{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,3]],"date-time":"2026-04-03T02:49:47Z","timestamp":1775184587102,"version":"3.50.1"},"reference-count":53,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2020,11,16]],"date-time":"2020-11-16T00:00:00Z","timestamp":1605484800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>This article lists some tips for reducing gear case noise. With this aim, a static analysis was carried out in order to describe how stresses resulting from meshing gears affect the acoustic emissions. Different parameters were taken into account, such as the friction, material, and lubrication, in order to validate ideas from the literature and to make several comparisons. Furthermore, a coupled Eulerian\u2013Lagrangian (CEL) analysis was performed, which was an innovative way of evaluating the sound pressure level of the aforementioned gears. Different parameters were considered again, such as the friction, lubrication, material, and rotational speed, in order to make different research comparisons. The analytical results agreed with those in the literature, both for the static analysis and CEL analysis\u2014for example, it was shown that changing the material from steel to ductile iron improved the gear noise, while increasing the rotational speed or the friction increased the acoustic emissions. Regarding the CEL analysis, air was considered a perfect gas, but its viscosity or another state equation could have also been taken into account. Therefore, the above allowed us to state that research into these scientific fields will bring about reliable results.<\/jats:p>","DOI":"10.3390\/e22111306","type":"journal-article","created":{"date-parts":[[2020,11,16]],"date-time":"2020-11-16T11:04:20Z","timestamp":1605524660000},"page":"1306","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["Noise Reduction in Spur Gear Systems"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0972-3809","authenticated-orcid":false,"given":"Aurelio","family":"Liguori","sequence":"first","affiliation":[{"name":"Degree Course in Transport, University \u201cG. Fortunato\u201d, Viale Raffaele Delcogliano, 12, 82100 Benevento, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3511-6121","authenticated-orcid":false,"given":"Enrico","family":"Armentani","sequence":"additional","affiliation":[{"name":"Department of Chemical, Materials and Production Engineering, University of Naples \u201cFederico II\u201d, Piazzale V. Tecchio, 80, 80125 Napoli (NA), Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alcide","family":"Bertocco","sequence":"additional","affiliation":[{"name":"Department of Chemical, Materials and Production Engineering, University of Naples \u201cFederico II\u201d, Piazzale V. Tecchio, 80, 80125 Napoli (NA), Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5841-6661","authenticated-orcid":false,"given":"Andrea","family":"Formato","sequence":"additional","affiliation":[{"name":"Department of Agricultural Science, University of Naples \u201cFederico II\u201d, Via Universit\u00e0 100, 80045 Portici (NA), Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Arcangelo","family":"Pellegrino","sequence":"additional","affiliation":[{"name":"Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6545-4589","authenticated-orcid":false,"given":"Francesco","family":"Villecco","sequence":"additional","affiliation":[{"name":"Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,11,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1115\/1.3259012","article-title":"A Hydrodynamic Analysis of Fluid Flow Between Meshing Spur Gear Teeth","volume":"111","author":"Wittbrodt","year":"1989","journal-title":"J. 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