Control of Laminar Separation Bubble using Vortex Generators

In this paper, the performance of sub boundary layer vortex generators and conventional vortex generators in controlling the separation bubble has been compared and the resultant highly three-dimensional flow has been studied. Two pairs of vortex generators mounted symmetrically along the spanwise d...

Full description

Bibliographic Details
Main Author: N. K. Singh
Format: Article
Language:English
Published: Isfahan University of Technology 2019-01-01
Series:Journal of Applied Fluid Mechanics
Subjects:
Online Access:http://jafmonline.net/JournalArchive/download?file_ID=49115&issue_ID=256
_version_ 1818807680223936512
author N. K. Singh
author_facet N. K. Singh
author_sort N. K. Singh
collection DOAJ
description In this paper, the performance of sub boundary layer vortex generators and conventional vortex generators in controlling the separation bubble has been compared and the resultant highly three-dimensional flow has been studied. Two pairs of vortex generators mounted symmetrically along the spanwise direction are placed upstream of separation point to produce counter-rotating vortices. Effect of these three-dimensional vortex generators on the separation bubble and the flow downstream has been examined. The simulations show that the length of the separation bubble is reduced by sixty two per cent due to the deployment of vortex generators of height 0.33 δ while the original separation bubble is completely eliminated by the vortex generators of height 0.66 δ. However the presence of larger height vortex generators by itself causes a small mean separation bubble downstream. The flow downstream of vortex generators is highly three-dimensional and zones of recirculation can be observed between regions of attached flow. Presence of adverse pressure gradient results in greater interaction between counter-rotating vortices, leading to their early breakup and higher vortex decay rate compared to the zero pressure gradient case. Further, it is seen from the simulations that the counter-rotating array of vortices does not move away from the wall even far downstream.
first_indexed 2024-12-18T19:29:31Z
format Article
id doaj.art-d570d458b1c24a0491de0ccae1b78e05
institution Directory Open Access Journal
issn 1735-3572
language English
last_indexed 2024-12-18T19:29:31Z
publishDate 2019-01-01
publisher Isfahan University of Technology
record_format Article
series Journal of Applied Fluid Mechanics
spelling doaj.art-d570d458b1c24a0491de0ccae1b78e052022-12-21T20:55:47ZengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722019-01-01123891905.Control of Laminar Separation Bubble using Vortex GeneratorsN. K. Singh0Department of Mechanical Engineering, National Institute of Technology, Kurukshetra, Haryana, 136119, IndiaIn this paper, the performance of sub boundary layer vortex generators and conventional vortex generators in controlling the separation bubble has been compared and the resultant highly three-dimensional flow has been studied. Two pairs of vortex generators mounted symmetrically along the spanwise direction are placed upstream of separation point to produce counter-rotating vortices. Effect of these three-dimensional vortex generators on the separation bubble and the flow downstream has been examined. The simulations show that the length of the separation bubble is reduced by sixty two per cent due to the deployment of vortex generators of height 0.33 δ while the original separation bubble is completely eliminated by the vortex generators of height 0.66 δ. However the presence of larger height vortex generators by itself causes a small mean separation bubble downstream. The flow downstream of vortex generators is highly three-dimensional and zones of recirculation can be observed between regions of attached flow. Presence of adverse pressure gradient results in greater interaction between counter-rotating vortices, leading to their early breakup and higher vortex decay rate compared to the zero pressure gradient case. Further, it is seen from the simulations that the counter-rotating array of vortices does not move away from the wall even far downstream.http://jafmonline.net/JournalArchive/download?file_ID=49115&issue_ID=256Laminar separation bubble; Rectangular vortex generators; Direct numerical simulation; Immersed boundary method.
spellingShingle N. K. Singh
Control of Laminar Separation Bubble using Vortex Generators
Journal of Applied Fluid Mechanics
Laminar separation bubble; Rectangular vortex generators; Direct numerical simulation; Immersed boundary method.
title Control of Laminar Separation Bubble using Vortex Generators
title_full Control of Laminar Separation Bubble using Vortex Generators
title_fullStr Control of Laminar Separation Bubble using Vortex Generators
title_full_unstemmed Control of Laminar Separation Bubble using Vortex Generators
title_short Control of Laminar Separation Bubble using Vortex Generators
title_sort control of laminar separation bubble using vortex generators
topic Laminar separation bubble; Rectangular vortex generators; Direct numerical simulation; Immersed boundary method.
url http://jafmonline.net/JournalArchive/download?file_ID=49115&issue_ID=256
work_keys_str_mv AT nksingh controloflaminarseparationbubbleusingvortexgenerators