Internal Flow Analysis of FPU Oil Separator Considering Six Degrees-of-Freedom Ship Movement

摘要

A practical sloshing analysis for a top side equipment of a FPU(Floating Production Unit) is presented considering six degreesof freedom of motion for the FPU. Since a FPU has variouskinds of oil separator, it is important to stabilize the free surfacelevel of the fluid filled in the oil separator tank in order toproduce of crude oil without interruption. In the present work,the effect of the floating body motion on the free surface in thetank is investigated. The motion of FPU is calculated accordingto the three dimensional panel method. The motion response inthe frequency domain is converted to the time domain by inverseFourier transform. The six-DOF motion of the FPU is used as atime variant boundary condition in the CFD analysis. Theinternal flow is assumed as laminar for the sake of the concisecomputation. The VOF model with geometrical reconstruction isapplied for simulating the free surface in the tank. The first orderof upwinding and time marching scheme are used. To evaluatethe free surface level in the tank, the distance between the tankbottom and the free surface in a specified position is picked up.From the analysis, it is concluded that the effect of the floatingbody motion could be negligible in a sloshing point of viewunder the given ocean environmental condition.