Experimental studies on the Hartmann tube

E. Rathakrishnan
{"title":"Experimental studies on the Hartmann tube","authors":"E. Rathakrishnan","doi":"10.1017/aer.2024.34","DOIUrl":null,"url":null,"abstract":"\n The effect of tube depth, the separation distance between the tube and nozzle exit, and the nozzle pressure ratio on the characteristics of the flow coming out of the Hartmann tube was studied experimentally. The configuration used in this work consists of an underexpanded sonic jet emanating from a convergent nozzle directed into a closed-ended cylindrical tube of the same diameter (D) as the nozzle exit. The nozzle was operated at two levels of underexpansion corresponding to nozzle pressure ratio (NPR) 3 and 5. The distance (S) from nozzle exit and tube inlet was varied from 0.4D to 4D. Discrete high-amplitude tones (the jet regurgitant, JRG) were produced, only at certain (periodic) intervals (near the shock-cell terminations) of spacing for NPR 3, while for NPR 5 the JRG tones are produced at all points beyond the first shock-cell. For locations other than these, high-frequency tones (screech mode) were observed. The connection between the jet structure and operating modes revealed that the location of standoff shock ahead of the tube with respect to the jet structure plays a dominant role in the observed ‘modes’ rather than the nozzle tube separation. The results reveal that the frequency response of longer tubes in JRG mode approaches their quarter wave frequencies. The high-frequency oscillations observed in the screech mode showed independency with cavity (pipe) depth, contrary to the available literature, the transition between ‘different modes’ oscillation is a function of cavity depth.","PeriodicalId":508971,"journal":{"name":"The Aeronautical Journal","volume":"61 2","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Aeronautical Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1017/aer.2024.34","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

Abstract

The effect of tube depth, the separation distance between the tube and nozzle exit, and the nozzle pressure ratio on the characteristics of the flow coming out of the Hartmann tube was studied experimentally. The configuration used in this work consists of an underexpanded sonic jet emanating from a convergent nozzle directed into a closed-ended cylindrical tube of the same diameter (D) as the nozzle exit. The nozzle was operated at two levels of underexpansion corresponding to nozzle pressure ratio (NPR) 3 and 5. The distance (S) from nozzle exit and tube inlet was varied from 0.4D to 4D. Discrete high-amplitude tones (the jet regurgitant, JRG) were produced, only at certain (periodic) intervals (near the shock-cell terminations) of spacing for NPR 3, while for NPR 5 the JRG tones are produced at all points beyond the first shock-cell. For locations other than these, high-frequency tones (screech mode) were observed. The connection between the jet structure and operating modes revealed that the location of standoff shock ahead of the tube with respect to the jet structure plays a dominant role in the observed ‘modes’ rather than the nozzle tube separation. The results reveal that the frequency response of longer tubes in JRG mode approaches their quarter wave frequencies. The high-frequency oscillations observed in the screech mode showed independency with cavity (pipe) depth, contrary to the available literature, the transition between ‘different modes’ oscillation is a function of cavity depth.
哈特曼管实验研究
实验研究了管子深度、管子与喷嘴出口之间的分离距离以及喷嘴压力比对哈特曼管内气流特性的影响。这项工作中使用的配置包括一个从会聚喷嘴喷射出的未充分膨胀的声波射流,射流进入一个封闭的圆柱形管内,该管的直径(D)与喷嘴出口的直径相同。喷嘴在两个低膨胀水平下运行,分别对应于喷嘴压力比 (NPR) 3 和 5。喷嘴出口与管道入口的距离(S)从 0.4D 到 4D 不等。对于 NPR 3,仅在某些(周期性)间隔(靠近冲击单元终端)产生离散的高振幅音调(喷射回流音,JRG),而对于 NPR 5,在第一个冲击单元以外的所有位置都会产生 JRG 音调。而在 NPR 5 中,第一个冲击单元以外的所有位置都会产生 JRG 音调,除此之外的位置则会出现高频音调(尖啸声模式)。喷射结构与运行模式之间的联系表明,相对于喷射结构而言,喷管前方的对峙冲击位置在观察到的 "模式 "中起着主导作用,而不是喷管分离。结果显示,在 JRG 模式下,较长喷管的频率响应接近其四分之一波频率。在尖啸模式中观察到的高频振荡与空腔(管道)深度无关,这与现有文献中 "不同模式 "振荡之间的过渡是空腔深度的函数相反。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信