Theoretical studies of density wave instability with low pressure and low quality and its application in low temperature nuclear heating reactors

It was found that the research of two-phase flow instability with natural circulation was of importance to nuclear reactors and other heat transfer equipment. This paper is to summarize the theoretical studies on density wave instability with low pressure and low quality and natural circulation. It describes analytical methods for analysing two-phase flow density wave instability and the development of draft flux models and nonlinear problems. The estimation of linear stability boundary and effects of parameters on it in the two-phase flow with natural circulation are given. The results of non-linear density wave oscillation and dynamical instability are shown. it also explores the possibility to induce general excess entropy production criterion in two-phase flow, which was developed in non-equilibrium thermodynamics, to establish an energy principle of density wave instability. The spectral entropy features that can reveal the physical mechanism of two-phase flow instability are also discussed. Finally, the application of obtained results to the safety design in the low temperature nuclear heating reactors is presented