The Effect of Liquid Mass Flow Rate on Heat Transfer for an Air-Water Atomizing Mist Jet
This paper presents experimental work on the heat transfer characteristics of an impinging water-air atomizing mist jet. Both time averaged and fluctuating heat transfer coefficient profiles are presented for varying liquid flow rates, air Reynolds numbers and nozzle-to-plate distances. Even for very low liquid flow rates, substantial heat transfer enhancement was observed. For the lowest liquid flow rates, increasing the Reynolds number did not give rise to an increase in stagnation heat transfer, as is the case for air jets at the same nozzle-toplate distance. A logarithmic relationship was found to exist between the water-to-air flow rate ratios and the stagnation heat transfer values. The fluctuating heat transfer behaviour was seen to vary with liquid flow rate. At the lowest flow rates the fluctuations were at a maximum in the stagnation region of the jet, whereas at higher liquid flow rates a minimum in fluctuations was observed in the stagnation region.