VERY DEEP FACILITIES PHYSICAL MODELLING STRATEGIES

Abstract

The design process for offshore facilities has used a mix of physical and numerical modelling to provide information on loads and steady dynamic responses in an efficient and accurate fashion. Usually physical modelling is used early in the design process to provide force coefficients for novel forms or novel loading conditions. Physical modelling is also used later in the design process to deal with complex issues for which the available numerical models are not adequate or are inefficient, and it is subsequently used to provide a verification of the final design under a comprehensive set of load cases.

All of these applications of physical models remain important in the move to very deep water, but the limitations of water depth, plan area and velocity profile in existing laboratory facilities reduce the capability of physical modelling. At the same time the wide range of novel hull forms, mooring configurations and materials, and riser types increases the requirement for physical data to calibrate the numerical models and increases the need for design validation. Physical modelling procedures, facilities and limitations are discussed and a design methodology is outlined.