Problémy pri výpočtovom modelovaní interakcie piestu a valca

Difficulties in Computational Modelling of Piston/Liner Interaction

conference paper

en

From the very beginning of the piston dynamic behavior investigation, the engineers tended to use experimental methods and compare them with very simple calculations. However, the experimental tests did show some serious difficulties that needed to be managed in order to obtain reasonable results, e.g. separation of vibrations due to piston slap motion, signal destroyed by combustion process, etc. This is the reason why the test rigs were hardly able to provide detailed insights into the piston dynamics, since it could be lost in a plethora of interactive physical phenomena. Therefore, the focus was, gradually, aimed at the computational models, which were (and still are) much faster, but need to be compared with experimental results to ensure the adequacy of algorithms used. This paper discusses the difficulties and uncertainties occurring during the construction of such computational model.

Od začiatku vyšetrovania dynamického správania piestu sa inžinieri uchyľovali k experimentálnym metódam a porovnávali ich s veľmi jednoduchými výpočtami. Výsledky experimentov vykazovali niekoľko závažných problémov, ktoré museli byť vyriešené za účelom získania rozumných výsledkov ako napr. separácia vibrácií spôsobených klopením piesta, signál znehodnotený spaľovacím procesom a iné. To je dôvod prečo testovacie zariadenia len ťažko dokázali ponúknuť náhľad do detailov dynamického chovania piestu, pretože sa mohli stratiť v množstve doprovodných fyzikálnych dejov. Preto bola pozornosť postupne zameriavaná na výpočtové modely, ktoré boli (a stále sú) omnoho rýchlejšie, ale vyžadujú porovnávanie s experimentálnymi výsledkami kvôli posúdeniu vhodnosti použitých algoritmov. Tento príspevok sa zaoberá problémami a neistotami, ktoré sa objavujú pri vývoji takého výpočtového modelu.

From the very beginning of the piston dynamic behavior investigation, the engineers tended to use experimental methods and compare them with very simple calculations. However, the experimental tests did show some serious difficulties that needed to be managed in order to obtain reasonable results, e.g. separation of vibrations due to piston slap motion, signal destroyed by combustion process, etc. This is the reason why the test rigs were hardly able to provide detailed insights into the piston dynamics, since it could be lost in a plethora of interactive physical phenomena. Therefore, the focus was, gradually, aimed at the computational models, which were (and still are) much faster, but need to be compared with experimental results to ensure the adequacy of algorithms used. This paper discusses the difficulties and uncertainties occurring during the construction of such computational model.

elastohydrodrodynamické mazanie, mechanické straty, multibody dynamics, tribológia

elastohydrodynamic lubrication, mechanical loss, multibody dynamics, tribology

31.08.2016

JVE International Ltd.

Kaunas, Lithuania

2345-0533

Vibroengineering PROCEDIA

7

1

134–137

4