A 3-D EULERIAN-LAGRANGIAN MODEL OF DISPERSED FLOW FILM BOILING .2. ASSESSMENT USING QUASI-STEADY-STATE DATA AND COMPARISON WITH THE RESULTSOF 1-D ANALYSES

The hybrid Eulerian-Lagrangian model developed in the companion paper (Part I) is assessed against several post-critical-heat-flux data sets , obtained in both reflooding and slowly advancing quench front experi ments using the hot patch technique. The calculated results are genera lly in good agreement with the data; the good prediction of the high v apour superheats is due to the low values of the interfacial heat tran sfer which results from the droplet clustering around the centre of th e channel For comparison with the usual one-dimensional approaches, a one-dimensional mode! is also derived, which uses a single diameter re presenting the droplet population, and its results are compared with t hose obtained by the new three-dimensional model. For conditions of lo w mass flux and not very high void fraction at the quench front, the I -D analyses underpredict the vapour superheat as the calculated interf acial heat transfers are presumedly too high. The limitations of the m odels implemented in the large reactor safely computer codes are also discussed. (C) 1997 Elsevier Science Ltd.