20.500.12556/DKUM-79326 Numerična analiza vpliva geometrije zgorevalne predkomore na karakteristike zgorevanja pri bencinskih motorjih magistrsko delo Numerical analysis of prechamber geometry influence on combustion characteristics of gasoline engines Razvoj motorjev z notranjim zgorevanjem je močno pogojen s predpisi, ki določajo zgornjo mejo dovoljenih emisij. Znižanje emisij CO2 se doseže z izboljšano termodinamično učinkovitostjo, znižanje emisij NOx pa z znižanjem temperature. Ta pogoja si pogosto nasprotujeta. Ena izmed obetavnih tehnologij, ki se je že uveljavila v Formuli 1, je zgorevalna predkomora, bodisi v aktivni ali pasivni obliki. Z doseganjem večje površine vžiga, se poveča hitrost zgorevanja in posledično se zmanjša specifična poraba goriva. Za optimalno delovanje motorja je potrebno poznati geometrijske vplive predkomore na proces zgorevanja. V tej nalogi je predstavljenih šest variant pasivne predkomore, za katere so bile izvedene numerične simulacije računalniške dinamike tekočin s programskim paketom AVL FIRE. Na podlagi rezultatov teh simulacij, se je ovrednotil proces zgorevanja in zasnovala nova varianta geometrije. Na koncu je podana ocena variant, prav tako pa je izpostavljena najboljša. The development of internal combustion engines is largely influenced by normatives, that set an upper limit for emissions. The reduction of CO2 emissions is achieved by increased thermodynamic efficiency, while the reduction of NOx emissions depends on the decrease of the temperature. These requirements are often conflicting. A promising technology, which has already been adapted in Formula 1, is the combustion prechamber, of either the passive or active type. By increasing the surface of mixture ignition, the rate of heat release is also increased, resulting in improved specific fuel consumption. For optimum operating conditions of the engine, a thorough understanding of geometry influence on the combustion process is required. Six variants of passive prechambers are analyzed in this thesis, for which computational fluid dynamics simulations have been carried out using the AVL FIRE software package. Based on the results of these simulation, the combustion process has been evaluated and new geometry designs have been proposed. At the end of this work is an assessment of the variants, also highlighting the best one. Predkomora motor z notranjim zgorevanjem bencinski motor GDI računalniška dinamika tekočin zgorevanje AVL FIRE Prechamber Internal Combustion Engine GDI Computational Fluid Dynamics CFD Combustion AVL FIRE true true false [S. Bezenšek] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2021-06-14 10:16:08 2021-07-21 11:41:36 2022-08-09 20:25:49 0000-00-00 00:00:00 2021 0 Maribor 0 Maribor XII, 109 f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 621.434.05(043.2) 74610947 MAG_Bezensek_Simon_2021.pdf MAG_Bezensek_Simon_2021.pdf 1 81FF46FE6FC4C3AE170C45E4397E9727 c6f5e9b9cf40fa59a2d98d4640b8969a802349fd41d29cc081deaca05dd7d167 8ac9e39d-d9c9-11eb-b665-00155d581298 20.500.12556/dkum/87d8cb5b-2c6e-45b3-8326-f4cff1798ce3 https://dk.um.si/Dokument.php?lang=slv&id=151042 Fakulteta za strojništvo 0 0 0