Methodology to calculating the temperature around an evaporating droplet using a set of thermocouples

A new approach is proposed to calculating the gas/vapor temperature field in the immediate vicinity of a droplet using a set of thermocouples. The schemes used in the experiments are based on convective and combined droplet heating. The air temperature during droplet heating was varied in the range of 100-500 degrees C, and the droplet radii from 1 mm to 1.7 mm. The paper describes data processing algorithms and methods for calculating the gas/vapor temperature field around a droplet using three to five series of measurements and shows the advantages of this approach over non-contact optical techniques. We also determine the applicability range of the proposed method for temperature field calculation and the limits of systematic and random measurement error variation. The instantaneous droplet radius and the initial air temperature around it are shown to be the main factors influencing the gas/vapor temperature distributions around an evaporating droplet. The experimental data are compared to earlier research findings. The results indicate that reliable gas/vapor temperature fields around evaporating liquid droplets can be obtained even with inexpensive equipment.