An experimental study on heat transfer mechanisms in the microlayer using integrated total reflection, laser interferometry and infrared thermometry technique

On a visible-transparent boiling surface, the detailed geometry of a microlayer can be detected using a total reflection technique combined with laser interferometry. On an infrared-opaque boiling surface, the surface temperature and heat flux distribution can be obtained using a high-speed infrared thermometry technique. In the present study, an experimental technique to study heat transfer in the microlayer is described that permits the simultaneous use of the total reflection combined with laser interferometry and infrared thermometry. Boiling takes place from an infrared-opaque and visible-transparent indium-tin-oxide thin-film heater deposited on an infrared- and visible-transparent calcium fluoride substrate. Details of microlayer geometry and the associated surface temperature and heat flux distribution are obtained using an integrated experimental technique. Heat transfer mechanisms in the microlayer are quantitatively discussed.