下游柔性立管的尾流致振频域预报方法

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中图分类号：P756.2 文献标志码：A DOI：10.16385/j.cnki.issn.1004-4523.202306041

Frequency-domain prediction method for wake-induced vibrations ofadownstream flexibleriser

ZHAO Bing，FU Shixiao， ZHANG Mengmeng，DENG Pengqian，FU Xuepeng （Stake Key Laboratory ofOcean Engineering，Shanghai Jiao Tong University，Shanghai 2Oo24O，China）

Abstract：Theriserbundlesystemisanimportantequipmenttoexploreoilandgasinoceanenginering.Underoceanflows，up streamanddownstreamrisers intandemwill experiencevortex-inducedvibrationsandwake-inducedvibrations，respectively， which seriouslythreatens thestructuralfatiguelife.Topredictthevibrationresponsesofadownstreamflexibleriser，this paperde velopsasemiempiricalfrequency-domainpredictionmethodforwake-inducedvibrationsbasedontheclassicalvortex-idcedvibrationpredictionmethodofasingleflexibleriser.Consideringthewakeshieldingefectonthedownstreamriserduetotheexistenceoftheupstreamriser，thereductivewakevelocitybecomes theflowvelocitytoexcitethevibrationsofthedownstreamriser. Then，teupstream-to-downstreamdiameterratioisutilizedtodeterminewhetherthefrequencycaptureocurs.Theaddedmass coeficientoftedownstreamrserwillbeadjustedwhenthefrequencycaptureocurs，otherwiseitislconstantly.Subsequently， thepredictionisbasedonteresonancecondiionTeexcitationcoeficntsfromaseriesofedoscilltiontestsofigidylin derareapproximate tobethewake-inducedfocecoeficients.Acordingtothebalancebetweenthemodalstructuraldamping force andthemodalhydrodynamicforceamplitudes，themodalamplitudecanbenon-iterativelysolved.Afterwards，thewakeiduced vibrationdisplacementscanbecalculatedbasedonthemodesuperpositionmethod.Bycomparingpredictionresults withtheexperimentalresults，the proposed methodcanbasicallcorrectlypredictthedominant frequency，displacement，strainandfatiguedamageof thewake-inducedvibrationforthedownstreamflexibleriser.Therefore，thepresentmethodisconducivetothe multiple-riser system design in practical engineering.

Keywords：wake-induced vibration;frequency-domain prediction；downstream riser;vortex-induced vibration

在海洋工程中，立管系统通常采用集束方式进行安装。（剩余12323字）