Lift and Tip Vortices Generated by Tapered Backward-Swept and Forward-Swept Wings under Stationary Ground ProximitySource: Journal of Aerospace Engineering:;2023:;Volume ( 036 ):;issue: 005::page 04023041-1DOI: 10.1061/JAEEEZ.ASENG-5054Publisher: ASCE
Abstract: An experimental investigation of the aerodynamics and near-field tip-vortex flow field behind tapered backward- and forward-swept wings with a stationary ground effect was conducted at Reynolds number (Re)=1.81×105. The results showed a large lift increase of 26.7% and 12.3% for the backward-swept wing (BSW) and forward-swept wing (FSW), respectively, with reduced ground clearance, along with a significant drag reduction of 45% and 30% for the BSW and FSW. For the BSW, a multiple-vortex system appeared in close ground proximity, consisting of a tip vortex, a corotating ground vortex, and a counterrotating secondary vortex. The ground vortex strengthens the tip vortex, whereas the secondary vortex negates its vorticity. For the FSW, the multiple-vortex system was not readily identifiable due to its unique geometry, which always keeps the inboard region of the wing at a close ground effect while leaving the tip region less affected by the ground effect. The root stall of the FSW also produced a continuously strengthening tip vortex with the increasing angle of attack. In contrast, the tip stall of the BSW led to a monotonically increasing vortex strength only up to the static-stall angle. Regardless of the wing model, the weak tip vortex also translates into a small lift-induced drag compared with the total drag. Finally, the lift force computed through the integration of the spanwise circulation distribution, inferred from the cross-flow measurements, at selected ground distances was also found to be in good agreement with the direct wind-tunnel force-balance data, with 101% and 98% consistency for BSW and FSW, respectively. The aerodynamics and tip-vortex measurements of both wing models outside the ground effect were also acquired to serve as a comparison.
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contributor author | G. Lin | |
contributor author | T. Lee | |
date accessioned | 2023-11-27T23:06:02Z | |
date available | 2023-11-27T23:06:02Z | |
date issued | 6/7/2023 12:00:00 AM | |
date issued | 2023-06-07 | |
identifier other | JAEEEZ.ASENG-5054.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl1/handle/yetl/4293288 | |
description abstract | An experimental investigation of the aerodynamics and near-field tip-vortex flow field behind tapered backward- and forward-swept wings with a stationary ground effect was conducted at Reynolds number (Re)=1.81×105. The results showed a large lift increase of 26.7% and 12.3% for the backward-swept wing (BSW) and forward-swept wing (FSW), respectively, with reduced ground clearance, along with a significant drag reduction of 45% and 30% for the BSW and FSW. For the BSW, a multiple-vortex system appeared in close ground proximity, consisting of a tip vortex, a corotating ground vortex, and a counterrotating secondary vortex. The ground vortex strengthens the tip vortex, whereas the secondary vortex negates its vorticity. For the FSW, the multiple-vortex system was not readily identifiable due to its unique geometry, which always keeps the inboard region of the wing at a close ground effect while leaving the tip region less affected by the ground effect. The root stall of the FSW also produced a continuously strengthening tip vortex with the increasing angle of attack. In contrast, the tip stall of the BSW led to a monotonically increasing vortex strength only up to the static-stall angle. Regardless of the wing model, the weak tip vortex also translates into a small lift-induced drag compared with the total drag. Finally, the lift force computed through the integration of the spanwise circulation distribution, inferred from the cross-flow measurements, at selected ground distances was also found to be in good agreement with the direct wind-tunnel force-balance data, with 101% and 98% consistency for BSW and FSW, respectively. The aerodynamics and tip-vortex measurements of both wing models outside the ground effect were also acquired to serve as a comparison. | |
publisher | ASCE | |
title | Lift and Tip Vortices Generated by Tapered Backward-Swept and Forward-Swept Wings under Stationary Ground Proximity | |
type | Journal Article | |
journal volume | 36 | |
journal issue | 5 | |
journal title | Journal of Aerospace Engineering | |
identifier doi | 10.1061/JAEEEZ.ASENG-5054 | |
journal fristpage | 04023041-1 | |
journal lastpage | 04023041-15 | |
page | 15 | |
tree | Journal of Aerospace Engineering:;2023:;Volume ( 036 ):;issue: 005 | |
contenttype | Fulltext |