本文主要研究内容
作者陈铭（2019）在《水中气核演化及金属表面成核的微观机理》一文中研究指出：为了研究液体中气泡成核微观机理,避免空化对水力机械系统造成危害,本文以分子动力学技术为主要手段,运用多种水分子模型计算了水的物理性质,选用合适的水分子模型研究了纳米空气核在水中的稳定性,微观成核现象的演化过程,以及液态水在金属表面的成核现象,主要内容如下:1.在结合前人对水分子相图研究的基础上,计算分析对比不同水分子计算模型的特点与可应用范围。通过液氩比较平衡分子动力学与非平衡分子动力学计算精度,结论表明在物性参数计算方面,平衡分子动力学计算准确度高于非平衡分子动力学。对不同温度下SPC/E、SWM4-NDP、TIP3P、TIP4P、COMB3等水分子模型的黏度、热导率和扩散系数进行了分子动力学模拟,结果表明极化水分子模型SWM4-NDP、COMB3的模拟结果与实验误差总体上小于传统非极化刚性水分子模型。在刚性水分子模型中,TIP4P模型在不考虑相变、传热等因素的条件下模拟精确度相对较高。2.基于TIP4P刚性水分子模型,研究空气核在水中的稳定性,应用分子动力学的模拟方法,对存在空气核的水分子计算域进行了研究,得到了空气核在液态水中的瞬态特性并分析了影响其稳定性的关键因素,结果表明:具有一定质量的空气核能在液态水中维持动态平衡。在外界液体压力,空气核内压力和液体表面张力的共同作用下,空气核在水中逐渐达到动态平衡。一定体积的空气核内部密度存在使其稳定存在于水中的临界值,空气核质量与其平衡半径呈正相关,空气核在水中呈平衡态时核内密度与气核半径呈负相关。液体表面张力是影响空气核稳定性的重要因素。随着空气核半径的增大,液态水表面张力总体呈减小趋势。空气核初始半径越大,水压越小,越容易诱发空化初生。3.基于极化水分子模型SWM4-NDP,并应用分子动力学的模拟方法,研究了存在气穴的水分子计算域在成核过程中的密度分布,径向分布函数,分子偶极矩以及体系扩散系数,结果表明:在气核“初生”阶段,水中气穴体积逐渐增大发展为气核;在气核“融合”阶段,体系中产生出新的气核,气核相互融合成体积更大的气核;在气核“扩散”阶段,气核溃灭,气态水分子遍布整个体系,液态水分子变成团簇状。在气核“初生”阶段,双曲函数可以被用来拟合从气核中心向外的密度分布。温度影响成核时液态水相变的程度,温度高的体系成核时相变更为剧烈,因此体系也具有更大的扩散系数。4.基于COMB3极化水分子模型,并应用分子动力学的模拟方法,研究了液态水在铜金属表面的成核,发现当液态水受到拉应力而内部压力减小到负压时,在移动的金属表面上逐渐发生成核现象,当气核生长到一定体积后核内出现气态水分子。温度较低的体系中气核形状较为规则,温度较高的体系拥有较快的成核速率。成核过程中液态水体系的扩散系数逐渐增大,局部压力有规律性地剧烈波动,不同温度的体系成核过程中分子排布具有差异。
Abstract
wei le yan jiu ye ti zhong qi pao cheng he wei guan ji li ,bi mian kong hua dui shui li ji xie ji tong zao cheng wei hai ,ben wen yi fen zi dong li xue ji shu wei zhu yao shou duan ,yun yong duo chong shui fen zi mo xing ji suan le shui de wu li xing zhi ,shua yong ge kuo de shui fen zi mo xing yan jiu le na mi kong qi he zai shui zhong de wen ding xing ,wei guan cheng he xian xiang de yan hua guo cheng ,yi ji ye tai shui zai jin shu biao mian de cheng he xian xiang ,zhu yao nei rong ru xia :1.zai jie ge qian ren dui shui fen zi xiang tu yan jiu de ji chu shang ,ji suan fen xi dui bi bu tong shui fen zi ji suan mo xing de te dian yu ke ying yong fan wei 。tong guo ye ya bi jiao ping heng fen zi dong li xue yu fei ping heng fen zi dong li xue ji suan jing du ,jie lun biao ming zai wu xing can shu ji suan fang mian ,ping heng fen zi dong li xue ji suan zhun que du gao yu fei ping heng fen zi dong li xue 。dui bu tong wen du xia SPC/E、SWM4-NDP、TIP3P、TIP4P、COMB3deng shui fen zi mo xing de nian du 、re dao lv he kuo san ji shu jin hang le fen zi dong li xue mo ni ,jie guo biao ming ji hua shui fen zi mo xing SWM4-NDP、COMB3de mo ni jie guo yu shi yan wu cha zong ti shang xiao yu chuan tong fei ji hua gang xing shui fen zi mo xing 。zai gang xing shui fen zi mo xing zhong ,TIP4Pmo xing zai bu kao lv xiang bian 、chuan re deng yin su de tiao jian xia mo ni jing que du xiang dui jiao gao 。2.ji yu TIP4Pgang xing shui fen zi mo xing ,yan jiu kong qi he zai shui zhong de wen ding xing ,ying yong fen zi dong li xue de mo ni fang fa ,dui cun zai kong qi he de shui fen zi ji suan yu jin hang le yan jiu ,de dao le kong qi he zai ye tai shui zhong de shun tai te xing bing fen xi le ying xiang ji wen ding xing de guan jian yin su ,jie guo biao ming :ju you yi ding zhi liang de kong qi he neng zai ye tai shui zhong wei chi dong tai ping heng 。zai wai jie ye ti ya li ,kong qi he nei ya li he ye ti biao mian zhang li de gong tong zuo yong xia ,kong qi he zai shui zhong zhu jian da dao dong tai ping heng 。yi ding ti ji de kong qi he nei bu mi du cun zai shi ji wen ding cun zai yu shui zhong de lin jie zhi ,kong qi he zhi liang yu ji ping heng ban jing cheng zheng xiang guan ,kong qi he zai shui zhong cheng ping heng tai shi he nei mi du yu qi he ban jing cheng fu xiang guan 。ye ti biao mian zhang li shi ying xiang kong qi he wen ding xing de chong yao yin su 。sui zhao kong qi he ban jing de zeng da ,ye tai shui biao mian zhang li zong ti cheng jian xiao qu shi 。kong qi he chu shi ban jing yue da ,shui ya yue xiao ,yue rong yi you fa kong hua chu sheng 。3.ji yu ji hua shui fen zi mo xing SWM4-NDP,bing ying yong fen zi dong li xue de mo ni fang fa ,yan jiu le cun zai qi xue de shui fen zi ji suan yu zai cheng he guo cheng zhong de mi du fen bu ,jing xiang fen bu han shu ,fen zi ou ji ju yi ji ti ji kuo san ji shu ,jie guo biao ming :zai qi he “chu sheng ”jie duan ,shui zhong qi xue ti ji zhu jian zeng da fa zhan wei qi he ;zai qi he “rong ge ”jie duan ,ti ji zhong chan sheng chu xin de qi he ,qi he xiang hu rong ge cheng ti ji geng da de qi he ;zai qi he “kuo san ”jie duan ,qi he hui mie ,qi tai shui fen zi bian bu zheng ge ti ji ,ye tai shui fen zi bian cheng tuan cu zhuang 。zai qi he “chu sheng ”jie duan ,shuang qu han shu ke yi bei yong lai ni ge cong qi he zhong xin xiang wai de mi du fen bu 。wen du ying xiang cheng he shi ye tai shui xiang bian de cheng du ,wen du gao de ti ji cheng he shi xiang bian geng wei ju lie ,yin ci ti ji ye ju you geng da de kuo san ji shu 。4.ji yu COMB3ji hua shui fen zi mo xing ,bing ying yong fen zi dong li xue de mo ni fang fa ,yan jiu le ye tai shui zai tong jin shu biao mian de cheng he ,fa xian dang ye tai shui shou dao la ying li er nei bu ya li jian xiao dao fu ya shi ,zai yi dong de jin shu biao mian shang zhu jian fa sheng cheng he xian xiang ,dang qi he sheng chang dao yi ding ti ji hou he nei chu xian qi tai shui fen zi 。wen du jiao di de ti ji zhong qi he xing zhuang jiao wei gui ze ,wen du jiao gao de ti ji yong you jiao kuai de cheng he su lv 。cheng he guo cheng zhong ye tai shui ti ji de kuo san ji shu zhu jian zeng da ,ju bu ya li you gui lv xing de ju lie bo dong ,bu tong wen du de ti ji cheng he guo cheng zhong fen zi pai bu ju you cha yi 。
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论文详细介绍
论文作者分别是来自江苏大学的陈铭，发表于刊物江苏大学2019-09-19论文，是一篇关于水力机械论文,空化论文,气核论文,江苏大学2019-09-19论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自江苏大学2019-09-19论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：水力机械论文; 空化论文; 气核论文; 江苏大学2019-09-19论文;