High-order discontinuous Galerkin computation of axisymmetric transonic flows in safety relief valves

This paper presents a discontinuous Galerkin (DG) discretization of the compressible RANS and k- ω turbulence model equations for two-dimensional axisymmetric flows. The developed code has been applied to investigate the transonic flow in safety relief valves.This new DG implementation has evolved from the DG method presented in [1]. An "exact" Riemann solver is used to compute the interface numerical inviscid flux while the viscous flux discterization relies on the BRMPS scheme [2,3]. Control of oscillations of high-order solutions around shocks is obtained by means of a shock-capturing technique developed and assessed within the EU ADIGMA project [4].The code has been applied to compute the flow in a spring loaded safety valve at several back pressures and different disk lifts. The predicted device flow capacity and the pressure inside its bonnet have been checked against experimental data. The CFD simulations allow to clarify the complex flow patterns occurring and to explain the measured trends.