{"id":17835,"date":"2024-08-14T12:21:23","date_gmt":"2024-08-14T12:21:23","guid":{"rendered":"https:\/\/aerospacerepository.org\/?p=17835"},"modified":"2024-08-16T09:20:59","modified_gmt":"2024-08-16T09:20:59","slug":"investigation-of-frequency-lock-in-phenomena-on-asupercritical-aerofoil-in-the-presence-of-transonicshock-oscillations","status":"publish","type":"post","link":"https:\/\/aerospacerepository.org\/index.php\/2024\/08\/14\/investigation-of-frequency-lock-in-phenomena-on-asupercritical-aerofoil-in-the-presence-of-transonicshock-oscillations\/","title":{"rendered":"INVESTIGATION OF FREQUENCY LOCK-IN PHENOMENA ON A SUPERCRITICAL AEROFOIL IN THE PRESENCE OF TRANSONIC SHOCK OSCILLATIONS"},"content":{"rendered":"\n<p><strong>Nicholas F. Giannelis, Gareth A. Vio<\/strong><\/p>\n\n\n\n<p><strong>DOI Number: N\/A<\/strong><\/p>\n\n\n\n<p><strong>Conference number: IFASD-2017-074<\/strong><\/p>\n\n\n\n<p>Within a narrow band of the transonic \ufb02ight regime, shock-wave\/boundary layer interactions yield large amplitude, self-sustained shock oscillations. When this transonic buffet instability interacts with a forced or freely oscillating structure, frequency lock-in between the aerodynamic and structural modes can occur, resulting in large amplitude limit cycle oscillations of the structure. In this study, the lock-in phenomenon is investigated by means of Reynolds-Averaged Navier-Stokes simulations. Harmonically driven pitching simulations are performed for a range of driving frequencies and amplitudes for the supercritical OAT15A aerofoil section. The results show that for a band of driving frequencies near the buffet, frequency synchronisation develops for suf\ufb01cient driving amplitudes. The \ufb02ow topology within the lockin regions differs for driving frequencies above and below the buffet. This is attributed to a phase reversal of the aerodynamic coef\ufb01cients as the excitation frequency passes through the fundamental \ufb02ow frequency. Analysis of the gain and phase relationships of the aerodynamic coef\ufb01cients supports the \ufb01ndings of prior studies, where the lock-in phenomenon is related to bounded single degree-of-freedom \ufb02utter.<\/p>\n\n\n\n<p><a href=\"https:\/\/aerospacerepository.org\/wp-content\/uploads\/2024\/08\/IFASD-2017-074.pdf\">Read the full paper here<\/a><\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p><b>Nicholas F. Giannelis, Gareth A. Vio<b\/><\/p>\n<p>DOI Number: N\/A<\/p>\n<p>Conference number: IFASD-2017-074<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[993,1957,1953],"tags":[2095,2094,2001],"class_list":["post-17835","post","type-post","status-publish","format-standard","hentry","category-events","category-computational-aeroelasticity","category-ifasd-2017","tag-frequency-lock-in","tag-transonic-shock-buffet","tag-unsteady-aerodynamics","category-993","category-1957","category-1953","description-off"],"_links":{"self":[{"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/posts\/17835","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/comments?post=17835"}],"version-history":[{"count":2,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/posts\/17835\/revisions"}],"predecessor-version":[{"id":17925,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/posts\/17835\/revisions\/17925"}],"wp:attachment":[{"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/media?parent=17835"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/categories?post=17835"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/tags?post=17835"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}