Surrogate FMU: Pipeline Junction with Simcenter Flomaster

Oil transportation from shore-based storage facilities to ships anchored offshore is often analysed using 1D simulation tools such as Simcenter Flomaster. In this tutorial, the flow behavior through a 3D component is characterized using Simcenter STAR-CCM+, exported as an FMU, and introduced within a 1D model of a ship to shore system in Simcenter Flomaster.

In oil transportation networks, the tankers and vessels that carry the oil often dock with an offshore buoy known as a Single Point Mooring (SPM). SPMs are structures anchored to the sea floor at which vessels can dock in order to remain stationery while loading or unloading oil. Oil is transported between the SPM buoy and the shore through a pipeline that ends in the onshore terminal. The onshore terminal typically contains the tank farm and a pumping system that drives the flow.

When designing ship to shore networks, engineers often want to explore the effect of different scenarios on the overall system behavior. In steady state analyses, for example, engineers are interested in knowing whether pipe sizes are correctly matched to the mass flowrates generated by the pumping system. Transient analyses often look at failure scenarios such as those caused by sudden disconnection of a tanker from the oil pipeline.

Whenever a flow network contains a component whose flow behavior cannot be adequately characterized by analytical methods, an alternative source of data is required. A common approach is to introduce a Functional Mockup Unit (FMU) that provides realistic responses to the inputs supplied by the flow network. In order to generate the FMU, another source of component characterization is required such as high-fidelity 3D simulations. The results of these high-fidelity simulations can be captured using response surface (surrogate) methods.

In this tutorial, a steady state analysis is presented where the flow through a bespoke component (4-armed junction) is characterized by means of 3D simulation in Simcenter STAR-CCM+ and then imported into Simcenter Flomaster as an FMU. The FMU is generated using the surrogate computation facility within Design Manager, which is part of Simcenter STAR-CCM+. The coupling between the 1D system and the 3D surrogate is illustrated as follows:

The extension of the model to perform transient simulations to evaluate the impact of dynamic events like for example water hammer events is presented in a dedicated tutorial (Sample System) available in Simcenter Flomaster.