Ανάπτυξη και Εφαρμογή Μεθόδου Δίσκου Ορμής και Φέρουσας Γραμμής σε Εulerian Επιλυτή για την Προσομοίωση Ναυτικών Ελίκων

Ευσταθιάδης, Βασίλειος-Χρήστος; Efstathiadis, Vasileios-Christos

dc.contributor.author	Ευσταθιάδης, Βασίλειος-Χρήστος	el
dc.contributor.author	Efstathiadis, Vasileios-Christos	en
dc.date.accessioned	2023-05-17T10:25:25Z
dc.date.available	2023-05-17T10:25:25Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/57719
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.25416
dc.rights	Default License
dc.subject	Υπολογιστική Ρευστοδυναμική,	el
dc.subject	Δυναμικές Ροές	el
dc.subject	Ναυτικές Έλικες	el
dc.subject	Θεωρία Φέρουσας Γραμμής	el
dc.subject	Θεωρία Δίσκου Ορμής	el
dc.subject	Μέθοδο Πεπερασμένων Όγκων	el
dc.subject	CFD	en
dc.subject	URANS	en
dc.subject	Lifting Line	en
dc.subject	Actuator Disk	en
dc.title	Ανάπτυξη και Εφαρμογή Μεθόδου Δίσκου Ορμής και Φέρουσας Γραμμής σε Εulerian Επιλυτή για την Προσομοίωση Ναυτικών Ελίκων	el
dc.title	Development and Implementation of an Actuator Disk and Lifting Line Method Coupled with an Eulerian Solver for Hydrodynamic Simulation of Μarine Propellers	en
dc.contributor.department	Ναυτική και Θαλάσσια Τεχνολογία	el
heal.type	masterThesis
heal.classification	Computational Fluid Dynamics	en
heal.language	el
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2022-07-13
heal.abstract	In computational fluid dynamics (CFD), hydrodynamic simulations are performed to investigate the inflow characteristics hence the hydrodynamic forces developed on marine propeller surfaces during its interaction with the ship's hull. The most common practice for determining these forces is to solve the Unsteady Reynolds Averaged Navier - Stokes equations (URANS). However, sufficient spatial discretization of individual solid boundaries significantly increases computational costs. Alternatively, the coupling of (URANS) with simplified numerical methods is often adopted, where the URANS methodology is used to simulate the flow around the hull of the ship, while inviscid solvers are used for the flow around the propeller. Under the same scope, the present thesis aims to develop two hybrid numerical methods capable of simulating the hydrodynamic behaviour of a marine propeller in open water conditions and in the absence of solid boundaries. Particularly, an Actuator Disc method is developed based on Goldstein's research (1929) for Optimum circulation distributions and a Lifting Line method based on Betz's condition of normality (1919), horseshoe vortex theory as well as Wrench’s closed-form approximations (1957). The coupling of the two methods with the incompressible Eulerian Solver (MaPFlow) is achieved by integrating source terms to the momentum equations. The Actuator Disk method uses uniform volumetric forces to project the forces onto the grid, while the Lifting Line method uses Gaussian distributions or an Actuator Disk as an interface with the computational cells. Firstly, the validation of the Lifting Line Method is evaluated through the comparison of the numerical findings with experimental data for three marine propellers. Afterwards, the axial induced velocity fields are examined to verify the two numerical approaches. In order to validate their prediction capability, one blade passage of the fully resolved KVLCC KP458 propeller is modelled using periodic boundary conditions. The computational simulations that take place concern a plethora of advance coefficients for all ranges of loading both in steady and unsteady flow conditions. As to the LL, as an isolated numerical tool, it is deemed successful in the estimation of the hydrodynamic characteristics with a satisfactory agreement of the experimental data for all test cases. All in all, regarding the evaluation of hybrid methods, the ability of the implemented numerical methods to provide a fast and satisfactory estimation of the induced velocity fields is demonstrated, significantly reducing the required computational cost.	en
heal.advisorName	Παπαδάκης, Γεώργιος	el
heal.committeeMemberName	Μπελιμπασάκης, Κωνσταντίνος	el
heal.committeeMemberName	Γρηγορόπουλος, Γρηγόριος	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Ναυπηγών Μηχανολόγων Μηχανικών	el
heal.academicPublisherID	ntua
heal.numberOfPages	87 σ.	el
heal.fullTextAvailability	false