{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,20]],"date-time":"2025-12-20T22:15:56Z","timestamp":1766268956513,"version":"build-2065373602"},"reference-count":29,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2018,10,15]],"date-time":"2018-10-15T00:00:00Z","timestamp":1539561600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Instrumentation Program of China","award":["2013YQ040911"],"award-info":[{"award-number":["2013YQ040911"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51775446"],"award-info":[{"award-number":["51775446"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A flexible hot-film sensor array for wall shear stress, flow separation, and transition measurement has been fabricated and implemented in experiments. Parylene C waterproof layer is vapor phase deposited to encapsulate the sensor. Experimental studies of shear stress and flow transition on a flat plate have been undertaken in a water tunnel with the sensor array. Compared with the shear stress derived from velocity profile and empirical formulas, the measuring errors of the hot-film sensors are less than 5%. In addition, boundary layer transition of the flat plate has also been detected successfully. Ensemble-averaged mean, normalized root mean square, and power spectra of the sensor output voltage indicate that the Reynolds number when transition begins at where the sensor array located is 1.82 \u00d7 105, 50% intermittency transition is 2.52 \u00d7 105, and transition finishes is 3.96 \u00d7 105. These results have a good agreement with the transition Reynolds numbers, as measured by the Laser Doppler Velocimetry (LDV) system.<\/jats:p>","DOI":"10.3390\/s18103469","type":"journal-article","created":{"date-parts":[[2018,10,16]],"date-time":"2018-10-16T02:52:53Z","timestamp":1539658373000},"page":"3469","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["A Flexible Hot-Film Sensor Array for Underwater Shear Stress and Transition Measurement"],"prefix":"10.3390","volume":"18","author":[{"given":"Baoyun","family":"Sun","sequence":"first","affiliation":[{"name":"Key Laboratory of Micro\/Nano Systems for Aerospace, Ministry of Education, Northwestern Polytechnical University, Xi\u2019an 710072, Shaanxi, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2964-9378","authenticated-orcid":false,"given":"Pengbin","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Micro\/Nano Systems for Aerospace, Ministry of Education, Northwestern Polytechnical University, Xi\u2019an 710072, Shaanxi, China"}]},{"given":"Jian","family":"Luo","sequence":"additional","affiliation":[{"name":"Key Laboratory of Micro\/Nano Systems for Aerospace, Ministry of Education, Northwestern Polytechnical University, Xi\u2019an 710072, Shaanxi, China"}]},{"given":"Jinjun","family":"Deng","sequence":"additional","affiliation":[{"name":"Key Laboratory of Micro\/Nano Systems for Aerospace, Ministry of Education, Northwestern Polytechnical University, Xi\u2019an 710072, Shaanxi, China"}]},{"given":"Shiqi","family":"Guo","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, George Washington University, Washington, DC 20052, USA"}]},{"given":"Binghe","family":"Ma","sequence":"additional","affiliation":[{"name":"Key Laboratory of Micro\/Nano Systems for Aerospace, Ministry of Education, Northwestern Polytechnical University, Xi\u2019an 710072, Shaanxi, China"}]}],"member":"1968","published-online":{"date-parts":[[2018,10,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Schlichting, H., and Gersten, K. 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