{"id":18696,"date":"2024-11-20T12:22:58","date_gmt":"2024-11-20T12:22:58","guid":{"rendered":"https:\/\/aerospacerepository.org\/?p=18696"},"modified":"2024-11-20T12:22:58","modified_gmt":"2024-11-20T12:22:58","slug":"the-aeroelastic-impact-of-engine-thrust-and-gyroscopics-on-aircraft-flutter-instabilities","status":"publish","type":"post","link":"https:\/\/aerospacerepository.org\/index.php\/2024\/11\/20\/the-aeroelastic-impact-of-engine-thrust-and-gyroscopics-on-aircraft-flutter-instabilities\/","title":{"rendered":"The Aeroelastic Impact of Engine Thrust and Gyroscopics on Aircraft Flutter Instabilities"},"content":{"rendered":"\n<p><strong>Stefan Waitz, Holger Hennings<\/strong><\/p>\n\n\n\n<p><strong>DOI Number: N\/A<\/strong><\/p>\n\n\n\n<p><strong>Conference number: IFASD-2015-192<\/strong><\/p>\n\n\n\n<p>Since more and more modern civil aircraft are equipped with UHBR-engines for reasons of fuel e\ufb03ciency and environmental aspects, the need to tackle speci\ufb01c engine related dynamic problems has occurred. The request for UHBR-engines with high bypass ratio numbers and with their intrinsic advantages of economic fuel consumption and lower acoustic emission asks for enhanced vibration prediction capabilities. Beside the energetic bene\ufb01ts such engines add to the aircraft design their rotating large diameter fans can in\ufb02uence the dynamic behaviour of the complete elastic aircraft fuselage in a very unfavourable manner. Additional questions which arise with regard to structural dynamics and aeroelastic stability are treated in this work. Especially in the scenario when large rotating engine masses are to be combined with elastic wing structures the possible occurrence of speci\ufb01c structural vibration problems can be avoided by taking the gyroscopic e\ufb00ects into account. As another important engine related aspect the modelling and the impact of the engine thrust is highlighted by integrating the \ufb01rst order deformation induced terms into the dynamical simulation model. By introducing an increased coupling level between the degrees of freedom in the equation of motion (through additional o\ufb00-diagonal terms) both eigenfrequencies and eigenmodes are a\ufb00ected. In the case of high engine participation in the structural deformation we can observe a lowering of the eigenfrequencies (in the test aeroplane up to 6[%]) and a loss in symmetry properties in the now strongly asymmetric eigenmodes. With the occurrence of \ufb02utter cases the critical speed had been experienced to shift about an amount of similar magnitude. Although in the presented cases the \ufb02utter speed moved to higher values, it was found indespensable to check every individual aircraft con\ufb01guration with regard to the stability margin.<\/p>\n\n\n\n<p><a href=\"https:\/\/aerospacerepository.org\/wp-content\/uploads\/2024\/11\/IFASD-2015-192.pdf\">Read the full paper here<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p><b>Stefan Waitz, Holger Hennings<\/b><\/p>\n<p>DOI Number: N\/A<\/p>\n<p>Conference number: IFASD-2015-192<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2413,2422],"tags":[681,2355,2358,2360,2357,975,2359,2356,2352],"class_list":["post-18696","post","type-post","status-publish","format-standard","hentry","category-1-ifasd-2015","category-aeroelastic-response-stability","tag-aerodynamic-damping","tag-asymmetric-eigenmode","tag-critical-speed","tag-engine-aeroelasticity","tag-engine-thrust","tag-flutter","tag-utter-frequency","tag-follower-force","tag-gyroscopics","category-2413","category-2422","description-off"],"_links":{"self":[{"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/posts\/18696","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=18696"}],"version-history":[{"count":1,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/posts\/18696\/revisions"}],"predecessor-version":[{"id":18698,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/posts\/18696\/revisions\/18698"}],"wp:attachment":[{"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/media?parent=18696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/categories?post=18696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/tags?post=18696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}