Evaporative wicking in thin porous media

Evaporation cooling as an environment-friendly and energy-saving cooling option is usually realized by using porous medium to enhance the transport process, where the evaporation and wicking emerge simultaneously. Thin porous media are commonly applied in the evaporative wicking process. However, the evaporation on thin porous medium imposes significant impact on flow and heat transfer performance of evaporative wicking, which makes the prediction of evaporative wicking behavior more difficult. In this work, experimental studies of evaporative wicking of ethanol in Dutch Twill Weave (DTW) screens are carried out, where the evolution of wicking front and temperature distribution are captured by infrared thermography. Moreover, the numerical model that describes capillary rise, evaporation and heat transfer during evaporative wicking is built, which agrees well with the experimental results. Further investigation suggests that considering the evaporative cooling effect is indispensable for accurately predicting the evaporative wicking behavior in DTW screens. In addition, it is found that there is a rapid increase in temperature difference between the liquid and metal wires around the wicking front based on the local non-thermal equilibrium model.