ReaxFF MD方法揭示的JP-10热解吸热与氧化放热机理  

Pyrolysis endothermic and oxidative exothermic mechanisms of JP-10 unraveled by ReaxFF molecular dynamics simulation

作　　者：刘晗 肖媛媛 郑默[1,2] 任春醒 李晓霞 LIU Han;XIAO Yuanyuan;ZHENG Mo;REN Chunxing;LI Xiaoxia(State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China;School of Chemical Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院过程工程研究所介科学与工程全国重点实验室,北京100190 [2]中国科学院大学化学工程学院,北京100049

出　　处：《火箭推进》2024年第5期53-64,共12页Journal of Rocket Propulsion

基　　金：国家自然科学基金(22173106,22279145);中国科学院战略性先导科技专项(XDA0390502)。

摘　　要：认识裂解吸热和氧化放热反应机理对发展高超声速飞行器所需要的吸热型碳氢燃料极为重要。通过基于ReaxFF力场的反应分子动力学模拟(ReaxFF MD),揭示了JP-10热裂解吸热与氧化放热的微观反应机理。升温模拟结果表明,JP-10氧化体系总反应热效应由吸热转变为放热的转折点在2600 K附近,吸热阶段开环反应的吸热量约占总吸热量的64%。在JP-10氧化阶段,H自由基和O_(2)反应生成HO_(2),进而生成HO自由基以及含氧自由基生成H_(2)O的反应会大量释热,约占总放热量的54%。结果表明:基于ReaxFF MD模拟、通过反应热分析识别重要反应是一种有潜力认识燃料分子结构对燃料裂解吸热能力及裂解产物组成对燃料氧化释热能力影响规律的新途径。Understanding the mechanisms of pyrolysis endothermic and oxidative exothermic reactions is vital in developing endothermic hydrocarbon fuel in reducing engine surface temperature of hypersonic vehicle.In this paper,the reaction mechanisms of endothermic and exothermic processes were revealed for the widely used endothermic fuel of JP-10 by ReaxFF molecular dynamics simulations(ReaxFF MD).The heat-up simulation results show that the transition point from endothermic to exothermic for the total reaction heat effect of JP-10 oxidation system is around 2600 K.The absorbed heat of the ring-opening reactions in the endothermic stage accounts for about 64%of the total heat absorption.The stepwise reactions of H free radicals and O_(2)into HO_(2)and HO free radicals,and HO_(2)and HO into H_(2)O will release a large amount of heat,accounting for about 54%of the total heat release in the oxidation stage.This work demonstrates that reaction energy analysis of ReaxFF MD simulations is potentially a new approach for identifying important reaction pathways and understanding the effects of fuel molecular structures on fuel endothermic capacity and fuel pyrolyzate composition on fuel oxidative exothermic capacity.

关 键 词：吸热型碳氢燃料 分子动力学模拟 REAXFF JP-10 吸热反应机理 氧化反应机理 

分 类 号：V312.1[航空宇航科学与技术—航空宇航推进理论与工程]