{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T13:13:47Z","timestamp":1783430027676,"version":"3.54.6"},"reference-count":36,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,6,20]],"date-time":"2026-06-20T00:00:00Z","timestamp":1781913600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Italian National Recovery and Resilience Plan (NRRP) of Next Generation EU","award":["PE00000001\u2014RESTART"],"award-info":[{"award-number":["PE00000001\u2014RESTART"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>This study presents a transient computational fluid dynamics (CFD) analysis of dielectric flow behaviour and debris transport in micro-EDM milling, considering the effects of dielectric properties, inter-electrode gap (IEG) size (20\u201330 \u00b5m), and tool rotational speed (400\u2013850 rpm). Four dielectric media, nitrogen gas, deionized water, HEDMA111 EDM oil, and sunflower seed oil, were investigated using a two-dimensional FEM-based model coupled with particle tracking simulations to evaluate debris mobility within the machining region. The results demonstrate that dielectric properties, particularly viscosity, strongly influence hydrodynamic behaviour and particle transport within the IEG. Under the adopted equal mass flow rate condition, nitrogen gas exhibited the highest flow velocities and the fastest debris evacuation due to the combined effects of its low viscosity and the resulting higher inlet velocity. Deionized water and HEDMA111 oil exhibit comparable intermediate behaviour, indicating that moderate viscosity variations within liquid dielectrics do not significantly alter the overall flow regime. In contrast, sunflower seed oil generates the most damped flow conditions, with reduced velocities and prolonged particle residence due to increased viscous resistance. Variations in IEG size produce only minor changes in evacuation efficiency compared with the dominant influence of dielectric properties, while tool rotational speed primarily affects velocity magnitude without altering qualitative transport behaviour.<\/jats:p>","DOI":"10.3390\/mi17060747","type":"journal-article","created":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T12:06:43Z","timestamp":1783426003000},"page":"747","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Flow Behaviour of Liquid and Gaseous Dielectrics and Debris Transport in the Inter-Electrode Gap of Micro-EDM Milling: A CFD Study"],"prefix":"10.3390","volume":"17","author":[{"given":"Mohammad","family":"Bigdeli","sequence":"first","affiliation":[{"name":"Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing, National Research Council of Italy-STIIMA-CNR, Via P. Lembo 38\/F, 70124 Bari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4025-645X","authenticated-orcid":false,"given":"Francesco Giovanni","family":"Modica","sequence":"additional","affiliation":[{"name":"Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing, National Research Council of Italy-STIIMA-CNR, Via P. Lembo 38\/F, 70124 Bari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5499-2389","authenticated-orcid":false,"given":"Valeria","family":"Marrocco","sequence":"additional","affiliation":[{"name":"Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing, National Research Council of Italy-STIIMA-CNR, Via P. Lembo 38\/F, 70124 Bari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6144-2123","authenticated-orcid":false,"given":"Irene","family":"Fassi","sequence":"additional","affiliation":[{"name":"Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing, National Research Council-STIIMA-CNR, Via A. Corti 12, 20133 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Modica, F., Marrocco, V., and Fassi, I. (2017). Micro-Electro-Discharge Machining (Micro-EDM). 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