Experimental investigation on pressure fluctuation of cryogenic liquid transport in pitching motion

The floating production, storage and offloading units for liquefied natural gas (LNG-FPSO) have gained increasing attentions in recent years. The transport process of liquefied natural gas (LNG) between LNG-FPSO and LNG carrier is regarded as one of the technical challenges for the novel unit. In particular, the pressure fluctuation induced by ship motion is one potential risk during the cryogenic liquid transport. In the present paper, experimental simulating platforms, which can pitch in different angles and frequencies, have been designed and constructed. Cryogenic liquids are transported between the pitching platforms. The pressure characteristics of cryogenic liquid transport in pitching motion and the influencing factors have been experimentally investigated. In addition, the fluid flow in the pitching pipe has been theoretically analyzed as well.

► An experimental setup simulating offshore cryogenic liquid transport is designed.
► Large amount of experiments have been done for turbulence flow in pitching motion.
► The period of pressure fluctuation is determined by the pitching frequency.
► The amplitude of pressure fluctuation increases with pitching angle and frequency.