Research objectives and contents A fundamental study on the motion of a liquid inside a partially filled tank (sloshing) is proposed, and main attention is focused on its naval concerns. In facts, ship oscillations, can often excite violent fluid motions which in turn lead to significant global loads as well as to highly localized forces, related to the impact of the water against the walls of the tank (slamming). Beside this, resonant sloshing flows can significantly affect the dynamics of the ship as a whole.
The main goal of the proposed activity is to develop a model and an effective numerical technique for describing sloshing flows and to compute the related hydrodynamic loads. To this purpose, a two-dimensional inviscid model will be adopted for studying the fluid motion inside arbitrary shaped smooth-tanks, subjected to irregular excitations. In particular, the strongly nonlinear free surface behaviour is of main concern and it will be analysed in time-domain by developing a highly refined boundary integral technique. Both the physical assumptions and the numerical model will be then validated by comparing the results with available analytical solutions and experimental data.
Also a description of those phenomena relevant to determine the fluid loads will be embodied in the model. In particular, the water impact on the walls (slamming) and the following localized loads will be analysed by generalizing the existing models. Simplified models will be developed for describing those dissipative effects which determine the decaying of the initial transient stages of fluid motion.
A more detailed and motivated-discussion of the present study is reported in the Description of the Research Project.
Training content Two advantages are expected by the applicant from the training period at the DEPARTMENT OF MARINE HYDRODYNAMICS of NTNU (Trondheim-Norway). First, concerning the sloshing problem, a lot of preliminary theoretical and experimental work has been developed by the research group of the Host Institution. Hence, the experience of the applicant in the field of nonlinear free surface flows will be advantageously coupled with this specific knowledge in order to solve the problem at hand.
Second, and more generally, the Host Institution has a tradition in joint theoretical and experimental research activity. It is expected that this period of training will give the applicant a wider vision of such research process. This professional experience will in turn be extremely useful in the context of the applicant's future research activity at I.N.S.E.A.N. Links with industry Though the proposed research is not explicitely linked to industry, the Host Institution holds useful relationship with "Det Norske Veritas" (a classification society), with MARINTEK (a private towing tank) and other shipbuilders. This allows for exchanging professional experiences and experimental data which are extremely useful in developing theoretical models. Another expected benefit for the applicant is related to this kind of cooperation.