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Prediction of ship’s total resistance of a pusher-barge system has become enormous complexity involving nonlinear-hydrodynamic flows behaviour along their hull forms. Both of empirical and simplified numerical solutions may still lead into inaccurate results due to presence of nonlinear characteristics of the pressure and viscous resistances. The use of a more sophisticated method would obviously necessitate to solve the above problem. This paper presents a Computational Fluid Dynamics (CFD) approach to predict the total ship’s resistance of a pusher-barge system at various barge’s configurations. To achieve such objective, four different configurations of the barge models incorporated with various Froude numbers have been taken into account in the computational simulation. In general, the results revealed that the increase of Froude number (Fr = 0.182 to 0.312) was proportional to the magnitude of RT, RP and RV. Regardless of the various Froude number, the pusher-barge system with a 13BP configuration provides the highest resistance compared to the 12BP and 11BP. In addition, the arrangement of barges in the longitudinal (12BP) and lateral (21BP) configurations produced a significant effect with increases in RT, RP and RV values of 110%, 167.5% and 77.6%, respectively. The possible reason for this is that the increase of the total wetted surface area for 21BP has produced to a proportionally higher amount of the pressure and viscous resistance. Overall study, the numerical results were presented and analysed based on few aspects involved the total resistance and resistance coefficient in terms of pressure and viscous resistance of the pusher-barge system. This analysis provides very valuable information on choosing the most reliable arrangement of pusher-barge system. This analysis provides very valuable information on choosing the most reliable arrangement of pusher-barge system

Floating structures, such as Spar platform, are likely to experience significant motions while operation due to Vortex-induced Motion (VIM). The main features of VIM include aspect ratio and mass r...

For offshore structures, especially jacket supported structure such as fixed platform and offshore wind turbine, the underwater area provides an ideal site for corrosion formation and marine fouling. In this marine environment, the structures are exposed to particularly aggressive corrosion and colonized by marine organisms involving a diversity of species. In this paper, a number of cases are conducted where an existing fixed platform is subjected to uniform corrosion. Furthermore, the platform is also subjected to marine fouling. The platform is assessed to investigate the effects of corrosion and marine fouling on its structural strength by determining the Reserve Strength Ratio (RSR) value. It is found the platform is limited to at least 50 years of service life when subjected to average corrosion. However, the platform is no longer considered as safe after 37 years when subjected to severe corrosion. Moreover, there is an RSR loss of 38% when marine fouling is introduced at the first 5 years which is detrimental to the overall safety of the platform. On the other hand, there is minimum RSR loss of only 5% for most cases when marine fouling is introduced but still detrimental to the overall safety of the platform. The obtained outcomes were documented and will be useful information to conduct condition assessment (or structural health monitoring) of aged fixed jacket structures.

This paper presents a computational fluid dynamics (CFD) study of vortex-induced vibration (VIV) for different aspect ratio (L/D) cylinder. Of particular interest was to measure hydrodynamic forces and numerically investigate the wake behaviour of VIV while varying the aspect ratio. The simulation models represented the actual experimental conditions with idealised free-surface boundary condition to capture the responses from fluid-structure interaction phenomenon. The simulations were performed in the subcritical flow region (7.4×103 < Re < 2×105), corresponding to a range of reduced velocity (Ur) from 2 to 14. The results of the cases studied were discussed and compared with the experimental data to verify the accuracy and validity of the present simulation. The comparisons have shown a similar curved-shape drag coefficient plot, and however underestimated the value of the drag coefficients over the reduced velocity. Additionally, the simulations seemed to capture a higher lift force response compared w...