Thermofluid patterns at liquid surface with non-uniform heating

Abstract

The thermofluid patterns are investigated at pure ethanol surface with non-uniform heating. The purpose of this study is to understand the behaviour of hydrothermal waves while ethanol is placed under an evaporation process in a series of experiments with various parameters. With the implementation of a heating plate to heat the copper substrate with ethanol in it, the evaporation of ethanol are tested on various temperatures (30 ̊ C, 35 ̊ C, 40 ̊ C, 50 ̊ C, 60 ̊ C, 65 ̊ C). Furthermore, the usage of the contact angle measurement table allows the evaporation of ethanol to be tested on ten different angles with a range of 10 ̊ ≤ θ ≤ 60 ̊. With a total of three attempts of the experiment, the experiment results are compared using two different methods: same theta with various temperatures and same temperatures with various theta. It is observed that the wavelength of the hydrothermal waves decreases with an increase in either angle or temperature. As a result, more formation of hydrothermal waves are observed, and the thermofluid patterns become more stable. Further experiments were also carried out with a copper substrate of a different design. Using a temperature of 60 ̊ C, ethanol was placed in the above-mentioned copper substrate. Due to the uneven level of copper substrate, the ethanol was exposed to a different fluid depth and heat transfer rate. Future studies can be related to the different shapes and patterns of the copper substrate.