{"id":18842,"date":"2025-02-13T12:58:35","date_gmt":"2025-02-13T12:58:35","guid":{"rendered":"https:\/\/aerospacerepository.org\/?p=18842"},"modified":"2025-02-13T12:58:36","modified_gmt":"2025-02-13T12:58:36","slug":"effect-of-external-stores-aerodynamics-on-analytic-fighter-aircraft-flutter-predictions-evaluation-of-a-superposition-modeling-approach","status":"publish","type":"post","link":"https:\/\/aerospacerepository.org\/index.php\/2025\/02\/13\/effect-of-external-stores-aerodynamics-on-analytic-fighter-aircraft-flutter-predictions-evaluation-of-a-superposition-modeling-approach\/","title":{"rendered":"EFFECT OF EXTERNAL STORES AERODYNAMICS ON ANALYTIC FIGHTER AIRCRAFT FLUTTER PREDICTIONS: EVALUATION OF A SUPERPOSITION MODELING APPROACH"},"content":{"rendered":"\n<p><strong>Maj. Michael Iovnovich<\/strong><\/p>\n\n\n\n<p><strong>DOI Number: N\/A<\/strong><\/p>\n\n\n\n<p><strong>Conference number: IFASD-2019-045<\/strong><\/p>\n\n\n\n<p>Flutter instability prediction of \ufb01ghter aircrafts capable of carrying an extensive external stores inventory typically requires analytic assessment of thousands of con\ufb01gurations throughout the operational \ufb02ight envelope. To enable realistic solution times, simpli\ufb01ed unsteady aerodynamics models are commonly used, in which underwing stores aerodynamics is neglected. In the current study, the effects of underwing stores aerodynamics on \ufb02utter prediction capabilities are assessed using a heavyweight store con\ufb01guration of the F-16 aircraft with multiple underwing stores and in correlation with \ufb02ight test data. This examination is conducted at the high transonic \ufb02ow regime using two unsteady aerodynamics solvers, namely, the linear, panel-based ZAERO solver and the nonlinear, Euler, ZEUS solver. This investigation showed that underwing stores modeling may in-fact considerably affect the predicted \ufb02utter onset speeds. Neglecting stores aerodynamics yielded both less realistic and nonconservative predictions by both ZAERO and ZEUS models. The comparison between the ZAERO and ZEUS models solutions revealed signi\ufb01cant differences in steady and unsteady surface pressure distributions due to nonlinear \ufb02ow phenomena. These differences also manifested in signi\ufb01cant distinctions between the two models \ufb02utter predictions. To enable full aerodynamic modeling in industrial \ufb02utter survey applications, a superposition modeling approach is formulated and successfully validated using the studied test case. According to this method, introduction of a new store into the aircraft weapons inventory will only require a single aerodynamic model solution, then aerodynamic models for con\ufb01gurations including any permutation of the new store with other pre-existing stores in the database may be directly assembled with no additional computations required. This technique is found effective for superposition between linearized unsteady aerodynamics stores effects, even if the base \ufb02ow of these effects is nonlinear. However, once interference between stores becomes dominant and nonlinear, this modeling approach is no longer valid.<\/p>\n\n\n\n<p><a href=\"https:\/\/aerospacerepository.org\/wp-content\/uploads\/2025\/02\/IFASD-2019-045.pdf\">Read the full paper here<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p><b>Maj. Michael Iovnovich<\/b><\/p>\n<p>DOI Number: N\/A<\/p>\n<p>Conference number: IFASD-2019-045<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2433,2452],"tags":[1998,2273,1304,2001],"class_list":["post-18842","post","type-post","status-publish","format-standard","hentry","category-1-ifasd-2019","category-reduced-order-models","tag-computational-aeroelasticity","tag-flutter-analysis","tag-reduced-order-modeling","tag-unsteady-aerodynamics","category-2433","category-2452","description-off"],"_links":{"self":[{"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/posts\/18842","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=18842"}],"version-history":[{"count":1,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/posts\/18842\/revisions"}],"predecessor-version":[{"id":18846,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/posts\/18842\/revisions\/18846"}],"wp:attachment":[{"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/media?parent=18842"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/categories?post=18842"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aerospacerepository.org\/index.php\/wp-json\/wp\/v2\/tags?post=18842"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}