Investigation of post-CHF heat transfer for water-cooled reactor application and development of two-phase flow instrumentation

A two-phase loop has been modified to obtain post-CHF heat transfer data with water at system pressures up to 100 psia. Development of a probe to measure non-equilibrium vapor superheat is in progress. A suitable test section for obtaining post-CHF data which will incorporate measurement of vapor superheat is in the design stage. A concept for measuring liquid film thickness in two phase flow has been developed and tested with reasonable success. Optimization of probe geometry is in progress. A suitable method for measuring film velocities is being sought. Present investigation is directed towards the use of hydrogen bubbles as tracers