Combustion simulations of AlH3 and ethanol nanofluid by ReaxFF
Yu-Xiao Cheng, Fengqi Zhao, Siyu Xu, Xue‐Hai Ju, Ying Zhao
Abstract
To alleviate the growing energy crisis, ethanol has been developed and applied gradually as an ideal biofuel to replace gasoline. The AlH 3 nanoparticle is an excellent fuel additive with broad applications. In this work, the ReaxFF-lg reactive dynamics simulations were proceeded to explore the detailed mechanisms of AlH 3 and ethanol nanofluid fuel. At varying temperatures, AlH 3 exhibits different morphologies: branch-like expansion at the lower temperatures; micro-explosion and reaggregation into larger clusters at high temperatures. Overall, AlH 3 accelerates the decomposition of ethanol and shortens the ignition delay. AlH 3 also reduces the activation energy for ethanol decomposition from 79.09 to 69.05 kJ/mol. The conversion of coordination number for Al-O bonds indicates that Al 2 O 3 is the final product of Al element. The simulation results reveal a new mechanism: AlH 3 promotes the dissociation of H in the hydroxyl, making the initial decomposition of ethanol to C 2 H 5 O (CH 3 CH 2 O, CH 3 CHOH and CH 2 CH 2 OH) selective. The released H forms more OH and HO 2 radicals to promote the conversion of intermediates to stable products. The Al 2 O 3 oxide layer delays the ethanol combustion kinetics as well. This study provides an atomic perspective on the combustion mechanisms of AlH 3 and ethanol nanofluid fuel and is expected to guide the development and application of AlH 3 -based fuels.