A Methodology for Assessment of Internal Flow-Induced Vibration (FIV) in Subsea Piping Systems

Abstract

A methodology is presented for assessing internal flow-induced vibrations (FIV) in subsea piping systems. Finite Element (FE) models are constructed for the subject piping systems, including insulation, internal hydrocarbon weight and added mass of the surrounding sea water. Operating vibration data are measured using ROV-deployable accelerometer loggers clamped directly to the piping systems. The measured data are processed, analyzed and used for two purposes: model verification and dynamic response correlation. Modal parameters are extracted from the measured data and compared to the modal parameters computed from the structural FE model. The model is refined until the frequencies and mode shape errors are within the desired tolerance. The measured data are then used to derive a representative forcing function for use with frequency-domain random response analysis. The forcing function is derived such that the properties of the predicted vibration spectrum match those of the measured vibration spectrum for all measurement locations. The method presented herein provides a novel semi-empirical technique for calibrating FE models to make fatigue life predictions for subsea piping systems using measured vibration data.

Measuring water flow rate for a fire hose using wired accelerometers for smart fire fighting

“…Studying pipe vibration is important for utility pipelines because over a long period of time the vibrations can result in fatigue loading and eventually lead to pipe failure. Research has been conducted to measure fluid flow in utility pipelines using accelerometers [4][5][6][7][8][9][10]. The study of vibration in flexible pipe like a fire hose has received much less attention.…”

Measuring water flow rate for a fire hose using a wireless sensor network for smart fire fighting

“…18) [23]. The decreasing trend at higher flow rates was not expected based on previous research for rigid pipes [8][9][10][14][15][16]. The peaks also continued to occur in approximately the same region as for the wired tests.…”

“…Vibrations from fluid or gas flow can occur in any relatively rigid pipe such as water, oil, and gas utility or industrial pipes. Wired sensors, including accelerometers, have been attached securely to the outside surface of rigid pipes to measure fluid or gas induced pipe vibrations to determine flow rate within the pipe in research settings as well as in the utility pipeline industry [3][4][5][6][7][8][9][10][11][12][13][14][15][16].…”

“…A detailed literature review was included in the previous technical report [23] describing past work focused on detecting vibration from flowing water in relatively rigid pipe using sensors like accelerometers [24]. Standard deviation of acceleration increased as flow rate increased in rigid pipes [8][9][10][14][15][16]. This relationship was found to be similar for flexible fire hose at lower flow rates, from 0 LPM to at least about 300 LPM (80 GPM), however at higher flow rates, above 300 LPM (80 GPM), the standard deviation of acceleration became unpredictable, often peaking and decreasing [23].…”

The Connection between flow pattern evolution and vibration in 90‐degree pipeline: Bidirectional fluid‐structure interaction

“…In the past, scholars focused on axial flow and lateral flow-induced vibration research for specific industrial problems in various fields, which have far surpassed internal flow-induced vibration. [22][23][24][25] In recent years, more and more attention has been paid to the internal two-phase flow-induced vibration on pipeline components, [26][27][28][29] rotating components such as elbows suddenly change the flow direction, which leads to an increase in the probability of large amplitude vibration. 26,[30][31][32] The main frequency of pipeline vibration is mainly linearly related to the liquid superficial velocity, but is less related to the gas superficial velocity.…”