%0 Journal Article %A Francois, Fabrice %A Delhaye, Jean-Marc %A Clement, Philippe %D 2011 %I Begell House %K drift-flux, distribution parameter, forced convective boiling, subcooled boiling, saturated boiling %N 1 %P 77-100 %R 10.1615/MultScienTechn.v23.i1.40 %T THE DISTRIBUTION PARAMETER C0 IN THE DRIFT FLUX MODELING OF FORCED CONVECTIVE BOILING %U https://www.dl.begellhouse.com/journals/5af8c23d50e0a883,1890cf7e25bf629f,2ef0694d29ecd89f.html %V 23 %X Forced convective boiling is of great interest for several applications in the power and process industry, particularly in nuclear plants. Depending on the type of pressurized water reactors, boiling may be encountered in the cooling channels during startup, nominal, incidental or accidental conditions with void fractions as large as 0.90. The objective of the present study is to characterize the two-phase flow patterns under such thermal hydraulic conditions. Using experimental data sets obtained on a Refrigerant 12 (R12) loop at CEA/Grenoble, we have shown that at high void fractions the flow behaves like a bubble emulsion; i.e., the liquid phase remains the continuous phase whatever the void fraction. On the basis of this conclusion, we propose a new model for the distribution parameter, C0, of the drift-flux model. This model is first qualified on subcooled, low void fraction R12 experimental data in a circular tube. The model is then shown to give results in good agreement with high void fraction saturated R12 data in a circular tube as well as with experimental data obtained for water saturated boiling at pressures greater than 10 MPa in narrow rectangular channels. %8 2011-07-26