Numerical study on the dynamics of an electrical discharge generated bubble in EDM

Shervani-Tabar, Mohammad T.; Abdullah, Amir; Shabgard, Mohammad Reza

doi:10.1016/j.enganabound.2006.01.014

Cited by 36 publications

(16 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…First, the workpiece move downward (decrease of the discharge gap) and second, the workpiece moves upward (increase of the discharge gap). By the decrease in the discharge gap, the pressure of discharge channel increases [15] which leads to the increase of the pressure gradient and flushing efficiency of the plasma channel at the end of discharge [17,18], and causes more molten material to be ejected away from the molten crater by the collapse of plasma channel.…”

Section: Methodsmentioning

confidence: 98%

Ultrasonic assisted EDM: Effect of the workpiece vibration in the machining characteristics of FW4 Welded Metal

et al. 2011

View full text Add to dashboard Cite

This paper presents the results of experimental studies carried out to conduct a comprehensive investigation on the influence of ultrasonic vibration of workpiece on the characteristics of Electrical Discharge Machining (EDM) process of FW4 Welding Metal in comparison with the conventional EDM process. The studied process characteristics included the material removal rate (MRR), tool wear ratio (TWR), and surface roughness (R a and R max ) of the workpiece after the EDM and ultrasonic assisted EDM (US-EDM) processes. The experiments performed under the designed full factorial procedure and the considered EDM input parameters included pulse ontime and pulse current. The experimental results show that in short pulse on-times, material removal rate in the US-EDM process is approximately quadruple than that of the EDM process. On the contrary, in the long pulse on-times, ultrasonic vibration of workpiece leads to the reduction in the MRR. On the other hand, in short pulse on-times, the TWR in the US-EDM process is lower than that of in the EDM process, and this condition reverses with increase in the pulse on-time. Furthermore, the surface roughness of the workpiece machined by EDM process is slightly lower than that of applied to the US-EDM process.

show abstract

Section: Methodsmentioning

confidence: 98%

Ultrasonic assisted EDM: Effect of the workpiece vibration in the machining characteristics of FW4 Welded Metal

et al. 2011

View full text Add to dashboard Cite

show abstract

“…When a high‐voltage electric spark discharge is applied to the electrodes, it creates a dielectric breakdown of the liquids between the electrodes and then induces localized hot plasma. Consequently, a cavitation microbubble is generated by liquid vaporization . The rapid expanding microbubble produces a high‐speed liquid jet flow, which will be focused by the nozzle to give a short mechanical shock in the main channel.…”

Section: Methodsmentioning

confidence: 99%

Spark‐generated microbubble cell sorter for microfluidic flow cytometry

Zhao

You

2018

Cytometry Pt A

View full text Add to dashboard Cite

High-speed and accurate cell sorting is of great significance for cell analysis regarding both bioresearch and clinical application. Different from the jet-in-air sorting of commercial flow cytometers, sorting in fully enclosed and disposal microfluidic chips can avoid aerosols and crosscontamination, thus contributing to the improvement of biosafety and test accuracy. However, current microfluidic sorters usually require complicated structures, or otherwise cannot attain high throughput. In this article, a sorting mechanism for microfluidics is proposed for the first time based on the jet flow induced by the spark-generated cavitation microbubble that can be easily realized by a pair of electrodes. The sorter was integrated into a microfluidic chip based on three-dimensional (3D) hydrodynamic focusing and a binary optical element (BOE) for laser illumination. Besides, several aspects of the sorting mechanism were studied to optimize the device. It achieved a switching time of 250 μs at the sample flow velocity of 5 m/s and performed the continuous operation at 200 Hz. Both the stability of fluorescence signals and the viability of cells were basically maintained. To conclude, this work explores a new on-chip sorting mechanism which possesses the merits of simple structure, easy control, and fast switching. © 2018 International Society for Advancement of Cytometry.

show abstract

“…Shervani-Tabar et al [12] conducted numerical analysis on the discharge bubble dynamics and showed the bubble was squeezed at the end of the discharge by the surrounding dielectric fluid and impinged on the melt pool. Hockenberry and Williams [13] experimentally studied the discharge bubble dynamics using a highspeed photography and suggested that the material removal was induced by the impingement of the liquid dielectric jets at the end of the discharge.…”

Section: Introductionmentioning

confidence: 99%

Modeling of the Anode Crater Formation in Electrical Discharge Machining

Jia

Shih

2012

Journal of Manufacturing Science and Engineering

View full text Add to dashboard Cite

This research presents a numerical model and the experimental validation of the anode crater formation in electrical discharge machining (EDM) process. The modeling is based on the theory that the material removal process in EDM is composed of two consecutive phases: the plasma heating phase in which intensive thermal energy density is applied locally to melt the work-material and the bubble collapsing phase in which the fluidic impact expels the molten material. A mathematical heat source model with Gaussian distributed heat flux and time variant heating area is applied in the plasma heating phase. Standard modules of a commercial computational fluid dynamics software, fluent, are adapted to model the crater formation in EDM. The material melting is simulated using transient heat transfer analysis and an enthalpy balance method. The volume of fraction (VOF) method is used to tackle the multiphase interactions in the processes of bubble compression and collapsing and molten material splashing and resolidification. Crater and debris geometries are attained from the model simulation and validation experiments are conducted to compare the crater morphology. The simulation and experiment results at different discharge conditions show good agreement on crater diameter suggest that the model is able to describe the mechanism of EDM crater formation.

show abstract

Numerical study on the dynamics of an electrical discharge generated bubble in EDM

Cited by 36 publications

References 4 publications

Ultrasonic assisted EDM: Effect of the workpiece vibration in the machining characteristics of FW4 Welded Metal

Ultrasonic assisted EDM: Effect of the workpiece vibration in the machining characteristics of FW4 Welded Metal

Spark‐generated microbubble cell sorter for microfluidic flow cytometry

Modeling of the Anode Crater Formation in Electrical Discharge Machining

Contact Info

Product

Resources

About