Measurement of instantaneous heat transfer using a hot-foil infrared technique

摘要

Hot-foil infrared thermography was employed to measure instantaneous local heat transfer coefficients of falling wavy films. The film flows down an electrically heated thin metal foil which provides a defined heat flux. The heat transfer coefficient of the film flow is evaluated from the temperature on the backside of the foil measured by an infrared camera. Good agreement of the instantaneous measurements with own numerical calculations points out the remarkable sensitivity and time resolution of the technique. The accuracy of the results is confirmed by comparison with recently published time averaged data.