Active Control of High Subsonic Jets

Kim, Jin-Hwa; Kastner, Jeff; Utkin, Yurii; Adamovich, Igor; Samimy, Mo

doi:10.2514/6.2007-320

Cited by 13 publications

(29 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This suggests that the pairing did not occur in an orderly manner so that the coupling of the two modes perhaps did not happen [Ginevsky, et al 2004]. Based on earlier results in Mach 0.9 subsonic [Kim et al 2009] and Mach 1.3 supersonic [Samimy et al 2007b] jets, it seems that the jet column mode is directly forced by the actuators.…”

Section: Introductionmentioning

confidence: 90%

“…The jet column instability is unstable to azimuthal or helical modes [Cohen & Wygnanski 1987]. In a Mach 0.9 subsonic jet, the effects of azimuthal modes were maximum near the jet column instability frequency [Kim et al 2007[Kim et al & 2009.…”

Section: Introductionmentioning

confidence: 99%

“…However, the actuators appeared to lack control authority at higher Mach numbers, as only 8 actuators, which had been designed for much smaller jet at GDTL, were used. In an axisymmetric Mach 0.9 jet, the effects of forcing frequency and mode were explained by using vortex dynamics [Kim et al 2007[Kim et al , 2009. The pattern of structures, as well as their spacing and size, were strongly dependant on the forcing frequency and mode.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Active Control on the Flow Structure in a High Reynolds Number Supersonic Jet

Kim¹,

Samimy²

2009

International Journal of Flow Control

Self Cite

View full text Add to dashboard Cite

A supersonic axisymmetric jet of design Mach number 1.3 operated in perfectly-and imperfectly-expanded flow regimes is excited by using localized arc filament plasma actuators (LAFPAs). The jet is operated at three fully-expanded jet Mach numbers (M J) of 1.2 (over-expanded), 1.3 (perfectly-expanded), and 1.4 (under-expanded). The Reynolds number based on the jet diameter and jet exit velocity ranges from 1.1x10 6 to 1.4x10 6. Eight equally-spaced LAFPAs are housed in a boron nitride nozzle extension. The forcing Strouhal number is ranged from 0.07 to 2.62 for azimuthal modes of 0-3, ±1, ±2, and ±4. In the perfectly-expanded jet, the most effective forcing is obtained at m = ±1 and the jet spreading is significantly enhanced at a forcing Strouhal number of about 0.3 at this mode. For the perfectly-expanded jet, the effects of forcing on the jet development and structure formation are very similar to those observed in a M J = 0.9 subsonic jet, which has been investigated previously. However, the generated structures in the imperfectly-expanded jets are less energetic due to the competition for energy between the perturbations seeded by the actuators and naturally existing perturbations amplified by the flow and acoustic feedback loop. As a result of this phenomenon, in addition to the fact that the jet mixing is already enhanced by the feedback loop, the mixing enhancement due to the control in the imperfectly-expanded jets is less significant.

show abstract

Section: Introductionmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Active Control on the Flow Structure in a High Reynolds Number Supersonic Jet

Kim¹,

Samimy²

2009

International Journal of Flow Control

Self Cite

View full text Add to dashboard Cite

show abstract

“…The procedure used here is similar to that used by Fourgette et al, 6 Mahadevan et al, 11 Poggie and Smits, 13 Papamoschou and Bunyajitradulya, 14 Smith and Dutton, 16 Murakami and Papamoschou, 17 Thurow et al, 20,22 and Samimy et al 50 This procedure has been used in the past to analyze time-correlated flow visualization data but has not been used on quantitative data of a flow variable such as velocity until recently. 29 Conceptually, the space-time correlation used here is similar to conventional space-time correlations where data are acquired over time at two points ͑i.e., two hot wires or pressure transducers͒; the distance between the probes can then be varied to produce multiple separations. Data in this study, however, are acquired across a plane and separations can be achieved by looking at different regions of each image.…”

Section: Two-dimensional Space-time Correlationsmentioning

confidence: 99%

“…To date, the only convective velocity measurements based on quantitative data, other than those presented here, are the supersonic and high subsonic axisymmetric jet studies of Adelgren et al 23 and Kim et al 29 In these works, the convective velocity of large-scale structures in forced jets were measured using particle image velocimetry ͑PIV͒. The forcing condition allowed for phase locking of the measurements to the flow control actuator, from which an average convective velocity could be determined.…”

Section: Introductionmentioning

confidence: 97%

Issues with measurements of the convective velocity of large-scale structures in the compressible shear layer of a free jet

et al. 2008

Self Cite

View full text Add to dashboard Cite

Experiments were conducted to measure convective velocity of large-scale structures in the shear layer of a Mach 2.0 free jet with a convective Mach number of 0.87 and Reynolds number based on a nozzle diameter of 2.6ϫ 10 6 . Real-time flow visualization and planar Doppler velocimetry ͑PDV͒ measurements along with space-time correlation were used. The results reveal that regardless of the measurement technique employed, whether qualitative flow visualization or quantitative PDV, the method of seeding can have a significant effect on the ability to accurately identify, track, and measure convective velocity of large-scale structures. This is apparent by the relatively large spread in convective velocity results obtained in the same jet by using various methods of seeding and qualitative and quantitative visualization. Convective velocity measurements made under the best seeding conditions available with PDV indicate a convective velocity of structures that is close to the value predicted by theory up to the convective Mach number of 0.87 used in the current work. This is in contrast to previously reported convective velocity measurements ͑including those of the present authors͒ that indicated a deviation from the theoretically predicted value but were based on measurements made under less than ideal seeding conditions.

show abstract

Detachment and attachment of an axisymmetric non-reactive jet with turbulent shear layer: Control by plasma actuator

Bénard

Braud

Touchard

et al. 2008

Experimental Thermal and Fluid Science

View full text Add to dashboard Cite

Active Control of High Subsonic Jets

Cited by 13 publications

References 10 publications

Effects of Active Control on the Flow Structure in a High Reynolds Number Supersonic Jet

Effects of Active Control on the Flow Structure in a High Reynolds Number Supersonic Jet

Issues with measurements of the convective velocity of large-scale structures in the compressible shear layer of a free jet

Detachment and attachment of an axisymmetric non-reactive jet with turbulent shear layer: Control by plasma actuator

Contact Info

Product

Resources

About