Effect of parameter in drift-model on two-phase flow analysis

The author investigates the behavior of two-phase flow and flow instability in a 5 MW nuclear heating reactor test loop HRTL-5, which simulates the geometry and system design of the 5 MW reactor. It points out that the chose of distribution parameter C0 and drift velocity Vvj may have significant effect on the result of static and dynamic analysis of the system, when one-dimensional two-phase flow drift model with conservation equations for mass, steam, energy and momentum was used. C0 has no great effect on the steady mass flow rate, usually it can be ignored. In the range of Vvj = 0.0∼0.6 m/s, Vvj has about 6% effect on the steady mass flow rate, but has 53% effect on the void fraction at the exit of the heated section. The result by drift model (C0 = 1.1, Vvj = 0.48) shows 15% difference from that by homogeneous model (C0 = 1.0, Vvj = 0.0) on the predicting of instability boundary. In this analysis C0 = 1.1 and Vvj 0.48 are used. Calculated results of both static and dynamic states by drift model agree with experimental data well under the 5 MW nuclear reactor conditions