Underwater stand pipe vortex induced vibration inhibiter adopting rotatable cowling

Abstract

The invention discloses an underwater stand pipe vortex induced vibration inhibiter adopting a rotatable cowling, belonging to the technical field of ocean stand pipe facility laying. In the invention, the rotatable cowling capable of changing own direction along with the current flow direction is installed on an underwater stand pipe and comprises a pair of rotating modules, a cowling fixing pad and a cowling. The inhibiter is characterized in that the front part of the cowling is round, the rear part of the cowling is pointed, the surface of the cowling is smooth, and the shape of the cowling is similar to a water drop. The circular arc part of the cowling is coaxial to the stand pipe and is connected with a main pipe by the rotating module which is convenient to install and disassemble to cause the circular arc part to freely rotate around the stand pipe. A small-density buoyant material is added in the hollow part of the cowling, and the structural deformation and pivoting friction resistance brought by the asymmetric gravity of the cowling can be eliminated. Because of effectively inhibiting vortex induced vibration, the underwater stand pipe vortex induced vibration inhibiter can improve the fatigue resistance of the underwater stand pipe, thus greatly lowering the engineering cost. Meanwhile, the inhibiter overcomes limitation on incoming flow directions by various vortex induced vibration inhibiters, and has high application value in the environments with frequently changed flow directions of oceans, rivers and the like.

Description

technical field [0001] The invention relates to a vortex-induced vibration suppression device for an underwater riser, in particular to a vortex-induced vibration suppression device for an underwater riser using a rotatable fairing, and belongs to the technical field of marine riser facilities laying. Background technique [0002] The increasing shortage of oil supply has made deep sea oil and gas exploitation highly valued by countries all over the world. There are many slender and cylindrical structures in the deep sea production system, such as drilling risers, oil production risers and suspension transfusion pipelines, etc., and their total cost exceeds 50% of the entire deep sea production system. When waves and ocean currents flow through these pipelines, at a certain flow rate, the wake of the pipeline will produce periodic vortex shedding. When the natural frequency of the pipeline is close to the frequency of vortex shedding, vortex induced resonance occurs, which l...

AI Technical Summary

Problems solved by technology

Therefore, the application of fixed fairings has great limitations for operating environments where the direction of water flow often changes, such as oceans and rivers.

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