Modeling of bubble-layer thickness for formulation of one-dimensional interfacial area transport equation in subcooled boiling two-phase flow

Axial development of subcooled boiling flow in an internally heated annulus

“…The drift-flux model developed in our previous study (Hibiki et al 2003b) can reproduce the axial developments of the interfacial velocity very well. The averaged prediction accuracy for all the data listed in Table 1 is estimated to be within ±5.92 %.…”

“…The flow can roughly be characterized as two distinctive flow regions, (i) boiling two-phase (bubble layer) region, and (ii) liquid single-phase region. This indicates that the bubble-layer thickness model can be applicable for formulation of one-dimensional interfacial area transport equation in subcooled boiling two-phase flow (Hibiki et al 2003b). …”

“…Data at lower qualities correspond to axial locations closer to the channel inlet. The solid and broken lines in Fig.3 indicate the spline interpolations of the one-dimensional void fractions calculated by the following drift-flux model (Hibiki et al 2003b).…”

“…It should be noted here that Eq. (4) is applicable only to a boiling flow in an internally heated annulus, since the distribution parameter is affected by the channel geometry (Hibiki et al, 2003b). The void fraction can be calculated from indicates the reference line at x eq.…”

“…In addition to this, some important researches related to the interfacial area transport equation have recently been conducted on (i) separate effect tests using adiabatic air-water flow in an annulus to identify the effect of bubble coalescence and breakup on the interfacial area transport (Hibiki et al 2003a), (ii) modeling of bubble-layer thickness to formulate one-dimensional interfacial area transport equation in subcooled boiling flow (Hibiki et al 2003b), and (iii) modeling of active nucleation site density to identify the boundary condition in subcooled boiling flow (Hibiki and Ishii 2003). In order to develop the reliable interfacial area transport equation, extensive accurate data sets should be collected in various channel geometries, flow regimes, and flow conditions.…”