Heat and mass transfer of ethanol and methanol droplets with temperature and air flow rates variations

Heat and mass transfer of liquid fuel droplets is important in predicting phenomena in spray combustion and drying. Ranz-Marshall analogy model is one of the most common analogy models used to calculate heat and mass transfer of a substance. In the calculation of heat and mass transfer of substances with Lewis number more than one still shows considerable deviations between stagnant film modification model and Ranz-Marshall analogy model. This study aims to analyze heat and mass transfer in evaporation of ethanol and methanol droplets, and to see the conformity of Ranz-Marshall analogy model by reviewing Re^1/2Pr^1/3 value to Nusselt number on heat transfer calculation and reviewing Re^1/2Sc^1/3 value to Sherwood number on mass transfer calculation. This study uses a test system that drains hot air around droplets that hung in the thermocouple with variations in speed and temperature of the air flowing around droplets. The results showed that Lewis number of the compound tested was more than one and there was considerable deviation between the test results and the simulation results of the Ranz-Marshall analogy model for each tested compound, where Re^1/2 value was less suitable for calculation with different air velocity values and new equations are needed accordingly.