Fast numerical simulation for full bore rupture of pressurized pipelines

Decompression wave speed in CO2 mixtures: CFD modelling with the GERG-2008 equation of state

“…The MOC solves the fluid flow conservation equations by following the Mach-line characteristics inside the pipe. It is claimed that numerical diffusion related to the finite difference approximation of partial derivatives is reduced by this method [33,34], but the MOC needs much longer computation runtimes and cannot predict non-equilibrium or heterogeneous flows [25,35], while the FVM is better at dealing with multi-dimensional flow. In the existing CFD models, the cubic Peng-Robinson (PR) EOS [36] is often used due to its relatively simple mathematical form compared to other more complex (but more accurate) EOS such as AGA-8 [37], BWRS [13] and GERG [20].…”

An integrated, multi-scale modelling approach for the simulation of multiphase dispersion from accidental CO2 pipeline releases in realistic terrain

“…The process of sublimation was simulated using the standard evaporation model, with suitable Antoine equation coefficients for solid CO 2 sublimation. Drag between the CO 2 Schiller and Naumann (1933 particles and the surrounding gas phase was calculated using the drag model of ) combined with the stochastic dispersion model of Gosman and Ioannides (1981) to account for turbulence effects. Heat transfer between the gaseous and solid phases was modelled using the RanzMarshall correlation (Ranz and Marshall, 1952) and turbulence effects in the gas phase were modelled using the Shear-Stress Transport (SST) model of Menter (1994).…”

“…In the current study, two-phase CO 2 Ichard, 2012 dispersion phenomena in FLACS (GexCon AS, 2013) are modelled using an Euler-Lagrangian method ( ). The numerical particles are modelled as point-particles (Loth, 2000), with the particles considered incompressible, nonreacting, and spherical in shape.…”

“…It involves the capture of CO 2 and its storage in suitable semi-permanent reservoirs such as naturally formed saline aquifers or depleted oil wells, instead of allowing its release to the atmosphere where it contributes to climate change. In most of the planned CCS projects, the CO 2 is transported from the capture to the storage sites in high-pressure pipelines, typically operating at pressures above 80 bar, where the CO 2 Whilst the physics of high-pressure releases of substances such as natural gas and propane is relatively well understood ( is in either a supercritical or liquid state, depending upon whether it is above or below the critical temperature of 304.19 K. Cowley and Tam, 1988;Richardson and Saville, 1996), CO 2 possesses some unusual physical properties which make its release behaviour more challenging to predict. As pure CO 2 , its triple-point pressure and temperature are 5.18 bar and 216.55 K respectively, and at atmospheric pressure CO 2 is a colourless and odourless gas under ambient conditions, and is toxic if inhaled in air at concentrations around 5%, and likely to be fatal at concentrations of around 10% ( ).…”

“…In assessing the hazards posed by releases of CO 2 , it is important to take account of the fact that the CO 2 gas will be much denser than air, due to both its higher molecular weight and very low temperature. This could lead to a gravity-driven flow of high CO 2 The modelling of outflow and subsequent atmospheric dispersion following pipeline failure is especially challenging given the large number of complex and often interacting processes governing the phenomena involved. The rupture of the pipeline results in a series of expansion waves that propagate into the undisturbed fluid in the pipe towards the intact end of the pipeline.…”