Statistical rate theory development for evaporation on ice droplets

• Main Author: Wong, Choon Hong.
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/53435
• Institution: Nanyang Technological University

Evaporation is a process of changing a substance from liquid phase to vapor phase. It occurs in many of the engineering applications. Thereby, there is a need to understand the evaporation process thoroughly so that the process can be more predictable and controllable. Hence, there is a theoretical approach was deducted from transition probability concept of quantum mechanics and Boltzmann deification of entropy. The theoretical approach is evaporation Statistical rate theory (SRT) which is a developed theory to predict the rate of evaporation and saturated vapor phase pressure under different conditions and substances like water and ethanol. Saturated vapor phase pressure is one of the parameter in the evaporation flux equation and statistical rate theory (SRT) equation. Thereby, saturated vapor phase pressure can be deducted by obtaining all the necessary parameter in the statistical rate theory (SRT) namely temperature jump between the interface of liquid and vapor, vapor phase temperature, radius of ice droplet and evaporation flux of ice droplet in the control condition during steady- state evaporation. The saturated vapor pressure values were converted to into voltage values with the calibrated pressure equation, V = 71237X - 17284. Then, voltage values of saturated vapor phase pressure from statistical rate theory (SRT) equation were compared with the voltage values of local vapor pressure obtained from independent measurements. The voltage values of saturated vapor phase pressure from statistical rate theory (SRT) equation are in the range of 0.247V to 0.248V whereas voltage values of local vapor pressure obtained from independent measurements are in the range of 0.242V to 0.248V. The voltage values of saturated vapor phase pressure from statistical rate theory (SRT) equation shown that voltage values of saturated vapor phase pressure values obtained from statistical rate theory (SRT) equation were highly consistent with the measured voltage values of local vapor pressure obtained from independent measurements. Thought out the experiment, the root mean square distortions from the two pressures are about 2 %. In the future work, people can make use of statistical rate theory (SRT) equation with organic substance to do future research.