner channels

Atomized Dielectric Spray-Based Electric Discharge Machining (Spray-EDM) for Sustainable Manufacturing

Archives of Metallurgy and Materials

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