Near-field of coaxial jets with large density differences

被引:22
作者
Favre-Marinet, M
Camano, EB
Sarboch, J
机构
[1] Inst Mecan Grenoble, Lab Ecoulements Geophys & Ind, INPG, UJF,CNRS, F-38041 Grenoble, France
[2] Univ Fed Rio Grande do Sul, Inst Pesquisas Hidraul, BR-91501970 Porto Alegre, RS, Brazil
[3] Czech Tech Univ, Fac Mech Engn, Dept Fluid Mech & Thermodynam K 212, CR-16635 Prague, Czech Republic
关键词
D O I
10.1007/s003480050268
中图分类号
TH [机械、仪表工业];
学科分类号
0802 ;
摘要
The paper describes an experimental investigation of coaxial jets with large density differences. Measurements by various techniques show that density effects on the flow dynamics are taken into account to first order by considering the specific outer to inner jet momentum flux ratio M and not separately the density and velocity ratios. A regime of recirculation occurs for M higher than a critical value (M(c) approximate to 50). For a given value of M, however, the position of the recirculation bubble is slightly shifted in the upstream direction for density ratios much smaller than one. An unexpected result is obtained for an extremely low density ratio: the onset of recirculation occurs for a significantly higher value of M (100 < M(c) < 140) for helium/SF(6) jets (density ratio:0.028).
引用
收藏
页码:97 / 106
页数:10
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