Ανάπτυξη λογισμικού προσομοίωσης της λίπανσης
μεταξύ των δαχτυλιδιών πιστονιού/χιτωνίου μηχανής
εσωτερικής καύσης

Λιόση, Αλεξάνδρα-Ιωάννα; Liosi, Alexandra-Ioanna

dc.contributor.author	Λιόση, Αλεξάνδρα-Ιωάννα	el
dc.contributor.author	Liosi, Alexandra-Ioanna	en
dc.date.accessioned	2021-03-30T17:55:22Z
dc.date.available	2021-03-30T17:55:22Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/53215
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.20913
dc.rights	Αναφορά Δημιουργού-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights	Αναφορά Δημιουργού-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by-nd/3.0/gr/	*
dc.subject	Επιφανειακή τραχύτητα, Χιτώνιο, Δαχτυλίδια εμβόλου, Τριβολογία, Μοντέλο υπολογιστικής ρευστοδυναμικής	el
dc.subject	Tribology, Cylinder liner, Piston ring-pack, Surface texture, CFD modelling	en
dc.title	Ανάπτυξη λογισμικού προσομοίωσης της λίπανσης μεταξύ των δαχτυλιδιών πιστονιού/χιτωνίου μηχανής εσωτερικής καύσης	el
dc.title	Development of a simulation tool for the lubrication between the piston rings and the cylinder bore of an internal combustion engine	en
heal.type	bachelorThesis
heal.classification	Computational fluid dynamics	en
heal.classification	Tribology	en
heal.language	el
heal.language	en
heal.access	campus
heal.recordProvider	ntua	el
heal.publicationDate	2021-02
heal.abstract	For decreasing power losses during the operation of a reciprocating Internal Combustion Engine, the inner cylinder wall undergoes surface ﬁnishing. This diploma thesis proposes a combination for the cylinder bore’s surface characteristics, that leads to lower friction losses. Also, it prepares the ground for performing a gradient-free or gradient-based optimization, by developing a major part of the required tools. This tribological analysis is based on the lubrication between the piston, its top ring and the cylinder wall. The steady-state Navier-Stokes equations are solved for the laminar ﬂow of an incompressible lubricant in the hydrodynamic lubrication regime, in the OpenFOAM environment. The liner’s surface topography is introduced as a pat- tern of triangular grooves with base dimensions in µm. For this reason, the complete cylinder’s stroke isn’t simulated. The pressure and velocity boundary conditions are selected for a speciﬁc crank angle and rotational speed. A framework is used for quickly creating the necessary geometry ﬁles, which include diﬀerent ring proﬁles and alternative liner features. Though an adequate sampling of the design space and evaluation on the CFD tool of the selected samples, it is proposed for the bore’s surface ﬁnish to create deep grooves in close proximity. Additionally, a comparison between the results of the fundamental velocity-driven and pressure-driven ﬂows, in fully-ﬂooded condition, in simpliﬁed geometries and the frequently used Reynolds equation is made. Lastly, the analysis is extended by extracting the unsteady ﬂow equations in multiple frames of reference for this kind of simulations.	en
heal.sponsor	Major part of this work was carried out in midst a 6-month long internship, at the premises of Toyota Motor Europe in Brussels.	el
heal.advisorName	Giannakoglou, Kyriakos C.	en
heal.advisorName	Gkagkas, Konstantinos	en
heal.committeeMemberName	Αρετάκης, Νικόλαος	el
heal.committeeMemberName	Μαθιουδάκης, Κωνσταντίνος	el
heal.committeeMemberName	Γιαννάκογλου, Κυριάκος Χ.	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Μηχανολόγων Μηχανικών. Τομέας Ρευστών. Εργαστήριο Θερμικών Στροβιλομηχανών	el
heal.academicPublisherID	ntua
heal.numberOfPages	124 σ.	el
heal.fullTextAvailability	false