ISSN Online: 2688-7231
ISBN Online: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
Experimental study of high temperature droplet evaporation on heated surface using IR visualization technique
Phase change heat transfer plays a vital role in improvising the performance of equipment used for high heat flux application. This is because of the proper utilization of sensible and latent heat. Droplet impingement is one of the primitive techniques used for equipment cooling. Evaporation of water droplet from a heated surface involves both heat and mass transfer to the surrounding unsaturated air. This research primarily put light into non-intrusive temperature detection technique to analyze evaporation rate. The experiment is performed using aluminum and copper block. The blocks are maintained at temperature varying from 145°C to 105°C with an interval of 5°C. The surface temperature is measured by implementing non-intrusive measurement technique using Testo 860 IR camera. The surface morphology is performed by analyzing the substrates under optical microscope with a resolution of 20X. The surface roughness is analyzed under profilometer and the rms value for aluminum and copper is found to be 0.2705µm and 0.9697µm respectively. The water maintained at different temperatures (30°C, 50°C, 75°C, 99.4°C) are impinged at volume 100µl on individual substrate at room temperature and the contact angle is measured using contact angle meter and surface tension variation is analyzed. It has been observed that the contact angle and surface tension reduce with increment in liquid temperature. The result shows good agreement for all the studies. It has been observed that the evaporation rate increases with increase in fluid temperature. Higher the surface temperature, higher the evaporation rate. It can be inferred from the results that the magnitude of evaporation rate is higher for copper substrate than aluminum at any given surface temperature and fluid temperature.