24 research outputs found
Verification of the theoretical methods for the prediction of resistance of sailing yachts based on the towing tank test
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
Bifurcation of periodic solutions in differential inclusions
summary:Ordinary differential inclusions depending on small parameters are considered such that the unperturbed inclusions are ordinary differential equations possessing manifolds of periodic solutions. Sufficient conditions are determined for the persistence of some of these periodic solutions after multivalued perturbations. Applications are given to dry friction problems