本文主要研究内容
作者罗伟（2019）在《环形逆向射流流场结构特性的模拟研究》一文中研究指出：逆向射流是火焰稳定的重要技术手段,为探究环形逆向射流结构对煤粉逆喷式旋流燃烧器稳燃特性的影响,构建了不同尺寸圆形与环形射流管的逆向射流模型,以Fluent软件为计算平台,采用"可实现"的k-ε模型对流场结构进行模拟研究。通过计算不同流速比下各射流管的无量纲贯入深度变化,发现环形射流的贯入深度大于圆形射流,且随内径的增大而增大,其射流在环境流中的渗透能力增强,这有利于增加煤粉的逆向传播距离,增加停留时间,提高燃烧稳定性。与圆形射流不同,环形射流的贯入深度与流速比并不是单调的线性关系,在流速比7.5～12.5存在一个平缓的过渡段,表明在一定区间内,流速比的减少不会引起贯入深度的明显减小,对现有燃烧器的设计具有指导意义。通过计算不同流速比下各射流管的最大零流速半宽,发现环形射流在逆流中的最大零流速半宽大于圆形射流,并随射流管内径增大而增大,表明环形逆向射流在径向的扩展宽度更大,卷吸能力更强。环形逆向射流的最大零流速半宽随流速比呈线性增大,斜率随内径增大而增加,高流速比的环形逆向射流径向扩展能力强于低流速比的环形逆向射流。根据计算结果绘制分界流线,发现在较低速度比时,射流的分界流线与圆形射流相似;在较高速度比时,虽然射流的轴线速度在滞点减少为零,但轴线附近的一定区域,流体依然向下游传播渗透,经过一段距离后速度才降至零并转向,分界流线也变得不规则。环境逆流在轴向上对环形射流有一定程度的压缩和阻碍作用,使得射流在径向的扩展宽度增大,增强了射流的卷吸能力,有助于促进燃烧器内煤粉与助燃风的混合。通过研究不同射流管逆向射流轴线上轴向流速的沿程变化,发现环形射流轴线上的流速衰减较圆形射流更为平缓,表明其与环境流的掺混不如圆形射流强烈。随着内径不断减小,环形射流轴向速度峰值增大且位置提前,衰减速度增强,逐渐接近圆形射流中轴线上的衰减情况。
Abstract
ni xiang she liu shi huo yan wen ding de chong yao ji shu shou duan ,wei tan jiu huan xing ni xiang she liu jie gou dui mei fen ni pen shi xuan liu ran shao qi wen ran te xing de ying xiang ,gou jian le bu tong che cun yuan xing yu huan xing she liu guan de ni xiang she liu mo xing ,yi Fluentruan jian wei ji suan ping tai ,cai yong "ke shi xian "de k-εmo xing dui liu chang jie gou jin hang mo ni yan jiu 。tong guo ji suan bu tong liu su bi xia ge she liu guan de mo liang gang guan ru shen du bian hua ,fa xian huan xing she liu de guan ru shen du da yu yuan xing she liu ,ju sui nei jing de zeng da er zeng da ,ji she liu zai huan jing liu zhong de shen tou neng li zeng jiang ,zhe you li yu zeng jia mei fen de ni xiang chuan bo ju li ,zeng jia ting liu shi jian ,di gao ran shao wen ding xing 。yu yuan xing she liu bu tong ,huan xing she liu de guan ru shen du yu liu su bi bing bu shi chan diao de xian xing guan ji ,zai liu su bi 7.5～12.5cun zai yi ge ping huan de guo du duan ,biao ming zai yi ding ou jian nei ,liu su bi de jian shao bu hui yin qi guan ru shen du de ming xian jian xiao ,dui xian you ran shao qi de she ji ju you zhi dao yi yi 。tong guo ji suan bu tong liu su bi xia ge she liu guan de zui da ling liu su ban kuan ,fa xian huan xing she liu zai ni liu zhong de zui da ling liu su ban kuan da yu yuan xing she liu ,bing sui she liu guan nei jing zeng da er zeng da ,biao ming huan xing ni xiang she liu zai jing xiang de kuo zhan kuan du geng da ,juan xi neng li geng jiang 。huan xing ni xiang she liu de zui da ling liu su ban kuan sui liu su bi cheng xian xing zeng da ,xie lv sui nei jing zeng da er zeng jia ,gao liu su bi de huan xing ni xiang she liu jing xiang kuo zhan neng li jiang yu di liu su bi de huan xing ni xiang she liu 。gen ju ji suan jie guo hui zhi fen jie liu xian ,fa xian zai jiao di su du bi shi ,she liu de fen jie liu xian yu yuan xing she liu xiang shi ;zai jiao gao su du bi shi ,sui ran she liu de zhou xian su du zai zhi dian jian shao wei ling ,dan zhou xian fu jin de yi ding ou yu ,liu ti yi ran xiang xia you chuan bo shen tou ,jing guo yi duan ju li hou su du cai jiang zhi ling bing zhuai xiang ,fen jie liu xian ye bian de bu gui ze 。huan jing ni liu zai zhou xiang shang dui huan xing she liu you yi ding cheng du de ya su he zu ai zuo yong ,shi de she liu zai jing xiang de kuo zhan kuan du zeng da ,zeng jiang le she liu de juan xi neng li ,you zhu yu cu jin ran shao qi nei mei fen yu zhu ran feng de hun ge 。tong guo yan jiu bu tong she liu guan ni xiang she liu zhou xian shang zhou xiang liu su de yan cheng bian hua ,fa xian huan xing she liu zhou xian shang de liu su cui jian jiao yuan xing she liu geng wei ping huan ,biao ming ji yu huan jing liu de can hun bu ru yuan xing she liu jiang lie 。sui zhao nei jing bu duan jian xiao ,huan xing she liu zhou xiang su du feng zhi zeng da ju wei zhi di qian ,cui jian su du zeng jiang ,zhu jian jie jin yuan xing she liu zhong zhou xian shang de cui jian qing kuang 。
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论文作者分别是来自洁净煤技术的罗伟，发表于刊物洁净煤技术2019年05期论文，是一篇关于逆向射流论文,环形论文,流场结构论文,稳燃论文,数值模拟论文,洁净煤技术2019年05期论文的文章。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，资料来自洁净煤技术2019年05期论文网站，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。