本文關(guān)鍵詞： RP-3航空煤油 化學反應機理 過渡態(tài)計算 簡化機理 超聲速燃燒 仿真研究　出處：《北京交通大學》2017年碩士論文　論文類型：學位論文

【摘要】：由于具有超強動力特性,超燃沖壓發(fā)動機的軍事戰(zhàn)略地位極高,基于此,世界各國近年來開展了大量超聲速燃燒相關(guān)的研究工作,但超聲速燃燒仿真面臨著湍流與化學反應動力學的雙重困難,因而航空煤油的化學反應機理研究是超聲速燃燒的一個重要研究方向。本文通過對國產(chǎn)RP-3航空煤油進行研究,明確了其主要由鏈烷烴、芳香烴及環(huán)烷烴構(gòu)成,經(jīng)論證分析,采用正十二烷替代鏈烷烴組分,對二甲苯或乙基苯替代芳香烴組分,三甲基環(huán)己烷或丙基環(huán)己烷替代環(huán)烷烴組分,通過排列組合,共提出了四種不同組合的RP-3航空煤油替代燃料。對于多種組分構(gòu)成的替代燃料,本文采用大分子子機理加小分子核心機理的方法來構(gòu)建其化學反應機理。對于已有完整化學反應機理的組分:正十二烷、對二甲苯、乙基苯、三甲基環(huán)己烷,采用相關(guān)手段提取得到了它們的大分子子機理,而丙基環(huán)己烷則是通過Gaussian計算獲得了其大分子子機理,小分子核心機理采用的是比較通用的USC-Ⅱ機理。最終,與實驗結(jié)果驗證對比的結(jié)果表明由正十二烷、乙基苯及丙基環(huán)己烷構(gòu)成的替代燃料的機理較為適用。應用該機理進行超聲速燃燒仿真之前,為平衡CFD仿真的計算成本,本文首先采用ReaxRed程序包對詳細機理進行了 DGR簡化和CSP簡化,得到了一個85組分346步基元反應的簡化機理,然后利用主路徑分析的方法對大分子子機理進行簡化得到一個65組分264步反應的簡化機理,再采用ReaxRed程序包對簡化機理中的小分子部分進行簡化,最終得到一個43組分97步基元反應的簡化機理,并驗證了該簡化機理的適用性。本文采用簡化機理進行了 RP-3航空煤油在雙燃燒室沖壓發(fā)動機內(nèi)燃燒過程的研究,通過對比采用總包反應時超燃燃燒室內(nèi)燃燒流場的仿真結(jié)果,表明了采用簡化機理時燃燒室內(nèi)的燃料燃燒放熱過程更加合理。在此基礎上開展了亞燃燃燒室出口燃氣參數(shù)對超燃燃燒室內(nèi)燃燒流場的影響研究,結(jié)果表明亞燃燃燒室出口燃氣溫度增加時有利于超燃燃燒室內(nèi)的燃燒釋熱,而亞燃燃燒室出口燃氣馬赫數(shù)增加時,超燃燃燒室內(nèi)的燃燒效果變差。
[Abstract]:Because of its super dynamic characteristics, the military strategic position of scramjet is very high. Based on this, a large number of supersonic combustion related research work has been carried out in the world in recent years. But the supersonic combustion simulation is faced with the dual difficulties of turbulence and chemical reaction dynamics. Therefore, the study of chemical reaction mechanism of aviation kerosene is an important research direction of supersonic combustion. In this paper, through the study of domestic RP-3 aviation kerosene, it is clear that the alkane is the main component of aviation kerosene. The composition of aromatic hydrocarbon and naphthenic hydrocarbon was proved and analyzed. 12 alkanes were substituted for alkane component, p-xylene or ethylbenzene for aromatic hydrocarbon component, trimethylcyclohexane or propyl cyclohexane for naphthenic hydrocarbon component. Through arrangement and combination, four different combinations of RP-3 aviation kerosene alternative fuels are proposed. In this paper, the macromolecular mechanism and small molecular core mechanism were used to construct the chemical reaction mechanism. For the components of the existing complete chemical reaction mechanism: 12 alkane, p-xylene, ethyl benzene, trimethyl cyclohexane. Their macromolecular mechanism was extracted by correlation method, while propanyl cyclohexane was obtained by Gaussian calculation. The core mechanism of small molecule is USC- 鈪，

本文編號：1445496