Evaporation of water/ethanol droplets in an air flow: Experimental study and modelling

•Experiments with evaporating suspended water/ethanol droplets in air flow.•Model considering diffusion of species and recirculation inside droplets.•The effect of supporting thread is considered using an earlier developed model.•Considering the effect of thread is shown to improve the model prediction.•Model predictions are compatible with experimental data. The paper focuses on experimental investigation and modelling of the evaporation of supported ethanol/water droplets in an air flow. The modelling is based on the effective thermal conductivity/effective diffusivity model, using the analytical solutions to the transient heat transfer and species diffusion equations in droplets at each time step. The contribution of the supporting thread is included in the model. Model predictions are shown to be compatible with experimental data. For all mass fractions of ethanol, droplet surface temperatures rapidly decrease initially. This is followed by an increase in this temperature for non-zero mass fractions of ethanol in the mixture. For pure water this temperature remains almost constant after an initial decrease. In all cases, droplet diameters to power 1.5 decrease almost linearly with time. This agrees with model predictions in the limit for large droplet Reynolds numbers.