{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,23]],"date-time":"2025-10-23T11:09:05Z","timestamp":1761217745322,"version":"build-2065373602"},"reference-count":10,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2014,11,10]],"date-time":"2014-11-10T00:00:00Z","timestamp":1415577600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>The purpose of this article is to study the heat transfer characteristics of a  voice-coil and permanent magnet for a speaker using nano-sized ferrofluid. In order to investigate the temperature characteristics of the speaker, the speaker power ratings, ambient temperatures of the test chamber, chamber sizes and input signals were tested. As a result, the temperatures of the voice-coil and magnet for the speaker increased with time due to the thermal linearity. The temperature of the voice-coil increased with the decrease of the input signals, but with the increase of the nominal power rating. The voice-coil temperature of Speaker 1 using ferrofluid of an amount of 650 \u03bcL at an elapsed time of 10,000 s was 24.5% lower than that of general Speaker 1. In addition, the proper size selection of the enclosure is an important design factor to ensure the sound quality and effective heat transfer of the speaker.<\/jats:p>","DOI":"10.3390\/e16115891","type":"journal-article","created":{"date-parts":[[2014,11,10]],"date-time":"2014-11-10T12:23:05Z","timestamp":1415622185000},"page":"5891-5900","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Heat Transfer Characteristics of a Speaker Using  Nano-Sized Ferrofluid"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8857-4444","authenticated-orcid":false,"given":"Moo-Yeon","family":"Lee","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, Dong-A University, Busan 604-714, Korea"}]},{"given":"Hyung-Jin","family":"Kim","sequence":"additional","affiliation":[{"name":"Graduate school of Mechanical Engineering, Dong-A University, Busan 604-714, Korea"}]}],"member":"1968","published-online":{"date-parts":[[2014,11,10]]},"reference":[{"key":"ref_1","unstructured":"Oh, S.J. (2006). Fundamentals of Loudspeaker Engineering, Seok HakDang."},{"key":"ref_2","first-page":"93","article-title":"Befitting test of magnetic fluid to speaker damper","volume":"8","author":"Lee","year":"1998","journal-title":"J. Korean Magn. Soc"},{"key":"ref_3","first-page":"3","article-title":"Nonlinear modelling of the heat transfer in loudspeakers","volume":"52","author":"Klippe","year":"2004","journal-title":"J. Audio Eng. Soc"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"717","DOI":"10.1016\/S0003-682X(00)00064-5","article-title":"Loudspeaker failure modes and error correction techniques","volume":"62","author":"Hsu","year":"2001","journal-title":"Appl. Acoust"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1016\/j.enconman.2012.09.010","article-title":"Experimental study on forced thermoacoustic oscillation driven by loudspeaker","volume":"65","author":"Pan","year":"2013","journal-title":"Energy Convers. Manag"},{"key":"ref_6","unstructured":"Koh, S.J., Lee, K.J., Kang, J.H., Oh, G.H., Sung, K.H., and Kim, C.J. (2008, January 23). Development of a temperature prediction tool for voice-coils in loudspeakers using CFD analysis. Hang-Won, Korea."},{"key":"ref_7","unstructured":"Kim, H.J., Seo, J.H., Lee, W.Y., Yeom, J.K., and Lee, M.Y. (2013, January 22). Numerical simulation on heat transfer performance of the woofer speaker with the variation of voice-coil and bobbin structures. Seoul, Korea."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"166","DOI":"10.4283\/JKMS.2013.23.5.166","article-title":"Numerical analysis on temperature characteristics of the voice-coil for woofer speaker using ferrofluid","volume":"23","author":"Lee","year":"2013","journal-title":"J. Korean Magn. Soc"},{"key":"ref_9","first-page":"93","article-title":"Befitting test of magnetic fluid to speaker damper","volume":"8","author":"Lee","year":"1998","journal-title":"J. Korean Magn. Soc"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Lee, M.Y., and Seo, J.H. (2013). Numerical investigation on heat and flow characteristics of temperature-sensitive ferrofluid in a square cavity. Adv. Mech. Eng.","DOI":"10.1155\/2013\/240438"}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/16\/11\/5891\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:09:08Z","timestamp":1760216948000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/16\/11\/5891"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,11,10]]},"references-count":10,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2014,11]]}},"alternative-id":["e16115891"],"URL":"https:\/\/doi.org\/10.3390\/e16115891","relation":{},"ISSN":["1099-4300"],"issn-type":[{"type":"electronic","value":"1099-4300"}],"subject":[],"published":{"date-parts":[[2014,11,10]]}}}