A UNITARY HETEROGENEOUS NUCLEATION MODEL FOR SUPERHEATED COMPRESSIBLE FLOW

摘要

The heterogeneous condensation in the superheated compressible flow is researched numerically by means of developing a unitary heterogeneous nucleation model and a chemical droplet growth model. The former model describes the heterogeneous nucleation occurring on soluble nuclei in a multicomponent system with a low concentration of chemical substances. It links the interfacial surface tension, the size of nuclei and the chemical characteristic of the impurities with the nucleation generation rate. The radius and salt solution dependence on the surface tension of the chemical droplets are also discussed in the paper. Combining the unitary heterogeneous condensation model and the dispersed two-phase flow field calculation method, the heterogeneous condensation in a Laval nozzle is investigated numerically. The flow field distribution of the two phases are obtained and compared with the exerimental results.