A new, non-intrusive method is proposed to measure the solid-liquid contact temperature during dropwise evaporative cooling. The droplets are deposited onto a material, BaF2, which is transparent in the infrared spectral band. The transparent tile is coated with a very thin layer of high-emissivity, opaque paint on its upper side, so that it can effectively respond to the infrared camera below. The interface temperature can thus be measured through the solid material by a thermographic camera. Tests are carried out on the black painted BaF2 disk after its optimization by mechanical machining. The experimental tests are conducted following two deposition procedures: a) multi-droplet arrays, b) sprays. The two different behaviors and the corresponding cooling results are finally compared.
Droplets wall interaction: Measurement of the interface temperature through infrared-transparent media / Tartarini, Paolo; Santangelo, Paolo Emilio; Tarozzi, Luca. - (2006). ((Intervento presentato al convegno DITICE Workshop “Drop/wall interaction: Industrial applications, Experiments and Modeling” tenutosi a Bergamo, Italia nel 18-19 maggio 2006.