Session: FSI-03-01 Structures Under Extreme Loading Conditions-1

Paper Number: 152731

152731 - Fluid-Structure Interaction Modelling to Predict Rupture of Dense-Phase Co2 Pipelines 

Abstract: 

Fracture resistance in a rupturing pipeline is influenced by the pressure exerted on the flaps of the pipeline by the decompressing fluid. Current engineering methodologies mainly treat the fracture resistance curve and the gas decompression curve as uncoupled. To capture the coupled interaction, the Fluid Structure Interaction technique known as the Coupled Eulerian Lagrangian (CEL) method in Abaqus was used to model pipeline rupture. Initially, the CO₂ fluid is in the dense-phase (supercritical) state but can exist in both a liquid and gas (2-phase) state during decompression. The Equation of State (EOS) for a CO₂–N₂ mixture was calculated using the GERG-2008 EOS in REFPROP. The resultant properties were then used to describe a tabulated EOS in Abaqus for the Eulerian (fluid) domain. A user defined EOS by means of direct equations or a table lookup process were also used for a more accurate description of the EOS of CO₂ mixtures. Isentropic conditions were assumed. The fracture response of the pipeline in the Lagrangian (structure) domain was described using the Crack Tip Opening Angle (CTOA) criterion either directly via a user subroutine or indirectly by informing parameters of damage mechanics models in which the effective plastic strain to failure depends upon stress triaxiality and Lode angle. Full-scale shock tube simulations in the Eulerian domain were performed to validate the EOS by comparison with experimental data. The shock tube simulations were able to capture the 2-phase pressure plateau commonly reported with CO₂ decompression. CEL simulations of a pipeline buried in soil were compared to full-scale CO₂ pipeline rupture data available in literature. The predictions agreed well with the experimental data, with a predicted crack velocity of about 100 m/s. The pressure profile predicted for CO₂ will be discussed and compared to the traditional profiles from natural gas pipeline rupture. The influence of shock waves will be addressed, as well as comparing CTOA versus fracture speed.  

Presenting Author: Bruce Williams CanmetMATERIALS, Natural Resources Canada

Presenting Author Biography: Dr. Williams is a Research Scientist at CanmetMATERIALS studying deformation and fracture of metal in the pipeline, nuclear, and automotive sectors. His research is about 50% computational and 50% experimental. Recently, he has been studying CO2 pipeline rupture using Fluid-Structure Interaction (FSI) codes that employ Eulerian-Lagrangian schemes within Finite Element Analysis (FEA) software.

Authors:

Bruce W. Williams CanmetMATERIALS, Natural Resources Canada
Ifaz Haider CanmetMATERIALS, Natural Resources Canada
Dean Difiore College of Engineering and Physical Sciences, School of Engineering, University of Guelph
C. Hari M. Simha College of Engineering and Physical Sciences, School of Engineering, University of Guelph
Su Xu CanmetMATERIALS, Natural Resources Canada