Measurement of diffusion fields of solutions using real-time phase-shift interferometer and rapid heat-transfer control system Original Research Article

A new measurement system for investigation of transient diffusion fields using an accurate interferometer system was developed. This system was composed of a rapid heat-transfer control system and a real-time phase-shift interferometer. The heat-transfer control system had a small test-cell in which the liquid temperature was controlled by non-equilibrium thermoelectric device. In order to investigate pure diffusion fields without double diffusive convection, micorgravity experiments using an airplane were carried out. Thermal and mass diffusion fields of aqueous solutions of NaClO3 and Ba(NO3)2 were measured by the system. Thermal and mass diffusion fields were investigated with various temperature conditions. The effect of double diffusive convection on the measurement of diffusion fields was observed. Mass diffusion of NaClO3 solution in various temperature gradients was measured in normal and micro-gravity conditions. The relation between crystal growth and super cooling was investigated, and no crystal growth was observed at small supersaturation ratio. The result agreed with that obtained using a small rocket experiment.