1979 KB22 KB199920252014Koc, Pinoštevilka:3letnik:60str. 203-209, SI 37ISSN:0039-2480COBISSID:13401627URN:URN:NBN:SI:doc-BJGS0XP3enZveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikjadrniceračunalniške simulacijeteleskopske dvižne kobilicevetrni valoviSea-wave dynamic loading of sailing yacht's retractable keel|A highly specialized analysis of functionality of a retractable keel lifting mechanism is presented in the paper. Because of its special design a retractable keel is vulnerable to rough sea conditions. To alleviate possible malfunctions or even damage to the keel, an analysis of lifting the keel during rough sea (WMO sea state 6) is performed. Reliable estimation of load acting on a keel is crucial for the subsequent functional or structural analysis of the keel. Aiming to obtain these loads, a sea wave analysis is performed first, where a wave train is determined by respecting statistical data regarding the required sea condition. Two wave cases are considered: head seas (waves coming from the front) and beam seas (lateral waves). A deterministic dynamic analysis on the wave-hull-keel system is then performed. The response of this system is obtained in the form of a time dependent acceleration of the centre of gravity of the vessel and in a time dependent lifting force, i.e., the force which is required for lifting the moveable part of the keel during rough sea. Finally, the required pulling force of the lifting mechanism is determinedKobilica na sodobnih jadrnicah je oblikovana v obliki navpično stoječega krila simetričnega prereza, ki sega globoko pod trup jadrnice. Običajno je na spodnjem koncu krila dodana še utež, prav tako hidrodinamično oblikovana, s katero zmanjšujejo nagib jadrnice, ki je posledica delovanja sile vetra na jadra. Globoko segajoča kobilica in utež je seveda primerna za jadranje, obenem pa onemogoča vplutje v plitkejše zalive in pristanišča. Z namenom ohranjanja obeh zaželjenih lastnosti, t.j., kvalitetnih jadralskih sposobnosti in dostopnosti v plitkejše vode, so razvili različne vrste dvižnih kobilic. Poseben tip dvižnih kobilic je t.i. teleskopska kobilica, ki je pritrjena na trup s spodnje strani in, za razliko od običajnih dvižnih kobilic, katerih dvižni jašek zaseda znaten del bivalnega dela v trupu jadrnice, ne sega v notranjost trupaTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo