2,824 research outputs found
Experimental Investigation on Resistance and Vertical Motions on a medum Speed Catamaran with Central Bulbs
No full textIt has been demonstrated [1, 2, 3] that a central bulb placed between the demihulls of a catamaran hull reduces its vertical motions and, partly, its resistance. Previous investigations made by the Author regarded a fast catamaran hull (FN : 0.4 – 0.8). with wedge hull lines and central bulbs placed in different longitudinal and vertical positions. In this paper a new catamaran hull, with faired lines, has been examined on a velocity interval defined by FN : 0.2 – 0.6. A 1:19 scale model was built and tested in resistance and seakeeping tests in regular waves at the towing of Trieste University.
The original model without bulbs and in three different bulb configurations has been tested and examined. The results obtained outline the efficiency of these solutions, to improve the seakeeping criterion of catamaran hulls, without reducing their speed, although the bulb efficiency is more effective at higher speeds, close to FN = 0.6
Hydrodynamic Improvements of Catamaran Hulls when using Streamlined Bodies of Revolution
No full text
L'Ondogeno della Vasca di Trieste
No full textThe Wave Making Machine of the Towing Tank of Trieste
A short description is made of the wave-making machine that the laboratories of Naval Architecture Institute are equipped with, including a description of its peculiaritie
Prove sperimentali di stabilità di rotta su un modello di chiatta a traino
No full textExperimental Path Keeping Tests on a towed Barge Model
First we explain the basic principles of path keeping of a ship, then we go through the tank tests carried out at our laboratory in the University of Trieste.
These tests concern a barge towed by a tug and various devices we used to improve its efficiency. After a short investigation of the results obtained with the tank tests performed in a traditional way, we suggest a different and very easy experimental method suitable for towed bodies
Criteria proposed in Venice to assess the Wash Impact on the Environment and to Design Low-Wash Hull Configurations
No full textSistemi alternativi per il trasporto di merci con chiatte
No full textIl trasporto costiero e d’altura di contenitori e carichi alla rinfusa può esser intrapreso facendo uso di sistemi a traino o a spinta formati da chiatte e rimorchiatori, diversamente accoppiati. Si riportano e si analizzano i risultati ottenuti con esperienze eseguite alla vasca su modelli di chiatte e rimorchiatori, provati in diverse condizioni di reciproca connessione e si propongono alfine le soluzioni ritenute più idonee alla navigazione
A Method to predict the Wave Resistance of Planing Hulls, from a moving Hull Pressure Distribution
No full textA method for estimating the wave resistance in planing and semi-planing hulls will be presented. This prediction method calculates the wave resistance from a distribution of surfaces pressures acting over the free water surface and uses the calculation methods, currently applied for the ACV (air-cushion vehicle). Starting from an original paper by G.E. Gadd [1], in which the Author calculated the far field wave pattern for fast boats, the wave resistance is calculated for high speed vehicles by assuming an appropriate hull pressure distribution; then a practical application is presented
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