Heat Transfer under Buoyancy-Induced Flow at the Chemical Reaction Front Using Thermochromic Liquid Crystal Sheet

Heat transfer and hydrodynamics at the chemical reaction front have been investigated experimentally using a thermochromic liquid crystal sheet. If the chemical reaction occurs, a band region where the temperature, due to the heat of reaction, is higher than the initial temperature appears at the reaction front. Natural convection due to the temperature difference at the reaction front plays an important role in conveying the higher temperature fluid. For the hydrochloric acid (HCl)–sodium hydroxide (NaOH) system, as the frequency of contact between HCl and NaOH due to convection increases with the concentration of ethanol, the temperature beyond the stagnation point becomes higher than that in other areas. On the other hand, for the acetic acid (CH3COOH)–NaOH system, the heat transfer depends mainly on the heat of reaction, because the rate of CH3COOH dissolution is smaller than that of HCl.