Analysis of the correction factors and coupling characteristics of multi-droplet evaporation

Abstract

During the multi-droplet evaporation, the droplet interactions slow down the droplet evaporation. Historically, the evaporation processes have been studied mainly based on modifying the isolated droplet evaporation model. The actual multi-droplet evaporation can influence the three-dimensional flow field. However, it is not easy to replace the evaporation progress with the simplified model of the isolated droplet. Due to the complexity of the heat and mass transfer mechanism of the multi-droplet evaporation, the microscopic and accurate experiments are challenging to carry out, which leads to that the existing models are primarily derived from the theoretical aspects. In the present paper, the multi-droplet evaporation systems are simplified as different droplet arrays and reproduced based on the point source method (PSM) by introducing a correction factor to evaluate the inter-droplet interaction. The correction factor is numerically obtained, compared and validated. The parameter sensitivity of the correction factor is conducted systematically. In addition, the influence threshold is introduced to consider the droplet-gas coupling interactions. Thus, the local effects due to the transient evaporation of droplets are corrected. The results reveal that there exists a critical spacing used to determine whether the droplet interactions can be neglected. Additionally, droplets with larger sizes and smaller spacing dominate the inhibitory effect on the studied droplet. Finally, the correction for local effects will significantly reduce the droplet transient evaporation calculation error.