Simulation of two-phase flow through ducts with discontinuous cross-section

Abstract

The development of an AUSM+-up based scheme for simulating transient single or two-phase flows through ducts with discontinuous or abrupt changes in area is presented. The non-conservative terms in the governing equations arising from the variation in the duct area are discretised to maintain exactly states at rest. An additional scaling of the pressure based dissipation is added to ensure numerical stability across the area change. The extensive application of the scheme to ideal gas and two-phase CO 2 based on the Homogeneous Equilibrium Model (HEM) for both shock tube and other transient flow problems indicate the scheme's capability to resolve such problems accurately and robustly.

Shale gas well blowout fire and explosion modelling

“…Furthermore, x g is the local projection of the gravity force on the x axis, w q is the heat flux at the pipe wall, and w f is the Fanning friction factor, calculated using Chen's correlation [12]. The model accounts for variation in the inclination of the well with the depth, and can be easily extended to account for the effects of thermal and mechanical non-equilibrium between the fluid phases during the decompression process [11], as well as the variation in the flow area along the well [13]. Peng-Robinson (PR) [14] Equation of State (EoS) is employed to predict the pertinent fluid properties within the well.…”

Numerical study of the effect of heat transfer on solid phase formation during decompression of CO2 in pipelines

“…In the present study, in order to predict the history of decompression of a CO2 pipeline ( Figure 1) accounting for spatial variations in the flow along the pipe, a set of quasione-dimensional HEM-based mass, momentum and energy conservation equations, is applied [15]:…”

Hybrid fluid–structure interaction modelling of dynamic brittle fracture in steel pipelines transporting CO 2 streams

“…The numerical solution of the set of above mentioned quasi-linear hyperbolic equations describing flow in a variable cross-section are pipe is performed using the Finite-Volume Method as described by LeVeque (2002). Details of the implementation of this method were previously described by Brown et al (2015), and for brevity are not included here.…”

“…In order to predict the state of the fluid in a pipeline during fracture propagation, the one-dimensional flow model is developed based on the decompression model describing oultflow from pipelines with stationary cracks (Mahgerefteh et al, 2006;Brown et al, 2015). This model uses the HEM assumption which implies thermal and dynamic equilibrium between saturated liquid and vapour phases, and accounts for a change in the flow area of the pipe.…”