This paper summarizes some of the typical riser vortex-induced vibration （VIV） problems in subsea oil and gas developments, and presents the corresponding computational fluid dynamics （CFD） time domain simula- tio...This paper summarizes some of the typical riser vortex-induced vibration （VIV） problems in subsea oil and gas developments, and presents the corresponding computational fluid dynamics （CFD） time domain simula- tion results to address these problems. First, the CFD time domain simulation approach was applied to analyze the wake field behind a stationary cylinder and a vibrating cylinder. Then a vertical riser VIV response under uniform current was studied. The VIV response time histories revealed some valuable clues that could lead to explanation of the higher harmonics. After that, a vertical riser VIV response under shear current was investigated. A 3 000 ft （1 ft=-0.304 8 m） water depth top tensioned riser was sized, and its VIV responses under uniform and shear current were studied. Then this paper continues to discuss one catenary flexible riser VIV response during normal lay. Last, the time domain simulation approach was applied to a partially submerged flexible jumper, to study the jumper VIV behavior, and dynamic motion envelopes. It was demonstrated that the time domain simulation ap- proach is able to disclose details of the flow field, vortex shedding pattern, and riser dynamic behavior, and han- dle different tvoes of risers under different Woe of currents.展开更多
Automatic coagulant dosage control with streaming current (SC) technique is introduced in this paper. Aluminum and ferric coagulants are widely used in surface water treatment. The SC response characteristics of P Al...Automatic coagulant dosage control with streaming current (SC) technique is introduced in this paper. Aluminum and ferric coagulants are widely used in surface water treatment. The SC response characteristics of P AlCl 3 aluminum coagulant and P FeCl 3 ferric coagulant were investigated in this work. Bench scale water treatment results were obtained from jar tests including rapid mixing, flocculation and undisturbed sedimentation. Results showed that aluminum coagulant is more sensitive than ferric coagulant to SC response.展开更多
文摘This paper summarizes some of the typical riser vortex-induced vibration （VIV） problems in subsea oil and gas developments, and presents the corresponding computational fluid dynamics （CFD） time domain simula- tion results to address these problems. First, the CFD time domain simulation approach was applied to analyze the wake field behind a stationary cylinder and a vibrating cylinder. Then a vertical riser VIV response under uniform current was studied. The VIV response time histories revealed some valuable clues that could lead to explanation of the higher harmonics. After that, a vertical riser VIV response under shear current was investigated. A 3 000 ft （1 ft=-0.304 8 m） water depth top tensioned riser was sized, and its VIV responses under uniform and shear current were studied. Then this paper continues to discuss one catenary flexible riser VIV response during normal lay. Last, the time domain simulation approach was applied to a partially submerged flexible jumper, to study the jumper VIV behavior, and dynamic motion envelopes. It was demonstrated that the time domain simulation ap- proach is able to disclose details of the flow field, vortex shedding pattern, and riser dynamic behavior, and han- dle different tvoes of risers under different Woe of currents.
文摘Automatic coagulant dosage control with streaming current (SC) technique is introduced in this paper. Aluminum and ferric coagulants are widely used in surface water treatment. The SC response characteristics of P AlCl 3 aluminum coagulant and P FeCl 3 ferric coagulant were investigated in this work. Bench scale water treatment results were obtained from jar tests including rapid mixing, flocculation and undisturbed sedimentation. Results showed that aluminum coagulant is more sensitive than ferric coagulant to SC response.
