本文主要研究内容
作者何昌鸿（2019）在《基于动力学模态分解的离心泵内部流场流动特征数值研究》一文中研究指出：液下式离心泵是化工行业的生产系统中的核心部件,保证液下式离心泵的安全稳定运行是我们所要面对的关键问题。离心泵内的不稳定流动往往会诱发泵内振动和噪声的产生从而影响到离心泵的稳定性运行。因此,深入研究离心泵内的不稳定流动现象,将有助于我们改善液下式离心泵的运行环境,进而使其能更加稳定可靠的进行工作。本文以某型号的液下式离心泵为研究对象,利用数值计算方法和动力学模态分解方法(DMD)对其内部流场的不稳定流动现象进行研究。本文主要做了以下的研究工作:首先,通过数值模拟方法计算了该液下式离心泵内部流场的流动规律,同时对比了该离心泵在数值计算下和试验结果下的外特性变化规律。结果表明,数值计算和试验所得到的液下泵的外特性曲线的吻合度很高,两种方法所得的扬程、轴功率和效率随流量曲线的变化趋势基本一致。小流量工况下时,该泵内部流动状态最差,靠近隔舌和隔板入口附近的压力分布较为杂乱,且湍动能值较大的区域主要集中这两个区域处。大流量工况下时,随着流量的不断增大,蜗壳出口的回流现象越来越明显,并且在隔板入口处也逐渐出现了回流现象。其次,在定常计算的基础上,对0.6Q_d、1.0Q_d、1.4Q_d三种流量工况下的离心泵内部流场进行了非定常计算,同时选取了一系列的监测点对该离心泵内的压力脉动做了详细地研究。结果发现,叶轮叶片在通过同一圆周位置处时引起的压力脉动是基本相同的,且动静干涉是引起叶轮流道内压力脉动的最主要因素。蜗壳内各监测点处的压力脉动的最大幅值均出现在叶频处,且蜗壳隔舌处的压力脉动幅值最大。从蜗壳隔舌处开始,沿着蜗壳螺旋段的方向至蜗壳第四断面时,各断面监测点上的最大脉动幅值依次减小,但在隔板入口处最高压力脉动幅值突然增加,而后依然沿着蜗壳螺旋段逐次减小。当流量减小时,蜗壳隔舌监测点处的压力脉动最大幅值出现在了小于1倍叶频处,这表明引起此处压力脉动的最主要原因已不再是叶轮和隔舌的动静干涉,而是此处流体的流动分离所引起。最后,在非定常计算所得的流场数据的基础上,在小流量工况和额定工况下,利用动力学模态分解方法对该液下泵的蜗壳内的流场结构进行了研究。其结果表明,通过DMD方法可以提取到该流场在特征频率和其他频率对应的流动模态,实现了对原始流场的降阶分析。两种工况下的第一阶模态都为原始流场中占主导地位的流动结构,两者的第二、三阶模态都为原始流场的主要振荡模态,并且其特征频率与FTT所得的1倍叶频和2倍叶频相一致,这证明叶轮与蜗壳的动静干涉是造成蜗壳内不稳定流动的主要原因。对比两种工况下的各阶模态速度云图可知,该离心泵的流量减小时,隔舌和隔板的存在会导致蜗壳内部更易发生低频的不稳定流动。
Abstract
ye xia shi li xin beng shi hua gong hang ye de sheng chan ji tong zhong de he xin bu jian ,bao zheng ye xia shi li xin beng de an quan wen ding yun hang shi wo men suo yao mian dui de guan jian wen ti 。li xin beng nei de bu wen ding liu dong wang wang hui you fa beng nei zhen dong he zao sheng de chan sheng cong er ying xiang dao li xin beng de wen ding xing yun hang 。yin ci ,shen ru yan jiu li xin beng nei de bu wen ding liu dong xian xiang ,jiang you zhu yu wo men gai shan ye xia shi li xin beng de yun hang huan jing ,jin er shi ji neng geng jia wen ding ke kao de jin hang gong zuo 。ben wen yi mou xing hao de ye xia shi li xin beng wei yan jiu dui xiang ,li yong shu zhi ji suan fang fa he dong li xue mo tai fen jie fang fa (DMD)dui ji nei bu liu chang de bu wen ding liu dong xian xiang jin hang yan jiu 。ben wen zhu yao zuo le yi xia de yan jiu gong zuo :shou xian ,tong guo shu zhi mo ni fang fa ji suan le gai ye xia shi li xin beng nei bu liu chang de liu dong gui lv ,tong shi dui bi le gai li xin beng zai shu zhi ji suan xia he shi yan jie guo xia de wai te xing bian hua gui lv 。jie guo biao ming ,shu zhi ji suan he shi yan suo de dao de ye xia beng de wai te xing qu xian de wen ge du hen gao ,liang chong fang fa suo de de yang cheng 、zhou gong lv he xiao lv sui liu liang qu xian de bian hua qu shi ji ben yi zhi 。xiao liu liang gong kuang xia shi ,gai beng nei bu liu dong zhuang tai zui cha ,kao jin ge she he ge ban ru kou fu jin de ya li fen bu jiao wei za luan ,ju tuan dong neng zhi jiao da de ou yu zhu yao ji zhong zhe liang ge ou yu chu 。da liu liang gong kuang xia shi ,sui zhao liu liang de bu duan zeng da ,luo ke chu kou de hui liu xian xiang yue lai yue ming xian ,bing ju zai ge ban ru kou chu ye zhu jian chu xian le hui liu xian xiang 。ji ci ,zai ding chang ji suan de ji chu shang ,dui 0.6Q_d、1.0Q_d、1.4Q_dsan chong liu liang gong kuang xia de li xin beng nei bu liu chang jin hang le fei ding chang ji suan ,tong shi shua qu le yi ji lie de jian ce dian dui gai li xin beng nei de ya li mai dong zuo le xiang xi de yan jiu 。jie guo fa xian ,xie lun xie pian zai tong guo tong yi yuan zhou wei zhi chu shi yin qi de ya li mai dong shi ji ben xiang tong de ,ju dong jing gan she shi yin qi xie lun liu dao nei ya li mai dong de zui zhu yao yin su 。luo ke nei ge jian ce dian chu de ya li mai dong de zui da fu zhi jun chu xian zai xie pin chu ,ju luo ke ge she chu de ya li mai dong fu zhi zui da 。cong luo ke ge she chu kai shi ,yan zhao luo ke luo xuan duan de fang xiang zhi luo ke di si duan mian shi ,ge duan mian jian ce dian shang de zui da mai dong fu zhi yi ci jian xiao ,dan zai ge ban ru kou chu zui gao ya li mai dong fu zhi tu ran zeng jia ,er hou yi ran yan zhao luo ke luo xuan duan zhu ci jian xiao 。dang liu liang jian xiao shi ,luo ke ge she jian ce dian chu de ya li mai dong zui da fu zhi chu xian zai le xiao yu 1bei xie pin chu ,zhe biao ming yin qi ci chu ya li mai dong de zui zhu yao yuan yin yi bu zai shi xie lun he ge she de dong jing gan she ,er shi ci chu liu ti de liu dong fen li suo yin qi 。zui hou ,zai fei ding chang ji suan suo de de liu chang shu ju de ji chu shang ,zai xiao liu liang gong kuang he e ding gong kuang xia ,li yong dong li xue mo tai fen jie fang fa dui gai ye xia beng de luo ke nei de liu chang jie gou jin hang le yan jiu 。ji jie guo biao ming ,tong guo DMDfang fa ke yi di qu dao gai liu chang zai te zheng pin lv he ji ta pin lv dui ying de liu dong mo tai ,shi xian le dui yuan shi liu chang de jiang jie fen xi 。liang chong gong kuang xia de di yi jie mo tai dou wei yuan shi liu chang zhong zhan zhu dao de wei de liu dong jie gou ,liang zhe de di er 、san jie mo tai dou wei yuan shi liu chang de zhu yao zhen dang mo tai ,bing ju ji te zheng pin lv yu FTTsuo de de 1bei xie pin he 2bei xie pin xiang yi zhi ,zhe zheng ming xie lun yu luo ke de dong jing gan she shi zao cheng luo ke nei bu wen ding liu dong de zhu yao yuan yin 。dui bi liang chong gong kuang xia de ge jie mo tai su du yun tu ke zhi ,gai li xin beng de liu liang jian xiao shi ,ge she he ge ban de cun zai hui dao zhi luo ke nei bu geng yi fa sheng di pin de bu wen ding liu dong 。
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论文详细介绍
论文作者分别是来自兰州理工大学的何昌鸿，发表于刊物兰州理工大学2019-07-18论文，是一篇关于液下式离心泵论文,数值计算论文,压力脉动论文,动力学模态分解论文,兰州理工大学2019-07-18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，资料来自兰州理工大学2019-07-18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：液下式离心泵论文; 数值计算论文; 压力脉动论文; 动力学模态分解论文; 兰州理工大学2019-07-18论文;