Experimental investigation of the effect of superhydrophobic coating and microbubble lubrication on the resistance of a scaled ship model

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dc.contributor.author Lee, Paul en
dc.date.accessioned 2020-05-26T13:46:56Z
dc.date.available 2020-05-26T13:46:56Z
dc.identifier.uri https://dspace.lib.ntua.gr/xmlui/handle/123456789/50658
dc.identifier.uri http://dx.doi.org/10.26240/heal.ntua.18356
dc.rights Default License
dc.subject Drag reduction en
dc.subject Microbubble lubrication en
dc.subject Superhydrophobic coating en
dc.subject Ship resistance en
dc.title Experimental investigation of the effect of superhydrophobic coating and microbubble lubrication on the resistance of a scaled ship model en
heal.type bachelorThesis
heal.classification Hydrodynamics en
heal.classification Marine Engineering en
heal.language en
heal.access free
heal.recordProvider ntua el
heal.publicationDate 2019-09-16
heal.abstract Skin friction of a fluid flowing near a solid surface poses many problems in variety applications. Increased energy consumption in marine and aerospace vehicles and decreased performances in hydraulic systems are one of the major issues to name a few. Thus, reduction of frictional drag leads to obvious technological advantages from an engineering perspective with additional economical and environmental benefits. Various studies and intense research have been conducted by the scientific community in order to propose effective ways to reduce frictional drag. Few of the many techniques are the reduction of resistance through super water repellent coatings, also known as superhydrophobic, and microbubble injection in the boundary layer. In this thesis, the effectiveness of the aforementioned techniques is tested experimentally by comparing the total resistance of a ship model with and without the introduction of microbubbles under the condition of a superhydrophobic coated surface in order to examine the performance difference between them. The flat of bottom of a 2.52 [m] long ship model is treated with a special nano-ceramic coating and a microbubble generator attached on the stem is able to produce fine bubbles of 50 [μm] diameter. The total resistance is recorded at towing speeds of 1.5, 2.0, and 2.5 [m/s], at an even keel and 0.5o trim by stern condition, and a maximum of 4.5% reduction of the frictional coefficient is noted. This paper is divided into four chapters. The 1st chapter provides an introduction to the skin friction problem in maritime, a literature review, and a proposal of an experimental concept. Chapter 2 provides details of the microbubble generator and its setup while chapter 3 presents the implementation of the experimental concept and necessary optimizations. Analysis of the measurements data are presented in the last chapter with final notes. en
heal.advisorName Triantafyllou, George en
heal.committeeMemberName Triantafyllou, George en
heal.committeeMemberName Gregory, Grigoropoulos en
heal.committeeMemberName Papadakis, George en
heal.academicPublisher Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Ναυπηγών Μηχανολόγων Μηχανικών. Τομέας Ναυτικής και Θαλάσσιας Υδροδυναμικής. Εργαστήριο Ναυτικής και Θαλάσσιας Υδροδυναμικής el
heal.academicPublisherID ntua
heal.numberOfPages 56 σ.
heal.fullTextAvailability false

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