Analysis on the signal features of pressure for gas-water two-phase slug flow in S-shaped riser system

An experiment is carried out in S-shaped riser system for gas-water two-phase flow in this paper. The key signal feature of the pressure at riser base including the change rate, amplitude spectrum and distribution of the pressure at riser base is analyzed to study the main characteristic of the flow. Some interesting results are obtained as follows. As the flow pattern changes from severe slugging to steady state, the change rate of the pressure at riser base becomes more frequently but not abruptly. The main frequency of the pressure wave is becoming larger but the periodicity is weakened. The wave mode of the pressure is more complicated when flow pattern changes. The peak on the pressure distribution graph moves from high value to low value region, and the fluctuation range is reducing while the peak value is also reducing.