{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T13:59:46Z","timestamp":1774619986314,"version":"3.50.1"},"reference-count":12,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2024,12,29]],"date-time":"2024-12-29T00:00:00Z","timestamp":1735430400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Council of Science, Technology, and Technological Innovation (CONCYTEC)","award":["PE501078609-2022-PROCIENCIA"],"award-info":[{"award-number":["PE501078609-2022-PROCIENCIA"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>This research aims to determine the primary thermofluidic correlations describing the thermosiphon effect under idealized steady-state conditions, considering water-in-glass evacuated-tube geometry, tilt angle, and heat flux. A numerical model based on Computational Fluid Dynamics (CFD) was developed to obtain these correlations for water-in-glass evacuated-tube solar collectors. Initial validation against experimental velocity and temperature profiles was necessary. With a validated CFD model, thermofluidic correlations were determined, expressed as dimensionless parameters such as Re, Gr, and Pr, water-in-glass evacuated-tube dimensions, and tilt angle. Symmetry was exploited in the water-in-glass evacuated-tube geometry for both validation simulations and the development of thermofluidic correlations. Contrary to correlations recorded in the literature, the correlations obtained in this study indicate an increase in water flow and a decrease in mean temperature with increasing tilt angle. These correlations are crucial for the energy\u2013exergy balance formulations used in the analysis and design of such thermal systems.<\/jats:p>","DOI":"10.3390\/sym17010044","type":"journal-article","created":{"date-parts":[[2024,12,31]],"date-time":"2024-12-31T13:26:25Z","timestamp":1735651585000},"page":"44","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Thermofluidics in Water-in-Glass Evacuated-Tube Solar Collectors Analysis Based on the Symmetry Conditions of Heat Flux and Tilt Angle"],"prefix":"10.3390","volume":"17","author":[{"given":"Elder M.","family":"Mendoza Orbegoso","sequence":"first","affiliation":[{"name":"Department of Mechatronic Engineering, National University of Trujillo, Trujillo 13011, Peru"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7068-9267","authenticated-orcid":false,"given":"Josmell Alva","family":"Alc\u00e1ntara","sequence":"additional","affiliation":[{"name":"Department of Mechatronic Engineering, National University of Trujillo, Trujillo 13011, Peru"}]},{"given":"Luis Julca","family":"Ver\u00e1stegui","sequence":"additional","affiliation":[{"name":"Department of Mechatronic Engineering, National University of Trujillo, Trujillo 13011, Peru"}]},{"given":"Juan Carlos","family":"Bengoa","sequence":"additional","affiliation":[{"name":"Department of Mechatronic Engineering, National University of Trujillo, Trujillo 13011, Peru"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4313-8398","authenticated-orcid":false,"given":"Daniel","family":"Marcelo-Aldana","sequence":"additional","affiliation":[{"name":"Department of Mechanical-Electrical Engineering, University of Piura, Piura 20009, Peru"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1767-3941","authenticated-orcid":false,"given":"Ra\u00fal","family":"La Madrid Olivares","sequence":"additional","affiliation":[{"name":"Department of Mechanical-Electrical Engineering, University of Piura, Piura 20009, Peru"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8466-356X","authenticated-orcid":false,"given":"Konstantinos G.","family":"Kyprianidis","sequence":"additional","affiliation":[{"name":"School of Business, Society and Engineering, M\u00e4lardalen University, 72220 V\u00e4ster\u00e5s, Sweden"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e15185","DOI":"10.1016\/j.heliyon.2023.e15185","article-title":"A comprehensive review of techniques for increasing the efficiency of evacuated tube solar collectors","volume":"9","author":"Aggarwal","year":"2023","journal-title":"Heliyon"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Murthy, M., Patil, Y., Ambekar, D., Patil, T., Sonawane, G., Chaudhari, R., Patil, G., Sharma, S., Polem, B., and Kolte, S. (2011, January 27\u201329). Concrete slab solar water heating system. Proceedings of the IEEE First Conference on Clean Energy and Technology (CET), Kuala Lumpur, Malaysia.","DOI":"10.1109\/CET.2011.6041486"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.solener.2003.07.024","article-title":"Water-in-glass evacuated tube solar water heaters","volume":"76","author":"Morrison","year":"2004","journal-title":"Sol. Energy"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.solener.2004.09.005","article-title":"Measurement and simulation of flow rate in a water-in-glass evacuated tube solar water heater","volume":"78","author":"Morrison","year":"2005","journal-title":"Sol. 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Energy"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"117331","DOI":"10.1016\/j.energy.2020.117331","article-title":"On the effect of storage tank type on the performance of evacuated tube solar collectors: Solar radiation prediction analysis and case study","volume":"198","author":"Sadeghi","year":"2020","journal-title":"Energy"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Marinca, V., and Herisanu, N. (2020). Construction of analytic solution to axisymmetric flow and heat transfer on a moving cylinder. Symmetry, 12.","DOI":"10.3390\/sym12081335"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Togun, H., Hamidatou, S., Mohammed, H., Abed, A., Hasan, H., Homod, R., Al-Fatlawi, A., Al-Thamir, M., and Abdulrazzaq, T. (2023). Numerical simulation on heat transfer augmentation by using innovative hybrid ribs in a forward-facing contracting channel. Symmetry, 15.","DOI":"10.3390\/sym15030690"},{"key":"ref_11","unstructured":"Urbano, E. (2020). 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[Ph.D. Thesis, University of New South Wales]."}],"container-title":["Symmetry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-8994\/17\/1\/44\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:56:01Z","timestamp":1760115361000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-8994\/17\/1\/44"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,12,29]]},"references-count":12,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,1]]}},"alternative-id":["sym17010044"],"URL":"https:\/\/doi.org\/10.3390\/sym17010044","relation":{},"ISSN":["2073-8994"],"issn-type":[{"value":"2073-8994","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,12,29]]}}}