Numerical examination on the effect of internal fluid presssure on the hydrodynamic response of a marine riser

Abstract

Marine risers are long slender structures which links the floating vessel on the sea surface and its manifold on the sea bottom. It acts as a transportation means for the hydrocarbon resources underneath the sea bed. A riser mainly undergoes hydrodynamic loading which leads to Vortex induced vibrations (VIV) or Flow induced vibrations. These are motions induced on bodies interacting with an external fluid flow producing periodic irregularities on the flow which leads to fatigue damage of offshore oil exploration and production risers. Therefore, suppressing of VIV by providing helical strakes, fairings etc. is necessary in order to reduce the fatigue damage of risers due to hydrodynamic loading. The present paper deals with the numerical study on the response of a marine riserdue to the effect of internalfluid pressure. The initial work is carried out in ANSYS ICEM CFD software. The CFD solution after analysis is obtained from ANSYS FLUENT. The hydrodynamic effects like lift and drag forces along with motion responses is obtained.