{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,9]],"date-time":"2026-01-09T20:30:48Z","timestamp":1767990648192,"version":"3.49.0"},"reference-count":35,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2019,3,8]],"date-time":"2019-03-08T00:00:00Z","timestamp":1552003200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100013276","name":"Interreg","doi-asserted-by":"publisher","award":["EAPA_198\/2016"],"award-info":[{"award-number":["EAPA_198\/2016"]}],"id":[{"id":"10.13039\/100013276","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Energies"],"abstract":"<jats:p>Micro-hydro systems can be used as a promising new source of renewable energy generation, requiring a low investment cost of hydraulic, mechanical, and electrical equipment. The improvement of the water management associated with the use of pumps working as turbines (PATs) is a real advantage when the availability of these machines is considered for a wide range of flow rates and heads. Parallel turbomachines can be used to optimize the flow management of the system. In the present study, experimental tests were performed in two equal PATs working in parallel and in single mode. These results were used to calibrate and validate the numerical simulations. The analysis of pressure variation and head losses was evaluated during steady state conditions using different numerical models (1D and 3D). From the 1D model, the installation curve of the system was able to be defined and used to calculate the operating point of the two PATs running in parallel. As for the computational fluid dynamics (CFD) model, intensive analysis was carried out to predict the PATs\u2032 behavior under different flow conditions and to evaluate the different head losses detected within the impellers. The results show system performance differences between two units running in parallel against a single unit, providing a greater operational flow range. The performance in parallel design conditions show a peak efficiency with less shock losses within the impeller. Furthermore, by combining multiple PATs in parallel arrangement, a site\u2019s efficiency increases, covering a wide range of applications from the minimum to the maximum flow rate. The simulated flow rates were in good agreement with the measured data, presenting an average error of 10%.<\/jats:p>","DOI":"10.3390\/en12050901","type":"journal-article","created":{"date-parts":[[2019,3,8]],"date-time":"2019-03-08T04:58:35Z","timestamp":1552021115000},"page":"901","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["Flow Conditions for PATs Operating in Parallel: Experimental and Numerical Analyses"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1783-543X","authenticated-orcid":false,"given":"Mariana","family":"Sim\u00e3o","sequence":"first","affiliation":[{"name":"Department of Civil Engineering, Architecture and Georesources (DECivil) and CEris member, Instituto Superior T\u00e9cnico, University of Lisbon, 1049-001 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8316-7778","authenticated-orcid":false,"given":"Modesto","family":"P\u00e9rez-S\u00e1nchez","sequence":"additional","affiliation":[{"name":"Hydraulic and Environmental Engineering Department, Universitat Polit\u00e8cnica de Val\u00e8ncia, 46022 Valencia, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0414-9913","authenticated-orcid":false,"given":"Armando","family":"Carravetta","sequence":"additional","affiliation":[{"name":"Department of Hydraulic, Geotechnical and Environmental Engineering, Universit\u00e0 di Napoli Federico II, via Claudio, 21, Napoli 80125, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9028-9711","authenticated-orcid":false,"given":"Helena M.","family":"Ramos","sequence":"additional","affiliation":[{"name":"Department of Civil Engineering, Architecture and Georesources (DECivil) and CEris member, Instituto Superior T\u00e9cnico, University of Lisbon, 1049-001 Lisboa, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,3,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Ismail, M.A., Othman, A.K., Islam, S., and Zen, H. 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