Zveza strojnih inženirjev in tehnikov Slovenije etc., = Association of Mechanical Engineers and Technicians of Slovenia etc.
Abstract
Računalniški modeli vozil za simuliranje trkov vedno natančneje opisujejo obnašanje resničnih vozil. Rezervoar za gorivo je eden izmed elementov vozil, katerega računalniški modeli so bili do sedaj zelo poenostavljeni. Takšni modeli upostevajo le vztrajnost mase goriva, ki je z masnimi točkami pritrjenana steno rezervoarja, vendar pa je vpliv gibanja goriva v rezervoarju popolnoma zanemarjen. Prispevek opisuje nove računalniske modele, s katerimi je mogoče simulirati deformacijo rezervoarja za gorivo ob upoštevanju gibanja goriva pri trku vozila. V ta namen so bile vrednotene štiri metode simuliranje gibanja tekočine (Lagrange, Euler, poljubnostna Lagrange-Eulerjeva metoda - PLE in hidrodinamika zglajenih delcev - HZD) v rezervoarju preproste oblike, analizirane z eksplicitnim programom LS-DYNA. Računalniski rezultati so bili primerjani s poprej objavljenimi preizkusnimi opazovanji, pri čemer je bila ugotovljena zelo dobra primerljivost med rezultati. Najprimernejsi metodi (HZD in PLE) sta bili kasneje uporabljeni v dinamičnih simulacijah dejanskega rezervoarja za gorivo. Simulacije so pokazale, da predstavljeni modeli rezervoarja ob upostevanju gibanja goriva zagotavljajo mnogo natančnejše rezultate v primerjavi z znanimi poenostavljenimi modeli.Computational models of vehicles for crash simulations are ever more precisely describing the behaviour of real vehicles. A fuel-tank is a typical vehicle element that has been very simplified in the computational models used so far. Such models have considered only the influence of the fuel mass inertia, which was point-wise connected to the tank walls, with total neglect of the fuel motion in the tank. This paper describes new computational models that allow for a simulation of the fuel-tank deformation considering the fuel motion during a vehicle crash. For this purpose four different methods for describing fluid motion (Lagrangian, Eulerian, Arbitrary Lagrange-Eulerian description - ALE, SPH) were evaluated on a simple reservoir problem, analysed with the explicit dynamic code LS-DYNA. The computational results were compared with previously published experimental observations and a good correlation of the results was observed. The most appropriate methods, SPH and ALE, were afterwards used in dynamic simulations of a real fuel-tank. The simulations showed that by also taking into consideration the fuel motion, the proposed computational models provide more accurate results in comparison with the previously used, simplified models
