Skip to main content

EXPERIMENTAL AND NUMERICAL ANALYSIS OF SLOSHING AND IMPACT LOADS

Objective

The main objective of this project is to develop a fully integrated software for the numerical modelling of the fluid/structure interaction, in terms of free surface motions and impact loads, validated through ad-hoc experiments and applied into innovative design guidelines and procedures.
The EUROSLOSH project has produced significant scientific results, among which the most outstanding are:

- an extensive analysis of the effects of different physical parameters on the sloshing phenomenon: these results, are of particular value as they refer to tanks of simple geometry and are therefore not polluted by side effects which make interpretation questionable; besides this, the experimental activity carried out within the project is believed to have produced one of the most massive, complete and coherent set of model tests on sloshing performed so far;
- an investigation into scale effects: the investigation can be considered as an important starting point for a future research into the scale effects in the sloshing phenomenon;
- a deep analysis of the fluid-structure interaction problem: the "implicit" algorithm developed has a major advantage in being very simple and therefore particularly suited to cope with the VOF method;
- a significant progress in CFD applied to sloshing: several different algorithms and numerical techniques have been implemented and related pros and drawbacks tested on the field, resulting in a considerable experience and step forward.

From a technological point of view, the consortium has significantly progressed in terms of:

- experimental techniques: a big effort was made, mainly by SIREHNA with the assistance of BV, resulting in a considerable increase in the know-how on the equipment and on the techniques to be adopted in sloshing model testing; with particular emphasis was put on impact pressure and peak detection, for which ad-hoc high speed acquisition systems were developed;
- understanding of the effects of sloshing on structures: by means of the evaluation of the structural response to sloshing impact as well as of dynamic pressure loads;
- analysis of relevance of sloshing in different industrial areas: by means of the development of an experimental data base covering four different industrial areas (road transportation, civil engineering, ship and aeronautics); for each area, selected relevant configurations of particularly complex shape were tested.

Finally, a considerable pre-normative nature is to be ascribed to the Project, as shown by the presence of two classification societies within the consortium. In this respect, the most important results comprise:

- a clear understanding of the capabilities and limitations in sloshing simulation by either model tests or CFD techniques;
- a clear understanding of the role of impulsive and of dynamic pressure on ship structures;
- a comprehensive set of experimental results, in particular on double hull ships which enables to assess this new concept of tanker with respect to sloshing loads;
- the development of guidelines for sloshing simulation, comprehensive of a procedure for the analysis of sloshing pressure time-histories (resulting form either model tests or numerical simulations) suited to certification purposes.
The following types of problems will be considered :

-for the shipbuilding industry-large amplitude imposed motions, harmonic or irregular (stochastic), large prismatic (steel) tanks with internal baffles and antiwash bulkheads, or quasi-spherical tanks
-for the automotive industry-tanks for automobiles and road transport
-for the aerospace-tanks in low gravity environment low amplitude excitations, liquid fuel free surface reorientations, surface tension
-for the civil engineering industry-large tanks for liquid storage, stochastic earthquake excitations, concrete (rigid) and (flexible) steel walls.

For the specific problems under examination, the values of free surface orientations and impact loads depend on the modelling of a number of fluid and structural parameters (such as viscosity, compressibility, gas cushioning, structural flexibility, gravity, etc.), which will be properly specified.

Coordinator

REGISTRO ITALIANO NAVALE
Address
Via Corsica, 12
16128 Genova
Italy

Participants (4)

British Aerospace plc
United Kingdom
Address
Sowerby Research Centre Filton
BS12 7QW Bristol
Bureau Veritas
France
Address
6 Rue Henri Saint Claire Deville
92563 Rueil-malmaison
Centro per gli Studi di Tecnica Navale SpA (CETENA)
Italy
Address
Via Al Molo Giano
16126 Calata Grazie Genova
Société d'Ingénierie, de Recherches et d'Études en Hydrodynamique Navale
France
Address
2 Quai De La Jonelière
44300 Nantes