Introduction. The Karman-vortex street formed behind two-dimensional bluff bodies has attracted interest because of its beautiful flow pattern. It goes without saying that this beautifulness results from the alternative vortices regularly shed from the body. Vortex shedding induces aerodynamic force perpendicular to the mean flow. This force causing mechanical vibration of the model is accompan...

Reducing the added resistance in waves has become a crucial aspect of today’s ship design. The is traditionally considered proportional to square wave height. However, this assumption believed be only partly valid, and further investigations are required. In present study, experimental tests numerical simulations were carried out determine regular head DTC hull (the scale factor 135). analysis ...

Quentin Skinner is an intellectual historian known for his pioneering work on early-modern European political thought. He was educated at Bedford School and Gonville and Caius College, Cambridge. Author of such works as The Foundations of Modern Political Thought (1978) and Visions of Politics (2002) he served as the Regius Professor of History at the University of Cambridge, and currently as t...

Abstract The paper presents a proposal for formalised approach to hull shape optimisation with respect total resistance, by fine-tuning longitudinal volume distribution. An algorithm automated modification of the is presented, allowing varying sectional area distribution negligible influence on resulting displacement. Computational fluid dynamics (CFD) solver STAR-CCM+ and computer computer-aid...

The paper deals with the high-fidelity modeling and simulation of a powered parafoil-payload system with respect to its application in autonomous precision airborne cargo delivery. In the proposed concept the cargo transfer is accomplished in two phases: Initial towing phase when the glider follows the towing vessel in a passive lift mode and the autonomous gliding phase when the system is guid...

Experimental testing of physical turbines, often at a smaller scale, is an essential tool for engineers to investigate fundamental design parameters such as power output and efficiency. Despite issues with scaling blockage which are caused by limitations in size flow velocity the test facilities, experimental tank laboratory environments perceived offering more control thus trustworthier result...

This paper presents the design and experimental results of a new type developable added bulbous bow that has been designated as dihedral bow. is based on polyhedral bows are used in small vessels, whose origin traced to 1990s. The designed with set surfaces following previous methodology surface considers material properties can contain boundary curves. Two designs their towing tank tests prese...

Abstract A bulbous bow is a widely employed feature to enhance the hydrodynamic resistance of ships. More than 95% merchant fleet incorporates various types bows reduce wave-making and wave breaking. Bulbous also utilized in smaller vessels like fishing vessels. In certain cases, initial ship design includes addition by default. this study, which focuses on typical Argentinian trawler vessel, w...

Hull roughness increases ship frictional resistance and, thus, results in economic and environmental penalties. Its effect has been prevalently predicted using the similarity law scaling procedure. However, this method not yet validated with experimental data a model ship. This study presents an investigation into of on provides validation scaling, by tank testing flat plate Both were tested sm...

Propulsion noise is an enduring problem of significant military and environmental importance. Hence, it crucial to investigate propeller characteristics. In this study, the hydrodynamic performance level DARPA (Defense Advanced Research Projects Agency) Suboff submarine with E1619 were analyzed. The hull resistance hydrodynamics studied separately, numerical results validated using available ex...