Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-28T20:57:31.381Z Has data issue: false hasContentIssue false

Flow and Dispersion Characteristics of a Stack-Issued Backward Inclined Jet in Crossflow

Published online by Cambridge University Press:  13 September 2016

M. G. Khouygani
Affiliation:
Department of Mechanical EngineeringNational Taiwan University of Science and TechnologyTaipei, Taiwan
R.-F. Huang*
Affiliation:
Department of Mechanical EngineeringNational Taiwan University of Science and TechnologyTaipei, Taiwan
C.-M. Hsu
Affiliation:
Graduate Institute of Applied Science and TechnologyNational Taiwan University of Science and TechnologyTaipei, Taiwan
*
*Corresponding author (rfhuang@mail.ntust.edu.tw)
Get access

Abstract

The effects of backward inclination angle on flow characteristics and jet dispersion properties of a stack-issued jet in crossflow were studied by means of instantaneous and long-exposure photography, particle image velocimetry (PIV), and tracer-gas concentration detections at a Reynolds number of 2,400, a jet-to-crossflow momentum flux ratio of 1.0, and the backward inclination angles θ = 0° - 60°. Three characteristic flow patterns featured by different near-wake flow structures were found within the surveyed span of the backward inclination angle: low (θ ≤ 25°), mediate (25° < θ < 50°), and high (θ ≥ 50°). In the range of low backward inclination angle, mushroom vortices appeared in the upwind shear layer. Jet fluids were entrained into the jet- and tube-wakes because the near wake region was characterized by a jet-wake vortex and a downwash flow. In the range of mediate backward inclination angle, forward-rolling vortices were formed in the upwind shear layer. Jet fluids were entrained into the jet wake but not appearing in the tube wake because the near wake was characterized by an isolated tube wake and up-going flows. In the range of high backward inclination angle, small-sized forward-rolling vortices were observed in the upwind shear layer. Jet fluids were not observed in both the jet- and tube-wakes because all flows went forward without reversal or vortex, which was similar to that in a jet in co-flow. Large turbulence intensities occurred around the jet-wake vortex and along sides of the tube wake bifurcation line, therefore the mixing at the low backward inclination angles presented better properties than those at mediate and high backward inclination angles owing to the featured flow structures and turbulence intensities.

Type
Research Article
Copyright
Copyright © The Society of Theoretical and Applied Mechanics 2017 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Mikolowsky, W. and McMahon, H., “An Experiments Investigation of a Jet Issuing from a Wing in Crossflow,” Journal of Aircraft, 10, pp. 546553 (1973).Google Scholar
2. Farvardin, E., Johnson, M., Alaee, H., Martinez, A., and Dolatabadi, A., , “Comparative Study of Biodiesel and Diesel Jets in Gaseous Crossflow,” Journal of Propulsion and Power, 29, pp. 12921302 (2013).Google Scholar
3. Fawcett, R. J., Wheeler, A. P. S., He, L. and Taylor, R., “Experimental Investigation into the Impact of Crossflow on the Coherent Unsteadiness within Film Cooling Flows,” International Journal of Heat and Fluid Flow, 40, pp. 3242 (2013).Google Scholar
4. Foust, J. and Rockwell, D., “Flow Structure Associated with Multiple Jets from a Generic Catheter Tip,” Journal of Experiments in Fluids, 42, pp. 513530 (2007).CrossRefGoogle Scholar
5. Hsu, C. M. and Huang, R. F., “Comparison of Flow and Mixing Characteristics between Unforced and Excited Elevated Transverse Jets,” Journal of Mechanics, 30, pp. 8796 (2014).Google Scholar
6. Moussa, Z. M., Trischka, J. W. and Eskinazi, S., “The Near Field in the Mixing of a Round Jet with a Cross-stream,” Journal of Fluid Mechanics, 80, pp. 4980 (1977).CrossRefGoogle Scholar
7. Eiff, O. S. and Keffer, J. F., “On the Structures in the Near-wake Region of an Elevated Turbulent Jet in a Crossflow,” Journal of Fluid Mechanics, 333, pp. 161195 (1997).Google Scholar
8. Smith, S. H. and Mungal, M. G., “Mixing, Structure and Scaling of the Jet in Crossflow,” Journal of Fluid Mechanics, 357, pp. 83122 (1998).CrossRefGoogle Scholar
9. Su, L. K. and Mungal, M. G., “Simultaneous Measurements of Scalar and Velocity Field Evolution in Turbulent Crossflowing Jets,” Journal of Fluid Mechanics, 513, pp. 145 (2004).CrossRefGoogle Scholar
10. Megerian, S., Davitian, J., Alves, L. S. de B. and Karagozian, A. R., “Transverse-Jet Shear-Layer Instabilities. Part 1. Experimental Studies,” Journal of Fluid Mechanics, 593, pp. 93129 (2007).CrossRefGoogle Scholar
11. Huang, R. F. and Lan, J., “Characteristic Modes and Evolution Processes of Shear-layer Vortices in an Elevated Transverse Jet,” Physics of Fluids, 17, pp. 113 (2005).Google Scholar
12. Khouygani, M. G., Huang, R. F. and Hsu, C. M., “Flow Characteristics in Median Plane of a Backward-Inclined Elevated Transverse Jet,” Experimental Thermal and Fluid Science, 62, pp. 164174 (2015).CrossRefGoogle Scholar
13. Sundararaj, S. and Selladurai, V., “Numerical and Experimental Study on Jet Trajectory and Mixing Behavior of Venturi-Jet Mixer,” Journal of Fluids Engineering, 132, pp. 19 (2010).Google Scholar
14. Adaramola, M. S., Sumner, D. and Bergstrom, D. J., “Turbulent Wake and Vortex Shedding for a Stack Partially Immersed in a Turbulent Boundary Layer,” Journal of Fluids and Structures, 23, pp. 11891206 (2007).Google Scholar
15. Coletti, F., Elkins, C. J. and Eaton, J. K., “An Inclined Jet in Crossflow under the Effect of Streamwise Pressure Gradients,” Experiments in Fluids, 54, 1589 (2013).CrossRefGoogle Scholar
16. Said, N. M., Habil, S., Mhiri, H., Bournot, H. and Le Palec, G., “Flow Field Measurement in a Crossflowing Elevated Jet,” Journal of Fluids Engineering, 129, pp. 551562 (2007).Google Scholar
17. Camussi, R., Guj, G. and Stella, A., “Experimental Study of a Jet in a Crossflow at Very Low Reynolds Number,” Journal of Fluid Mechanics, 454, pp. 113144 (2002).CrossRefGoogle Scholar
18. Huang, R. F. and Hsieh, R. H., “Sectional Flow Structures in Near Wake of Elevated Jets in Crossflow,” AIAA Journal, 41, pp. 14901499 (2003).Google Scholar
19. Huang, R. F. and Hsieh, R. H., “An Experimental Study of Elevated Round Jets Deflected in a Crosswind,” Experimental Thermal and Fluid Science, 27, pp. 7786 (2002).Google Scholar
20. Flagan, R. C. and Seinfield, J. H., Fundamental of Air Pollution Engineering, Prentice Hall, Englewood Cliffs, New Jersey, pp. 290357 (1988).Google Scholar
21. Keane, R. D. and Adrian, R. J., “Theory of Cross-correlation Analysis of PIV Images,” Applied Scientific Research, 49, pp. 191215 (1992).Google Scholar
22. Hart, D. P., “PIV Error Correction,” Experiments in Fluids, 29, pp. 1322 (2000).Google Scholar
23. Keane, R. D. and Adrian, R. J., “Optimization of Particle Image Velocimeters Part I: Double Pulsed Systems,” Measurement Science and Technology, 1, pp. 12021215 (1990).CrossRefGoogle Scholar
24. Steele, W. G., Taylor, R. P., Burrell, R. E. and Coleman, H. W., “Use of Previous Experience to Estimate Precision of Small Sample Uncertainty,” AIAA Journal, 31, pp. 18911896 (1993).CrossRefGoogle Scholar
25. Lighthill, M. J., , “Attachment and Separation in Three-Dimensional Flow,” Laminar Boundary Layers, Rosenhead, L., ed., Oxford University Press, Cambridge, pp. 7282 (1963).Google Scholar
26. Huang, R. F. and Hsu, C. M., “Flow and Mixing Characteristics of an Elevated Pulsating Transverse Jet,” Physics of Fluids, 24, pp. 015104-1∼21 (2012).Google Scholar