Analysis of Flow Instability Types and Dynamic Behaviors for Supercritical Water

Numerical analysis has been carried out for supercritical flow instability in two parallel chan-nels by applying in-house code SCIA.The dynamic behaviors during flow oscillation have been analyzed.Curves of pressure drop versus flow rate are obtained.Results show that the period of supercritical flow in-stability is 1~2 times of the fluid transit time;the propagation of mass flux perturbations delays between inlet and outlet;and mass flux perturbations propagate faster in pseudo-critical region than other regions.The similarities between supercritical flow dynamic behaviors and the density wave oscillations（DWO） charac-teristics indicate that DWO exits in supercritical region,while the curves of pressure drop versus flow rate show that the Ledinegg instability can hardly occur.