{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T08:31:28Z","timestamp":1773822688119,"version":"3.50.1"},"reference-count":30,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2020,9,25]],"date-time":"2020-09-25T00:00:00Z","timestamp":1600992000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/EMS\/50022\/2019"],"award-info":[{"award-number":["UID\/EMS\/50022\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UIDB\/50022\/2020"],"award-info":[{"award-number":["UIDB\/50022\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["SFRH\/BD\/140009\/2018"],"award-info":[{"award-number":["SFRH\/BD\/140009\/2018"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Applied Sciences"],"abstract":"<jats:p>In aero-engines, the introduction of biofuels is among the best alternatives to fossil fuels, and this change is likely to affect the impact of droplets on interposed surfaces. Under this framework, this work reviews the main morphological hydrodynamic structures occurring upon the impact of a liquid droplet on a wetted surface, using jet fuel and biofuel mixtures as alternative fuels. The experiments performed allow investigating the effect of the liquid film thickness on the dynamic behavior of single drop impact, considering the relevancy of these phenomena to the optimization of engine operating parameters. Particular emphasis is given to the occurrence of crown splash, and the morphological differences in the outcomes of drop impact depending on the impact conditions and fluid properties. The four fluids tested included pure water (as reference), 100% Jet A-1, 75%\/25%, and 50%\/50% mixtures of Jet A-1 and NExBTL (Neste Renewable Diesel)\u2014with the Weber impact number between 103 and 1625; Reynolds values 1411\u201316,889; and dimensionless film thicknesses of \u03b4 = 0.1, 0.5, and 1. The analysis on the secondary atomization for the different fluids evidences the predominance of prompt and crown splash, and jetting for alternative fuels. Finally, besides a systematic review of empirical correlations for the transition to splash, we investigate their universality by extrapolating the validation range to evaluate their ability to predict the outcome of impact accurately. One of the correlations studied show the highest degree of universality for the current experimental conditions, despite its limitation to thin liquid films (\u03b4=0.1).<\/jats:p>","DOI":"10.3390\/app10196698","type":"journal-article","created":{"date-parts":[[2020,9,25]],"date-time":"2020-09-25T08:57:32Z","timestamp":1601024252000},"page":"6698","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Insights into Single Droplet Impact Models upon Liquid Films Using Alternative Fuels for Aero-Engines"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5059-5303","authenticated-orcid":false,"given":"Daniela F. S.","family":"Ribeiro","sequence":"first","affiliation":[{"name":"AEROG, LAETA, Aeronautics and Astronautics Research Center, Universidade da Beira Interior, 6201-001 Covilh\u00e3, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4901-7140","authenticated-orcid":false,"given":"Andr\u00e9 R. R.","family":"Silva","sequence":"additional","affiliation":[{"name":"AEROG, LAETA, Aeronautics and Astronautics Research Center, Universidade da Beira Interior, 6201-001 Covilh\u00e3, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9561-9268","authenticated-orcid":false,"given":"Miguel R. O.","family":"Pan\u00e3o","sequence":"additional","affiliation":[{"name":"ADAI, LAETA, Associa\u00e7\u00e3o para o Desenvolvimento da Aerodin\u00e2mica Industrial, Universidade de Coimbra, 3030-788 Coimbra, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2020,9,25]]},"reference":[{"key":"ref_1","first-page":"155","article-title":"Outcomes from a drop impact on solid surfaces","volume":"11","author":"Rioboo","year":"2001","journal-title":"At. Sprays"},{"key":"ref_2","first-page":"13","article-title":"On the collision of a droplet with a solid surface","volume":"432","author":"Chandra","year":"1991","journal-title":"Proc. R. Soc. Lond. Ser. A Math. Phys. Sci."},{"key":"ref_3","unstructured":"Rioboo, R., Marengo, M., Cossali, G., and Tropea, C. (2000, January 11\u201313). Comparison of drop impact: Dry and wetted cases. Proceedings of the 16th International Conference On Liquid Atomisation and Spray Systems (ILASS), Darmstadt, Germany."},{"key":"ref_4","first-page":"550","article-title":"Development of methodology for spray impingement simulation","volume":"104","author":"Bai","year":"1995","journal-title":"SAE Trans."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"463","DOI":"10.1007\/s003480050073","article-title":"The impact of a single drop on a wetted solid surface","volume":"22","author":"Cossali","year":"1997","journal-title":"Exp. Fluids"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1615\/AtomizSpr.v10.i3-5.80","article-title":"Modeling of spray impact on solid surfaces","volume":"10","author":"Tropea","year":"2000","journal-title":"At. Sprays"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1007\/s00348-005-0045-1","article-title":"The splash\/non-splash boundary upon a dry surface and thin fluid film","volume":"40","author":"Berger","year":"2006","journal-title":"Exp. Fluids"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"518","DOI":"10.2151\/jmsj1965.55.5_518","article-title":"The physical products of a splashing water drop","volume":"55","author":"Stow","year":"1977","journal-title":"J. Meteorol. Soc. Jpn. Ser. II"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1016\/j.ijmultiphaseflow.2004.11.001","article-title":"Fluctuating flow in a liquid layer and secondary spray created by an impacting spray","volume":"31","author":"Roisman","year":"2005","journal-title":"Int. J. Multiph. Flow"},{"key":"ref_10","unstructured":"(2019). ASTM D1655-19a, Standard Specification for Aviation Turbine Fuels, ASTM International. Technical Report."},{"key":"ref_11","unstructured":"(2019). ASTM D7566-19b, Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons, ASTM International. Technical Report."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1378","DOI":"10.1016\/j.energy.2017.07.077","article-title":"Sustainable alternative fuels in aviation","volume":"140","author":"Yilmaz","year":"2017","journal-title":"Energy"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1501","DOI":"10.1007\/s13762-017-1528-3","article-title":"Impact of a Jet A-1\/HEFA blend on the performance and emission characteristics of a miniature turbojet engine","volume":"15","author":"Gawron","year":"2018","journal-title":"Int. J. Environ. Sci. Technol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"118321","DOI":"10.1016\/j.fuel.2020.118321","article-title":"A study of droplet deformation: The effect of crossflow velocity on jet fuel and biofuel droplets impinging onto a dry smooth surface","volume":"279","author":"Vasconcelos","year":"2020","journal-title":"Fuel"},{"key":"ref_15","unstructured":"Cossali, G., Brunello, G., Coghe, A., and Marengo, M. (1999). Impact of a Single Drop on a Liquid Film: Experimental Analysis and Comparison with Empirical Models, Italian Congress of Thermofluid Dynamics UIT."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"888","DOI":"10.1007\/s00348-003-0772-0","article-title":"The role of time in single drop splash on thin film","volume":"36","author":"Cossali","year":"2004","journal-title":"Exp. Fluids"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1349","DOI":"10.1063\/1.1652061","article-title":"On some common features of drop impact on liquid surfaces","volume":"16","author":"Fedorchenko","year":"2004","journal-title":"Phys. Fluids"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1006\/jcis.1998.5518","article-title":"Influence of surface roughness on liquid drop impact","volume":"203","author":"Range","year":"1998","journal-title":"J. Colloid Interface Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1007\/s00348-005-0044-2","article-title":"Droplets splashing upon films of the same fluid of various depths","volume":"40","author":"Berger","year":"2006","journal-title":"Exp. Fluids"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2155","DOI":"10.1063\/1.1287511","article-title":"Splashing impact of a single drop onto very thin liquid films","volume":"12","author":"Wang","year":"2000","journal-title":"Phys. Fluids"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1007\/s00348-005-0043-3","article-title":"The combined influence of a rough surface and thin fluid film upon the splashing threshold and splash dynamics of a droplet impacting onto them","volume":"40","author":"Berger","year":"2006","journal-title":"Exp. Fluids"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"554","DOI":"10.1016\/j.pecs.2010.01.002","article-title":"Advances and challenges in explaining fuel spray impingement: How much of single droplet impact research is useful?","volume":"36","author":"Moreira","year":"2010","journal-title":"Prog. Energy Combust. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Zhang, Y., Liu, P., Qu, Q., Liu, F., and Agarwal, R.K. (2017, January 9\u201313). Numerical Simulation of a Droplet Impacting upon Films with Varied Liquid Properties. Proceedings of the 55th AIAA Aerospace Sciences Meeting, Grapevine, TX, USA.","DOI":"10.2514\/6.2017-1468"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1540","DOI":"10.1039\/C7SM02089A","article-title":"Impact of droplets on immiscible liquid films","volume":"14","author":"Che","year":"2018","journal-title":"Soft Matter"},{"key":"ref_25","first-page":"202","article-title":"Droplet splashing on thin moving films at high Weber numbers","volume":"101","author":"Burzynski","year":"2018","journal-title":"Energy"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.ijheatmasstransfer.2016.10.031","article-title":"Review of drop impact on heated walls","volume":"106","author":"Liang","year":"2017","journal-title":"Int. J. Heat Mass Transf."},{"key":"ref_27","unstructured":"Ribeiro, D.F.S. (2018). Experimental Study of a Single Droplet Impinging upon Liquid Films: Jet Fuel and Biofuel Mixtures. [Master\u2019s Thesis, University of Beira Interior]."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Tropea, C., and Marengo, M. (1999). The impact of drops on walls and films. Multiph. Sci. Technol., 11.","DOI":"10.1615\/MultScienTechn.v11.i1.20"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"3963","DOI":"10.1063\/1.323218","article-title":"Splashing of drops on liquid layers","volume":"47","author":"Macklin","year":"1976","journal-title":"J. Appl. Phys."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1798","DOI":"10.1063\/1.1708605","article-title":"Crater depth in fluid impacts","volume":"37","author":"Engel","year":"1966","journal-title":"J. Appl. Phys."}],"container-title":["Applied Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3417\/10\/19\/6698\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:13:30Z","timestamp":1760177610000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3417\/10\/19\/6698"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,9,25]]},"references-count":30,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2020,10]]}},"alternative-id":["app10196698"],"URL":"https:\/\/doi.org\/10.3390\/app10196698","relation":{},"ISSN":["2076-3417"],"issn-type":[{"value":"2076-3417","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,9,25]]}}}