{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T00:35:47Z","timestamp":1781483747036,"version":"3.54.1"},"reference-count":27,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2020,2,2]],"date-time":"2020-02-02T00:00:00Z","timestamp":1580601600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51866007"],"award-info":[{"award-number":["51866007"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Gansu Provincial Natural Science Foundation","award":["17JR5RA092"],"award-info":[{"award-number":["17JR5RA092"]}]},{"name":"Collaborative Innovation Team Project of Gansu Province","award":["2018C-13"],"award-info":[{"award-number":["2018C-13"]}]},{"name":"Foundation of a hundred youth talents training program of Lanzhou Jiaotong University","award":["15022"],"award-info":[{"award-number":["15022"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>The effect of transverse pitch between a pair of delta-winglet vortex generators arranged in a common flow down configuration on the symmetrical flow structure and heat-transfer performance was numerically investigated. The results showed that symmetrical longitudinal vortices form a common flow down region between the vortices. The fluid is induced to flow from the top towards the bottom of the channel in the common flow region, which is advantageous to the heat transfer of the bottom fin. The vortex interaction increases and the vortex intensity decreases along with the decrease in transverse pitch of vortex generators. Vortex interaction has a slight influence on pressure penalty. The Nusselt number decreases with increasing vortex interaction. The vortices gradually attenuate and depart from each other during the process of flowing downward. A reasonable transverse pitch of delta-winglet vortex generators in a common-flow-down configuration is recommended for high thermal performance.<\/jats:p>","DOI":"10.3390\/sym12020209","type":"journal-article","created":{"date-parts":[[2020,2,3]],"date-time":"2020-02-03T01:25:51Z","timestamp":1580693151000},"page":"209","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Characteristics of Flow Symmetry and Heat Transfer of Winglet Pair in Common Flow Down Configuration"],"prefix":"10.3390","volume":"12","author":[{"given":"KeWei","family":"Song","sequence":"first","affiliation":[{"name":"School of Mechanical Engineering, Key Laboratory of Railway Vehicle Thermal Engineering of MOE, Lanzhou Jiaotong University; Lanzhou 730070, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"WeiNa","family":"Shi","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Key Laboratory of Railway Vehicle Thermal Engineering of MOE, Lanzhou Jiaotong University; Lanzhou 730070, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiang","family":"Wu","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Key Laboratory of Railway Vehicle Thermal Engineering of MOE, Lanzhou Jiaotong University; Lanzhou 730070, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"LiangBi","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Key Laboratory of Railway Vehicle Thermal Engineering of MOE, Lanzhou Jiaotong University; Lanzhou 730070, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,2,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Yanagihara, J.I., and Torri, K. (1991). Enhancement of laminar boundary layer heat transfer by longitudinal vortices. Transport Phenomena in Heat and Mass Transfer, Elsevier Science.","DOI":"10.1016\/B978-0-444-89851-7.50030-3"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.expthermflusci.2016.11.002","article-title":"Effect of geometric size of curved delta winglet vortex generators and tube pitch on heat transfer characteristics of fin-tube heat exchanger","volume":"82","author":"Song","year":"2017","journal-title":"Exp. Therm. Fluid Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.applthermaleng.2011.09.001","article-title":"CFD applications in various heat exchangers design: A review","volume":"32","author":"Hayat","year":"2012","journal-title":"Appl. Therm. Eng."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1129","DOI":"10.1016\/j.applthermaleng.2016.10.018","article-title":"A hybrid method for the cross flow compact heat exchangers design","volume":"111","author":"Starace","year":"2017","journal-title":"Appl. Therm. Eng."},{"key":"ref_5","first-page":"498","article-title":"Numerical analysis on the characteristic of turbulent heat transfer with multilongitudinal vortices in tube","volume":"3","author":"Meng","year":"2005","journal-title":"J. Eng. Thermophys."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2895","DOI":"10.1016\/j.enconman.2011.03.002","article-title":"Impact of delta winglet vortex generators on the performance of a novel fin-tube surface with two rows of tubes in different diameters","volume":"52","author":"Wu","year":"2011","journal-title":"Energy Convers. Manag."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"041902","DOI":"10.1115\/1.4023037","article-title":"The effectiveness of secondary flow produced by vortex generators mounted on both surfaces of the fin to enhance heat transfer in a flat tube bank fin heat exchanger","volume":"135","author":"Song","year":"2013","journal-title":"J. Heat Transf."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1615\/JEnhHeatTransf.v16.i2.30","article-title":"Convective heat transfer and absolute vorticity flux along main flow in a channel formed by flat tube bank fins with vortex generators mounted on both fin surfaces","volume":"16","author":"Song","year":"2009","journal-title":"J. Enhanc. Heat Transf."},{"key":"ref_9","first-page":"94","article-title":"An investigation of the airside performance of fin and tube heat exchangers with delta-winglet","volume":"31","author":"Lei","year":"2010","journal-title":"J. Eng. Thermophys."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1016\/j.applthermaleng.2018.01.062","article-title":"Numerical simulation of heat transfer enhancement in a plate-fin heat exchanger using a new type of vortex generators","volume":"133","author":"Samadifar","year":"2018","journal-title":"Appl. Therm. Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"114343","DOI":"10.1016\/j.applthermaleng.2019.114343","article-title":"Thermo-hydraulic performance optimization of wavy fin heat exchanger by combining delta winglet vortex generators","volume":"163","author":"Luo","year":"2019","journal-title":"Appl. Therm. Eng."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"298","DOI":"10.1016\/j.applthermaleng.2018.01.012","article-title":"Experimental and numerical study and comparison of performance for wavy fin and a plain fin with radiantly arranged winglets around each tube in fin and-tube heat exchangers","volume":"133","author":"Li","year":"2018","journal-title":"Appl. Therm. Eng."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1016\/j.ijthermalsci.2018.11.002","article-title":"Heat transfer characteristics of concave and convex curved vortex generators in the channel of plate heat exchanger under laminar flow","volume":"137","author":"Song","year":"2019","journal-title":"Int. J. Therm. Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1064","DOI":"10.1016\/j.ijheatmasstransfer.2019.03.072","article-title":"Numerical study on the flow and heat transfer characteristics in a dimple cooling channel with a wedge-shaped vortex generator","volume":"136","author":"Yang","year":"2019","journal-title":"Int. J. Heat Mass Transf."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"113790","DOI":"10.1016\/j.applthermaleng.2019.113790","article-title":"Longitudinal vortex generator applied to heat transfer enhancement of a flat plate solar water heater","volume":"158","author":"Silva","year":"2019","journal-title":"Appl. Therm. Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"119171","DOI":"10.1016\/j.ijheatmasstransfer.2019.119171","article-title":"Numerical investigation towards implementation of punched winglet as vortex generator for performance improvement of a fin-and-tube heat exchanger","volume":"149","author":"Gupta","year":"2020","journal-title":"Int. J. Heat Mass Transf."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1101","DOI":"10.1016\/j.solener.2018.05.093","article-title":"Thermal performance in solar air heater with perforated-winglet-type vortex generator","volume":"170","author":"Skullong","year":"2018","journal-title":"Sol. Energy"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1016\/j.ijheatmasstransfer.2012.10.034","article-title":"Effects of different orientations of winglet arrays on the performance of plate-fin heat exchangers","volume":"57","author":"Sinha","year":"2013","journal-title":"Int. J. Heat Mass Transf."},{"key":"ref_19","first-page":"2128","article-title":"Heat transfer enhancement in a channel with longitudinal VGs and field synergy principle analysis","volume":"12","author":"Tian","year":"2008","journal-title":"J. Eng. Thermophys."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"6332","DOI":"10.1016\/j.ijheatmasstransfer.2008.07.001","article-title":"Numerical investigation of fluid flow and heat transfer characteristics by common-flow-up","volume":"51","author":"Yang","year":"2008","journal-title":"Int. J. Heat Mass Transf."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"528","DOI":"10.1016\/j.applthermaleng.2017.01.106","article-title":"Effect of winglet location on heat transfer of a fin-and-tube heat exchanger","volume":"116","author":"Sarangi","year":"2017","journal-title":"Appl. Therm. Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1054","DOI":"10.1016\/j.ijheatmasstransfer.2018.07.148","article-title":"Analysis on heat transfer and pressure drop of fin-and-oval-tube heat exchangers with tear-drop delta vortex generators","volume":"127","author":"Lu","year":"2018","journal-title":"Int. J. Heat Mass Transf."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1016\/j.ijheatmasstransfer.2015.10.001","article-title":"Interaction of counter rotating longitudinal vortices and the effect on fluid flow and heat transfer","volume":"93","author":"Song","year":"2016","journal-title":"Int. J. Heat Mass Transf."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1016\/j.ijthermalsci.2018.06.011","article-title":"The optimal arrangement of vortex generators for best heat transfer enhancement in flat-tube-fin heat exchanger","volume":"132","author":"Song","year":"2018","journal-title":"Int. J. Therm. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1016\/j.ijthermalsci.2016.06.011","article-title":"Effects of longitudinal vortex interaction on periodically developed flow and heat transfer of fin-and-tube heat exchanger","volume":"109","author":"Song","year":"2016","journal-title":"Int. J. Therm. Sci."},{"key":"ref_26","unstructured":"Tao, W.Q. (2001). Numerical Heat Transfer, Xi\u2019an Jiaotong University Press. [2nd ed.]."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.icheatmasstransfer.2008.10.018","article-title":"Numerical study of fluid flow and heat transfer in a flat-plate channel with longitudinal vortex generators by applying field synergy principle analysis","volume":"36","author":"Tian","year":"2009","journal-title":"Int. Commun. Heat Mass Tran."}],"container-title":["Symmetry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-8994\/12\/2\/209\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T08:53:52Z","timestamp":1760172832000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-8994\/12\/2\/209"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,2,2]]},"references-count":27,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2020,2]]}},"alternative-id":["sym12020209"],"URL":"https:\/\/doi.org\/10.3390\/sym12020209","relation":{},"ISSN":["2073-8994"],"issn-type":[{"value":"2073-8994","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,2,2]]}}}