ICONE15-10542 APPLICATION OF INTERFACE TRACKING METHOD TO INVESTIGATE SOME PHENOMENA INVOLVED IN FUEL-COOLANT INTERACTIONS

抄録

In the course of a severe reactor accident, molten core will drop into water as a coherent jet and the jet will be broken into droplets. Both the melt jet and droplets are surrounded with a vapor film because of high temperature of the melt. The existence of this vapor film could affect both the jet breakup behavior and movement characteristics of a melt droplet. The work of this paper is to perform numerical simulation of interfacial phenomena to investigate the micro-physics of these multiphase interactions. A computer code using Volume-of-Fluid (VOF) method to track interface is established for this purpose. Some special strategy is used to deal with the rapid vaporization on the liquid-vapor interface. Simulation of film boiling around a hot static sphere in a flowing field using body fitted coordinate is performed in order to give some insight into the premixing phase of a steam explosion. The drag force exerted on the sphere with vapor film in the whole course is analyzed. The code is extended to treat with three fluid representing melt, vapor and volatile liquid to simulate high temperature jet entering to volatile liquid. The leading edge behavior due to boundary layer stripping is described by the code.