Lorentz Force Effect on a Supersonic Ionized Boundary Layer

Meyer, Rod; Chintala, Naveen; Adamovich, Igor; Bystricky, Bryan; Hicks, Adam; Cundy, Michael; Lempert, Walter R.

doi:10.2514/6.2004-510

Cited by 16 publications

(11 citation statements)

References 5 publications

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“…7 and 8, respectively, demonstrate the presence of a few warm spots near the center plane of the flow ͑at 6 mm͒ or none at all ͑at 8 mm͒. This is again in good agreement with our previous Pitot probe and schlieren measurements, 9,13,14 which both indicate the boundary layer thickness of approximately 6 mm, with maximum thickness near the center plane. Summarizing, the flow visualization results shown in Figs.…”

Section: -3supporting

confidence: 89%

“…The experiments have been conducted at the supersonic nonequilibrium plasma/MHD wind tunnel facility at the Nonequilibrium Thermodynamics Laboratories. 9,[13][14][15] Briefly, this facility generates stable and diffuse supersonic nonequilibrium plasmas flows at M =3-4 in a uniform magnetic field up to B = 2 T, with run durations from tens of seconds to complete steady state.…”

Section: Methodsmentioning

confidence: 99%

“…LDI signal acquisition, averaging, and processing by the signal analyzer requires a steady-state flow run time of several seconds, depending on the number of averages. Typically, good signal to noise is achieved for the acquisition/processing times of 1-2 s. As in our previous work, 9,[13][14][15] in the present MHD boundary layer control experiments, most LDI measurements are performed for both accelerating and decelerating Lorentz force directions. In both of these cases, Lorentz force can be generated by two possible combinations of the transverse B field and the transverse dc electric field directions.…”

Section: -3mentioning

confidence: 95%

“…The above estimates are consistent with successful boundary layer density fluctuation control experiments in both low-speed salt water flows ͑conductivity up to =3 mho/m, B = 0.4 T, L = 0.25 m, u ϱ =1-5 m/s, =1 kg/cm 3 , c f /2ϳ 10 −3 ͒ 12 and in M = 3 boundary layer flows weakly ionized by an rf discharge ͑ ϳ 0.1 mho/ m, u ϱ =500 m/s, B = 1.5 T, L = 0.05 m, P ϳ 10 Torr, c f /2 ϳ 10 −3 ͒. 9,13,14 In particular, recent experiments at Ohio State 9,13,14 detected an MHD effect on the level of density fluctuations in a supersonic boundary layer weakly ionized by a transverse rf discharge. In these experiments, retarding Lorentz force applied to the flow produced a wellreproduced increase of the density fluctuation intensity by up to 10%-20% ͑1-2 dB͒, compared to the accelerating force applied to the same flow.…”

Section: Introductionmentioning

confidence: 99%

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Low-temperature supersonic boundary layer control using repetitively pulsed magnetohydrodynamic forcing

et al. 2005

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The paper presents results of magnetohydrodynamic ͑MHD͒ supersonic boundary layer control experiments using repetitively pulsed, short-pulse duration, high-voltage discharges in M = 3 flows of nitrogen and air in the presence of a magnetic field of B = 1.5 T. We also have conducted boundary layer flow visualization experiments using laser sheet scattering. Flow visualization results show that as the Reynolds number increases, the boundary layer flow becomes much more chaotic, with the spatial scale of temperature fluctuations decreasing. Combined with density fluctuation spectra measurements using laser differential interferometry ͑LDI͒ diagnostics, this behavior suggests that boundary layer transition occurs at stagnation pressures of P 0 ϳ 200-250 Torr. A crossed discharge ͑pulser+ dc sustainer͒ in M = 3 flows of air and nitrogen produced a stable, diffuse, and uniform plasma, with the time-average dc current up to 1.0 A in nitrogen and up to 0.8 A in air. The electrical conductivity and the Hall parameter in these flows are inferred from the current voltage characteristics of the sustainer discharge. LDI measurements detected the MHD effect on the ionized boundary layer density fluctuations at these conditions. Retarding Lorentz force applied to M = 3 nitrogen, air, and N 2-He flows produces an increase of the density fluctuation intensity by up to 2 dB ͑about 25%͒, compared to the accelerating force of the same magnitude. The effect is demonstrated for two possible combinations of the magnetic field and current directions producing the same Lorentz force direction ͑both for accelerating and retarding force͒.

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Section: -3supporting

confidence: 89%

Section: Methodsmentioning

confidence: 99%

Section: -3mentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

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Low-temperature supersonic boundary layer control using repetitively pulsed magnetohydrodynamic forcing

et al. 2005

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“…Plasma actuators are currently considered to be a promising means of flow control. [2][3][4][5][6][7][8][9] A number of different plasma generation methods have been considered for flow control schemes, including DC glow discharges, RF glow discharges, and dielectric barrier discharges, and control experiments have been carried out both with and without the presence of an applied magnetic field. Significant control effects have been observed in experiments on both high-speed 7,8 and low-speed flow.…”

Section: Introductionmentioning

confidence: 99%

DC Glow Discharges: A Computational Study for Flow Control Applications

Poggie

2005

36th AIAA Plasmadynamics and Lasers Conference

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A numerical study of glow discharges was carried out in order to evaluate their potential for flow control applications. As part of this project, a three-dimensional computer code has been written to solve, in an implicit, loosely-coupled fashion, the fluid conservation laws, the charged particle continuity equations under the drift-diffusion model, and the Poisson equation for the electric potential. Fully three-dimensional calculations have been carried out for DC discharges in nitrogen, and changes in the flow in the presence a discharge have been demonstrated. In computations of a three-dimensional electrode configuration mounted on a flat plate in a Mach 5 crossflow, the discharge was found to thicken the boundary layer. The resulting compression waves led to increased pressure forces at the plate surface. These changes in flow structure occurred through dissipative heating; the body force term in the fluid momentum equation was negligible. The computations are in qualitative agreement with total temperature measurements made in a similar configuration for air flow. 1 A preliminary investigation of the effect of an applied magnetic field has also been carried out. A computation of a simple discharge between parallel plates showed that an applied axial magnetic field tends to suppress the radial component of the current density.

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