Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Powiadomienia systemowe

Sesja wygasła!

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: towing tank test

Sortuj według:

Ogranicz wyniki do:

Vessel energy requirement prediction from acceleration stage towing tests on scale models

Wrzask Klaudia

Polish Maritime Research

2023

nr 2

4--10

One of the most crucial tasks for naval architects is computing the energy required to meet the ship’s operational needs. When predicting a ship’s energy requirements, a series of hull resistance tests on a scale model vessel is carried out in constant speed stages, while the acceleration stage measurements are ignored. Another important factor in seakeeping analysis is the ship’s hydrodynamic added mass. The second law of dynamics states that all this valuable information, that is, the dependence of the hull resistance on the vessel’s speed and the added mass, is accessible from just one acceleration stage towing test done up to the maximum speed. Therefore, the acceleration stage, often overlooked in traditional towing experiments, can be a valuable source of information. For this reason, this work aims to generalise Froude’s scaling procedure to full-scale vessels for the accelerated stage towing tests.

The hydrodynamic resistance of stepped planing hulls under different geometrical and physical conditions

Najafi Amin, Nowruzi Hashem, Salari Mahmoud, Kazemi Hamid

Zeszyty Naukowe Akademii Morskiej w Szczecinie

2019

nr 58 (130)

24--31

In this paper, the hydrodynamic resistance of one-step planing craft has been experimentally investigated under different geometrical and physical conditions. For this to be accomplished, a Fridsma body model with different deadrise angles was considered. Moreover, the effect of the longitudinal distance of the step from the transom and the step height on the hydrodynamic resistance of a stepped planing craft has been evaluated at different hull velocities. According to the experimental results, frictional resistance can be enhanced by decreasing the height of the step. However, a greater total resistance can be obtained by increasing the longitudinal distance of the step from the transom. Moreover, it was found that the proportionality of the longitudinal distance of the step from the transom to the step height has a remarkable effect on the hydrodynamic efficiency of the step in stepped planing craft.

Rewizja przybliżonych metod obliczania oporu całkowitego kadłuba z wykorzystaniem badań modelowych wybranego jachtu żaglowego

Malinowska A., Karczewski A., Pruszko H.

Prace Wydziału Nawigacyjnego Akademii Morskiej w Gdyni

2018

Z. 33

42--52

Rewizja opiera się na weryfikacji wybranych przybliżonych metod prognozowania oporu całkowitego gołego kadłuba, opracowanych w wyniku badań systematycznej serii kadłubów jachtów żaglowych w latach 1973–2010, znanych jako The Delft Systematic Yacht Hull Series (DSYHS). Zademonstrowano wyniki otrzymane z wykorzystaniem wzorów przybliżonych (Metoda Delft), obliczeń numerycznych (CFD) i badań modelowych dla wybranego jachtu żaglowego o nowoczesnym kształcie kadłuba wraz z ich dyskusją.

The revision is based on the verification of approximate methods of the prediction of the total resistance of the bare hull developed in the results of a systematic study of a series sailboat hulls from 1973 to 2010 known as The Delft Systematic Yacht Hull Series (DSYHS). Demonstrations were obtained based on approximate formulas (Delft method), numerical calculations (CFD) and the towing tank test for a selected sailing yacht with a modern hull shape along with a discussion of results.