The Application of Synthetic Jet Actuators for the Modification of the Characteristics of Separated Shear Layers

Mark Watson, Artur J. Jaworski, Norman J. Wood

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This paper presents an experimental investigation related to controlling the unsteady characteristics of the separated shear layers occurring over highly swept wings, and in particular focuses on application of synthetic jet actuators for modification of unsteady dynamic loading on the wing surface due to the phenomenon referred to as vortex breakdown (burst). In the post burst flow region the surface pressure measurements reveal the presence of certain characteristic spectral peaks that are thought to represent the presence of a spiralling filament of vorticity inside the expanded vortex that is known to be present in the burst flow over swept wings. This paper details an investigation into how the use of an array of 18 discrete synthetic jet actuators, distributed along the leading edge of a delta wing with a 60° sweep angle, can be used to alter the spectral content of this unsteadiness and reduce the level of unsteady pressure found in the post-burst region toward the wing trailing edge by up to 40%. Measurements of the surface pressure spectral distributions over the wing are presented together with PIV measurements of the vortex cross-section, conducted in the successive planes parallel to the wing trailing edge. Additional surface flow visualisation indicates that the effect of the actuators on the leading edge boundary layer is to induce local separation delays close to each actuator orifice, which introduce “ripples” into the shear layer as it separates. The results obtained are used to formulate an interpretative hypothesis attempting to explain the mechanisms responsible for modification of the spectral content and the level of excitation measured on the wing surface.
Original languageEnglish
Title of host publicationASME 7th Biennial Conference on Engineering Systems Design and Analysis
PublisherAmerican Society of Mechanical Engineers (ASME)
Pages959-968
Number of pages10
Volume1
ISBN (Electronic)0791837416
ISBN (Print)0791841731
DOIs
Publication statusPublished - 19 Jul 2004
Externally publishedYes
EventThe American Society of Mechanical Engineers Biennial Conference on Engineering Systems Design and Analysis - Manchester, United Kingdom
Duration: 19 Jul 200422 Jul 2004
Conference number: 7
http://proceedings.asmedigitalcollection.asme.org/volume.aspx?conferenceid=3042&volumeid=15363 (Link to Conference Proceedings)

Conference

ConferenceThe American Society of Mechanical Engineers Biennial Conference on Engineering Systems Design and Analysis
CountryUnited Kingdom
CityManchester
Period19/07/0422/07/04
Internet address

Fingerprint

Actuators
Swept wings
Vortex flow
Surface measurement
Flow visualization
Pressure measurement
Orifices
Vorticity
Boundary layers

Cite this

Watson, M., Jaworski, A. J., & Wood, N. J. (2004). The Application of Synthetic Jet Actuators for the Modification of the Characteristics of Separated Shear Layers. In ASME 7th Biennial Conference on Engineering Systems Design and Analysis (Vol. 1, pp. 959-968). [ESDA2004-58561] American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/ESDA2004-58561
Watson, Mark ; Jaworski, Artur J. ; Wood, Norman J. / The Application of Synthetic Jet Actuators for the Modification of the Characteristics of Separated Shear Layers. ASME 7th Biennial Conference on Engineering Systems Design and Analysis. Vol. 1 American Society of Mechanical Engineers (ASME), 2004. pp. 959-968
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abstract = "This paper presents an experimental investigation related to controlling the unsteady characteristics of the separated shear layers occurring over highly swept wings, and in particular focuses on application of synthetic jet actuators for modification of unsteady dynamic loading on the wing surface due to the phenomenon referred to as vortex breakdown (burst). In the post burst flow region the surface pressure measurements reveal the presence of certain characteristic spectral peaks that are thought to represent the presence of a spiralling filament of vorticity inside the expanded vortex that is known to be present in the burst flow over swept wings. This paper details an investigation into how the use of an array of 18 discrete synthetic jet actuators, distributed along the leading edge of a delta wing with a 60° sweep angle, can be used to alter the spectral content of this unsteadiness and reduce the level of unsteady pressure found in the post-burst region toward the wing trailing edge by up to 40{\%}. Measurements of the surface pressure spectral distributions over the wing are presented together with PIV measurements of the vortex cross-section, conducted in the successive planes parallel to the wing trailing edge. Additional surface flow visualisation indicates that the effect of the actuators on the leading edge boundary layer is to induce local separation delays close to each actuator orifice, which introduce “ripples” into the shear layer as it separates. The results obtained are used to formulate an interpretative hypothesis attempting to explain the mechanisms responsible for modification of the spectral content and the level of excitation measured on the wing surface.",
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Watson, M, Jaworski, AJ & Wood, NJ 2004, The Application of Synthetic Jet Actuators for the Modification of the Characteristics of Separated Shear Layers. in ASME 7th Biennial Conference on Engineering Systems Design and Analysis. vol. 1, ESDA2004-58561, American Society of Mechanical Engineers (ASME), pp. 959-968, The American Society of Mechanical Engineers Biennial Conference on Engineering Systems Design and Analysis, Manchester, United Kingdom, 19/07/04. https://doi.org/10.1115/ESDA2004-58561

The Application of Synthetic Jet Actuators for the Modification of the Characteristics of Separated Shear Layers. / Watson, Mark; Jaworski, Artur J.; Wood, Norman J.

ASME 7th Biennial Conference on Engineering Systems Design and Analysis. Vol. 1 American Society of Mechanical Engineers (ASME), 2004. p. 959-968 ESDA2004-58561.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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T1 - The Application of Synthetic Jet Actuators for the Modification of the Characteristics of Separated Shear Layers

AU - Watson, Mark

AU - Jaworski, Artur J.

AU - Wood, Norman J.

PY - 2004/7/19

Y1 - 2004/7/19

N2 - This paper presents an experimental investigation related to controlling the unsteady characteristics of the separated shear layers occurring over highly swept wings, and in particular focuses on application of synthetic jet actuators for modification of unsteady dynamic loading on the wing surface due to the phenomenon referred to as vortex breakdown (burst). In the post burst flow region the surface pressure measurements reveal the presence of certain characteristic spectral peaks that are thought to represent the presence of a spiralling filament of vorticity inside the expanded vortex that is known to be present in the burst flow over swept wings. This paper details an investigation into how the use of an array of 18 discrete synthetic jet actuators, distributed along the leading edge of a delta wing with a 60° sweep angle, can be used to alter the spectral content of this unsteadiness and reduce the level of unsteady pressure found in the post-burst region toward the wing trailing edge by up to 40%. Measurements of the surface pressure spectral distributions over the wing are presented together with PIV measurements of the vortex cross-section, conducted in the successive planes parallel to the wing trailing edge. Additional surface flow visualisation indicates that the effect of the actuators on the leading edge boundary layer is to induce local separation delays close to each actuator orifice, which introduce “ripples” into the shear layer as it separates. The results obtained are used to formulate an interpretative hypothesis attempting to explain the mechanisms responsible for modification of the spectral content and the level of excitation measured on the wing surface.

AB - This paper presents an experimental investigation related to controlling the unsteady characteristics of the separated shear layers occurring over highly swept wings, and in particular focuses on application of synthetic jet actuators for modification of unsteady dynamic loading on the wing surface due to the phenomenon referred to as vortex breakdown (burst). In the post burst flow region the surface pressure measurements reveal the presence of certain characteristic spectral peaks that are thought to represent the presence of a spiralling filament of vorticity inside the expanded vortex that is known to be present in the burst flow over swept wings. This paper details an investigation into how the use of an array of 18 discrete synthetic jet actuators, distributed along the leading edge of a delta wing with a 60° sweep angle, can be used to alter the spectral content of this unsteadiness and reduce the level of unsteady pressure found in the post-burst region toward the wing trailing edge by up to 40%. Measurements of the surface pressure spectral distributions over the wing are presented together with PIV measurements of the vortex cross-section, conducted in the successive planes parallel to the wing trailing edge. Additional surface flow visualisation indicates that the effect of the actuators on the leading edge boundary layer is to induce local separation delays close to each actuator orifice, which introduce “ripples” into the shear layer as it separates. The results obtained are used to formulate an interpretative hypothesis attempting to explain the mechanisms responsible for modification of the spectral content and the level of excitation measured on the wing surface.

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KW - Shear (Mechanics)

U2 - 10.1115/ESDA2004-58561

DO - 10.1115/ESDA2004-58561

M3 - Conference contribution

SN - 0791841731

VL - 1

SP - 959

EP - 968

BT - ASME 7th Biennial Conference on Engineering Systems Design and Analysis

PB - American Society of Mechanical Engineers (ASME)

ER -

Watson M, Jaworski AJ, Wood NJ. The Application of Synthetic Jet Actuators for the Modification of the Characteristics of Separated Shear Layers. In ASME 7th Biennial Conference on Engineering Systems Design and Analysis. Vol. 1. American Society of Mechanical Engineers (ASME). 2004. p. 959-968. ESDA2004-58561 https://doi.org/10.1115/ESDA2004-58561