A CFD computational model for high-pressure liquid CO2 decompression

Abstract

Abstract A CFD decompression model with considering external flow field is established based on the non-equilibrium phase transition. The results of pressure and decompression wave speed calculated by CFD are compared with the results of “shock tube” test, showing good agreement. On this basis, the effects of external flow field on the transient behaviour of liquid CO2 decompression in the pipe is further investigated. It is found that the external flow field basically has no effect on the variation of pressure and decompression wave speed in the pipe. Moreover, a Mach disk is formed at about 7.35R (R is the radius of rupture opening, 19.05 mm) away from the rupture opening in the process of jet expansion. Although the external flow field has a significant influence on the static pressure at the rupture opening, the mass flow in the case without considering external flow field is larger than that with considering external flow field, and the overall difference between the two cases is within 6%.