57 KB613 KB56 KB199920252004Boltežar, MihaFurlan, Martin14 straništevilka:2letnik:50str. 115-128ISSN:0039-2480COBISSID:7335451URN:URN:NBN:SI:doc-8FWPVKHVenslAssociation of Mechanical Engineers and Technicians of Slovenia et al.Zveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikakustikadinamika strukturhrupmetoda robnih elementovmetode robnih elementovzvočno poljeMetoda robnih elementov v akustiki - primer ovrednotenja zvočnega polja enosmernega elektromotorja| The boundary-element method in acoustics - an example of evaluating the sound field of a DC electric motor|This paper presents a basic approach to solving exterior acoustic problems using the boundary-element method (BEM) and the development of a BEM program for solving three-dimensional (3D) problems. It also shows the integration of the developed BEM program into a finite-element method (FEM) program, which isprimarily used to evaluate the structural response that generates a sound field, but can also be used to pre-process and post-process the acoustic model. The program was verified by using an acoustic problem for which the analytical solution was already known. The verification was performed by researching the influence of the discretization density on the accuracy of thenumerically defined sound field. In addition to this, we also evaluated thetime necessary to solve the problem and its system of linear equations, andrelated it to the method chosen for solving this system of linear equations. The program was applied to a real case where the sound field of a DC electric motor was calculated using the BEM. Based on the structural response of the DC electric motor that is the result of the harmonic excitation of magnetic forces, and was calculated with the FEM, we evaluated the sound field surrounding the DC electric motorV prispevku so predstavljeni osnovni prijemi za reševanje zunanjih akustičnih problemov z metodo robnih elementov (MRE) ter njena izvedba v programu za reševanje trirazsežnih problemov. Prikazana je tudi integracija programa v komercialni programski paket metode končnih elementov (MKE), ki osnovno rabi kot orodje za določitev strukturnega odziva oz. vzroka za zvočno polje, drugotno pa za pripravo in kasnejso obdelavo akustičnega modela. Program MRE je ovrednoten na akustičnem problemu, pri katerem je poznana analitična resitev. Sama overitev je izvedena s poudarkom na raziskavi vpliva gostote diskretizacije na natančnost izraeuna zvočnega polja. Poleg tega je zaradi narave numeričnega problema oz. sistema linearnih enačb, ki pri tem nastane, ovrednotena tudi hitrost reševanja problema glede na izbiro postopka reševanja sistema linearnih enačb. Prikazana je tudi uporaba izvedenega programa MRE na dejanskem primeru. Na podlagi strukturnega odziva enosmernega elektromotorja, ki smo ga dobili kot posledico harmonskega vzbujanja magnetnih sil z MKE, smo ovrednotili zvočno polje v okolici enosmernega elektromotorjaTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo