Optimized design of floating production storage and offloading (FPSO) unit, which resulted in reduction of liquid carry-over in the gas outlet from 7% to 0.0003% during a 10-year storm


During storms, a large amount of liquid carry-over occurred within a two-phase separator. Apollo engineers relied on their experience working with separators and internal components to devise potential solutions. The aim was to reduce the liquid carry-over and ensure that new internals could be fitted to the existing vessel, while withstanding extreme environmental forces.


The geometry was set up with ANSYS DesignModeler using the parameter utility within Workbench. The mesh was constructed initially with ICEM CFD and meshing tools using the interactive option in multi-zone. Once the ICEM blocking script and worksheet flow were written, each mesh was generated within minutes, rather than hours, after each geometry iteration. ANSYS Fluent simulated the effect of vessel motion while onboard an FPSO. CFD-Post determined the forces on baffles and liquid carry-over through the gas outlet. The resulting solution resulted in a near-zero liquid carry-over during a 10-year storm.

Business Benefit:

Automating the meshing process significantly reduced the number of engineer hours spent on each modification. This allowed more iterations to be carried out in leading to a better solution for the client.

Software used:

  • ANSYS CFD-Post
  • ANSYS DesignModeler
  • ANSYS Fluent
  • ANSYS Meshing
  • ANSYS Workbench