Development and verification of code for simulation of vapor-liquid two phase 2D pressure wave propagation

Abstract

BackgroundThe propagation of pressure waves in nuclear energy systems will cause hydraulic load effects, and it is particularly important for the analysis of structural loads to accurately simulate the propagation process of pressure waves. System analysis codes such as RELAP5, TRACE, etc. are widely used in the simulation and analysis of reactor pressure wave propagation. But system analysis codes can only simulate one-dimensional pressure wave propagation behavior.PurposeTo cope with the multi-directional and multi-dimensional pressure wave propagation issue, corresponding model and algorithm study is carried out in this paper to investigate the two-dimensional pressure wave propagation behavior in two-phase steam-water flow condition.MethodsBy employing a four-step algorithm of time-step separation, and a non-equilibrium phase transition heat transfer model, a two- dimensional two-phase flow pressure wave propagation code (TPFPWPC-2D) is developed based on 2D axisymmetric cylindrical coordinate system. The code verification is carried out by using a typical benchmark of steam-water two-phase shock tube. Finally, in order to verify the ability of TPFPWPC-2D code to simulate the two-dimensional propagation of pressure waves, numerical simulations of the pressure wave propagation behavior in a cylindrical space region were conducted.ResultsThe results of code verification show that the new code proposed here agrees well with the two system analysis codes RELAP5 and WAHA. The 2D simulation application shows that the new code can capture the 2D propagation processes of pressure wave reasonably, especially the reflection and superposition characteristics.ConclusionsFrom the results mentioned above, conclusions can be drawn that the new code developed in this paper can simulate the two-dimensional axisymmetric propagation characteristics reasonably in both quantitative and qualitative levels.

Keywords

• two-phase flow
• pressure wave propagation
• two phase shock wave tube
• 2d propagation characteristics
• code development