Direct Numerical Simulation of Single and Multiple Square Jets in Cross-FlowSource: Journal of Fluids Engineering:;2011:;volume( 133 ):;issue: 003::page 31201DOI: 10.1115/1.4003588Publisher: The American Society of Mechanical Engineers (ASME)
Abstract: Direct numerical simulations (DNSs) have been carried out for single and multiple square jets issuing normally into a cross-flow, with the primary aim of studying the flow structures and interaction mechanisms associated with the jet in cross-flow (JICF) problems. The single JICF configuration follows a similar study previously done by (2004, Phys. Rev. E, 69, p. 066302) and the multiple JICF configurations are arranged side-by-side in the spanwise direction with a jet-to-jet adjacent edge distance (H) for the twin-jet case and an additional third jet downstream along the centerline with a jet-to-jet adjacent edge distance (L) for the triple-jet case. Simulations are performed for two twin-jet cases with H=1D,2D, respectively, and for one triple-jet case with H=1D, L=2D, where D is the jet exit width. Flow conditions similar to Sau et al. are considered, i.e., the jet to the cross-flow velocity ratio R=2.5 and the Reynolds number 225, based on the freestream velocity and the jet exit width. For the single jet in cross-flow, the vortical structures from our DNS are in good qualitative agreement with the findings of Sau et al. For the side-by-side twin-jet configuration, results have shown that the merging process of the two initially separated counter-rotating vortex pairs (CRVPs) from each jet hole exit is strongly dependent on the jet-to-jet adjacent edge distance H with earlier merging observed for the case H=1D. Downstream, the flow is dominated by a larger CRVP structure, accompanied by a smaller inner vortex pair. The inner vortex pair is found not to survive in the far-field as it rapidly dissipates before exiting the computational domain. These observations are in good agreement with the experimental findings in the literature. Simulations of the triple-jet in cross-flow case have shown some complicated jet-jet and jet-cross-flow interactions with three vortex pairs observed downstream, significantly different from that seen in the twin-jet cases. The evidence of these flow structures and interaction characteristics could provide a valuable reference database for future in-depth flow physics studies of laboratory experimental and numerical investigations.
keyword(s): Flow (Dynamics) , Jets , Cross-flow , Computer simulation AND Vortices ,
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contributor author | Y. Yao | |
contributor author | M. Maidi | |
date accessioned | 2017-05-09T00:44:25Z | |
date available | 2017-05-09T00:44:25Z | |
date copyright | March, 2011 | |
date issued | 2011 | |
identifier issn | 0098-2202 | |
identifier other | JFEGA4-27454#031201_1.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl/handle/yetl/146370 | |
description abstract | Direct numerical simulations (DNSs) have been carried out for single and multiple square jets issuing normally into a cross-flow, with the primary aim of studying the flow structures and interaction mechanisms associated with the jet in cross-flow (JICF) problems. The single JICF configuration follows a similar study previously done by (2004, Phys. Rev. E, 69, p. 066302) and the multiple JICF configurations are arranged side-by-side in the spanwise direction with a jet-to-jet adjacent edge distance (H) for the twin-jet case and an additional third jet downstream along the centerline with a jet-to-jet adjacent edge distance (L) for the triple-jet case. Simulations are performed for two twin-jet cases with H=1D,2D, respectively, and for one triple-jet case with H=1D, L=2D, where D is the jet exit width. Flow conditions similar to Sau et al. are considered, i.e., the jet to the cross-flow velocity ratio R=2.5 and the Reynolds number 225, based on the freestream velocity and the jet exit width. For the single jet in cross-flow, the vortical structures from our DNS are in good qualitative agreement with the findings of Sau et al. For the side-by-side twin-jet configuration, results have shown that the merging process of the two initially separated counter-rotating vortex pairs (CRVPs) from each jet hole exit is strongly dependent on the jet-to-jet adjacent edge distance H with earlier merging observed for the case H=1D. Downstream, the flow is dominated by a larger CRVP structure, accompanied by a smaller inner vortex pair. The inner vortex pair is found not to survive in the far-field as it rapidly dissipates before exiting the computational domain. These observations are in good agreement with the experimental findings in the literature. Simulations of the triple-jet in cross-flow case have shown some complicated jet-jet and jet-cross-flow interactions with three vortex pairs observed downstream, significantly different from that seen in the twin-jet cases. The evidence of these flow structures and interaction characteristics could provide a valuable reference database for future in-depth flow physics studies of laboratory experimental and numerical investigations. | |
publisher | The American Society of Mechanical Engineers (ASME) | |
title | Direct Numerical Simulation of Single and Multiple Square Jets in Cross-Flow | |
type | Journal Paper | |
journal volume | 133 | |
journal issue | 3 | |
journal title | Journal of Fluids Engineering | |
identifier doi | 10.1115/1.4003588 | |
journal fristpage | 31201 | |
identifier eissn | 1528-901X | |
keywords | Flow (Dynamics) | |
keywords | Jets | |
keywords | Cross-flow | |
keywords | Computer simulation AND Vortices | |
tree | Journal of Fluids Engineering:;2011:;volume( 133 ):;issue: 003 | |
contenttype | Fulltext |