Mid wave infrared thermography of water films in condensing and evaporating environments

Measurements were performed in the LINX facility at the Paul Scherrer Institute (PSI). Liquid films were created on a temperature controlled wall placed vertically inside a pressure vessel with controls on thermal-hydraulic conditions. Films were produced either by condensation or via a film injector. The results obtained for selected tests are presented which involve condensation and evaporation on a wavy films with steady state conditions. Measurements with the surface partially wetted by an evaporating rivulet as well as drop wise condensation are reported. Confirmation could be brought that the perturbations caused by the presence of waves on the film impact locally the surface temperature of the film. The convolution and synchronization of mid-wave and near infrared imaging represent a strong analytical tool for the study of two phase flows involving liquid films subject to heat and mass transfers.