Showing papers on "Supersonic speed published in 2006"

Time evolution and mixing characteristics of hydrogen and ethylene transverse jets in supersonic crossflows

Abstract: We report an experimental investigation that reveals significant differences in the near-flowfield properties of hydrogen and ethylene jets injected into a supersonic crossflow at a similar jet-to-freestream momentum flux ratio. Previously, the momentum flux ratio was found to be the main controlling parameter of the jet’s penetration. Current experiments, however, demonstrate that the transverse penetration of the ethylene jet was altered, penetrating deeper into the freestream than the hydrogen jet even for similar jet-to-freestream momentum flux ratios. Increased penetration depths of ethylene jets were attributed to the significant differences in the development of large-scale coherent structures present in the jet shear layer. In the hydrogen case, the periodically formed eddies persist long distances downstream, while for ethylene injection, these eddies lose their coherence as the jet bends downstream. The large velocity difference between the ethylene jet and the freestream induces enhanced mixing at the jet shear layer as a result of the velocity induced stretching-tilting-tearing mechanism. These new observations became possible by the realization of high velocity and high temperature freestream conditions which could not be achieved in conventional facilities as have been widely used in previous studies. The freestream flow replicates a realistic supersonic combustor environment associated with a hypersonic airbreathing engine flying at Mach 10. The temporal evolution, the penetration, and the convection characteristics of both jets were observed using a fast-framing-rate (up to 100 MHz) camera acquiring eight consecutive schlieren images, while OH planar laser-induced fluorescence was performed to verify the molecular mixing.

Supersonic Cavity Flows and Their Control

Abstract: A detailed experimental study of supersonic, Mach 2, flow over a three-dimensional cavity was conducted using shadowgraph visualization, unsteady surface pressure measurements, and particle image velocimetry. Large-scale structures in the cavity shear layer and visible disturbances inside the cavity were clearly observed. A large recirculation zone and high-speed reverse flow was revealed in the cavity. In addition, supersonic microjets were used at the leading edge to suppress flow unsteadiness within the cavity. With a minimal mass flux (blowing coefficient B c = 0.0015), the activation of microjets led to reductions of up to 20 dB in the amplitudes of cavity tones and of more than 9 dB in the overall sound pressure levels. The microjet injection also modified the cavity mixing layer and resulted in a significant reduction in the flow unsteadiness inside the cavity as revealed by the shadowgraphs and the velocity-field measurements.

Shear wave speed recovery in transient elastography and supersonic imaging using propagating fronts

Abstract: Transient elastography and supersonic imaging are promising new techniques for characterizing the elasticity of soft tissues. Using this method, an 'ultrafast imaging' system (up to 10 000 frames s−1) follows in real time the propagation of a low frequency shear wave. The displacement of the propagating shear wave is measured as a function of time and space. The objective of this paper is to develop and test algorithms whose ultimate product is images of the shear wave speed of tissue mimicking phantoms. The data used in the algorithms are the front of the propagating shear wave. Here, we first develop techniques to find the arrival time surface given the displacement data from a transient elastography experiment. The arrival time surface satisfies the Eikonal equation. We then propose a family of methods, called distance methods, to solve the inverse Eikonal equation: given the arrival times of a propagating wave, find the wave speed. Lastly, we explain why simple inversion schemes for the inverse Eikonal equation lead to large outliers in the wave speed and numerically demonstrate that the new scheme presented here does not have any large outliers. We exhibit two recoveries using these methods: one is with synthetic data; the other is with laboratory data obtained by Mathias Fink's group (the Laboratoire Ondes et Acoustique, ESPCI, Universite Paris VII).

The power spectrum of supersonic turbulence in perseus

Abstract: We test a method of estimating the power spectrum of turbulence in molecular clouds based on the comparison of power spectra of integrated intensity maps and single-velocity-channel maps, suggested by A. Lazarian and D. Pogosyan. We use synthetic 13CO data from non-LTE radiative transfer calculations based on density and velocity fields of a simulation of supersonic hydrodynamic turbulence. We find that the method yields the correct power spectrum with good accuracy. We then apply the method to the Five College Radio Astronomy Observatory 13CO map of the Perseus region, from the COMPLETE Web site. We find a power-law power spectrum with slope β = 1.81 ± 0.10. The values of β as a function of velocity resolution are also confirmed using the lower resolution map of the same region obtained with the AT&T Bell Laboratories antenna. Because of its small uncertainty, this result provides a useful constraint for numerical codes used to simulate molecular cloud turbulence.

Experimental Study on Thermal Protection System by Opposing Jet in Supersonic Flow

Abstract: Introduction C URRENTLY, developments of reusable launch vehicle (RLV) for a low-cost space transportation system are in progress. In the development of RLV, one of the most important problems is the severe aerodynamic heating at the nose and leading edges of the vehicle. In such supersonic and hypersonic flights, prediction of aerodynamic heating and construction of proper thermal protection system are especially important. Heat-resistant tiles and ablators are currently used for thermal protection systems. However, those thermal protection systems are not reusable. In the present study, the method using an opposing jet is proposed for fully reusable thermal protection system of RLV. The method can be considered to have almost the same effect of heat reduction at nose region as the method with mechanical spike.1 The opposing jet works as an aerodynamic spike to move the detached shock wave away from the nose and form a recirculation region, which is quite effective to reduce aerodynamic heating at the nose region. The schematic diagram of supersonic flowfields with opposing jet injected at the nose of a blunt body is shown in Fig. 1. In the flowfield, the opposing jet forms a Mach disk and contact surface with freestream. The jet layer reattaches to the body surface and forms a recirculation region between the nozzle exit and reattachment point of the jet layer. The recompression shock wave is formed near the reattachment point of the jet layer. Many studies on opposing jet flow have been conducted in order to reveal the flow mechanism.2−7 However, most of those studies are related to the stability of flowfield and oscillations of shock waves. Except for Warren,6 not much study has been conducted to reveal the effects of opposing jet on reduction of aerodynamic heating. In the present study, geometric ratio of diameters and Mach number are fixed. The flow stability is determined by the total pressure ratio of freestream to opposing jet. We define the total pressure ratio

Plasma generation using high-power millimeter-wave beam and its application for thrust generation

Abstract: Propagation of an ionization front in the beam channel was observed after plasma was generated using a 170GHz millimeter-wave beam in the atmosphere. The propagation velocity of the ionization front was found to be supersonic when the millimeter-wave power density was greater than 75kWcm−2. The momentum coupling coefficient Cm, a ratio of the propulsive impulse to the input energy, was measured using conical and cylindrical thruster models. A Cm value greater than 350NMW−1 was recorded when the ionization front propagated with supersonic velocity.

Counterflow drag reduction by supersonic jet for a blunt body in hypersonic flow

Abstract: Counterflow drag reduction by supersonic jet for a large angle blunt cone at hypersonic Mach number is investigated in a shock tunnel. The flowfields around the test model in the hypersonic flow with an opposing supersonic jet emanating from the stagnation point of the model are visualized by high speed schlieren technique. The aerodynamic drag force is measured using the accelerometer based force balance system. The experimental measurements show about 30%–45% reduction in drag coefficient for different jet pressures.

Scaling Laws and a Method for Identifying Components of Jet Noise

Abstract: It is well established that there are three principal jet noise components for imperfectly expanded supersonic jets. However, to this date there has been no reliable and practical method for identifying the individual components. First, new scaling laws for the turbulent mixing noise component are developed from a comprehensive experimental database generated by the author. The scaling laws are based on the explicit recognition that a) the variation of the overall sound power level with jet velocity has a weak dependence on jet stagnation temperature ratio; b) the variation of the overall sound pressure level with velocity at every radiation angle is a function of jet stagnation temperature ratio. Therefore, the behavior of the turbulent mixing noise at each radiation angle can be characterized by the two independent parameters: the velocity ratio and the stagnation temperature ratio. These two findings set this study apart from past approaches and form the basis for the methodology developed here. It is demonstrated clearly that there is excellent collapse of the mixing noise spectra over the entire frequency range. Once the normalized or master spectra for the mixing noise are established, it is a trivial matter to subtract these from the total measured spectra to obtain the shock-associated noise. For moderately imperfectly expanded heated supersonic jets, the mixing noise component has the same spectral level as the shock-associated noise, over a wide range of higher frequencies. At the lower radiation angles in the forward quadrant, there is a substantial decrease in the values of the velocity exponents as the stagnation temperature ratio is increased. Proceeding aft, the values start to rise and in the peak sector of noise radiation, the velocity exponent becomes less sensitive to jet stagnation temperature ratio unlike at lower angles, and stays close to the values for the unheated jet.

Plasma-Assisted Combustion of Gaseous Fuel in Supersonic Duct

Abstract: The field of plasma-induced ignition and plasma-assisted combustion in high-speed flow is under consideration. Nonequilibrium, unsteady, and nonuniform modes are analyzed as the most promising in reducing a required extra power. Numerical simulations of uniform, nonequilibrium, continuous, and pulse discharge effect on the premixed hydrogen and ethylene-air mixtures in supersonic flow demonstrate an advantage of such a technique over heating. At the same time, the energetic price occurs rather large to be scheme practical. A reduction of the required power deposition and mixing intensification in nonpremixed flow could be achieved by nonuniform electrical discharges. Experimental results on multielectrode discharge maintenance behind wallstep and in the cavity of supersonic flow are presented. The model test on hydrogen and ethylene ignition is demonstrated at direct fuel injection

Acoustic Pressure Waveforms Measured in High Speed Jet Noise Experiencing Nonlinear Propagation

Abstract: An experimental study has been carried out in a controlled environment in a large anechoic chamber at Boeing to clarify certain features associated with the nonlinear distortion of acoustic waves. The test points were chosen to yield both subsonic and supersonic convective Mach numbers. Both spectral and time-domain analyses have been performed to elucidate nonlinear effects. The spectral analysis indicates that there is agglomeration of energy at the higher frequencies as the propagation distance increases. The time-domain analysis shows strong positive peaks in the pressure signals; the skewness values of the acoustic signals jump from ∼0.05 to ∼0.3, when the convective Mach number is increased from low subsonic values to just above unity. An examination of the Morfey-Howell nonlinear indicator reveals that energy is transferred from the spectral peak to the higher frequencies as a consequence of long-distance propagation. It is established that the convective Mach number is a critical parameter that ma...

Use of High-Speed Microjets for Active Separation Control in Diffusers

Abstract: Inlets to aircraft propulsion systems must supply flow to the compressor with minimal pressure loss, flow distortion, or unsteadiness. Flow separation in internal flows such as inlets and ducts in aircraft propulsion systems and external flows such as over aircraft wings is undesirable because it reduces the overall system performance. An experimental investigation is described that was carried out to study the feasibility of using high-speed microjets, supersonic for most cases, to control boundary-layer separation in an adverse pressure gradient. The geometry used is a simple diverging Stratford ramp equipped with arrays of 400-μm-diam microjets. Measurements include detailed surface flow visualizations, mean surface pressure distributions, and velocity field measurements using particle image velocimetry. The results clearly indicate that by activating these microjets the separated flow regions were eliminated. This led to a significant increase in the momentum of the flow near the surface where the gain in momentum was at least an order of magnitude higher than the momentum injected by the microjets. Given the simplicity of the system and its low mass flow requirements, combined with the benefits achieved by this approach, microjets appear to be promising actuators for efficient separation control for internal and external flow applications.

Using level set based inversion of arrival times to recover shear wave speed in transient elastography and supersonic imaging

Abstract: Transient elastography and supersonic imaging are promising new techniques for characterizing the elasticity of soft tissues. Using this method, an ‘ultrafast imaging’ system (up to 10 000 frames s −1 ) follows in real time the propagation of a low-frequency shear wave. The displacement of the propagating shear wave is measured as a function of time and space. Here we develop a fast level set based algorithm for finding the shear wave speed from the interior positions of the propagating front. We compare the performance of level curve methods developed here and our previously developed (McLaughlin J and Renzi D 2006 Shear wave speed recovery in transient elastography and supersonic imaging using propagating fronts Inverse Problems 22 681–706) distance methods. We give reconstruction examples from synthetic data and from data obtained from a phantom experiment accomplished by Mathias Fink’s group (the Laboratoire Ondes et Acoustique, ESPCI, Universit´ e Paris VII).

Computational Study of Shock Mitigation and Drag Reduction by Pulsed Energy Lines

Abstract: A series of numerical experiments were performed in which energy was deposited ahead of a cone traveling at supersonic/hypersonic speeds. The angle of attack was zero, and the cone half-angles ranged from 15 to 45 deg. The Mach numbers simulated were 2, 4, 6, and 8. The energy was deposited instantaneously along a finite length of the cone axis, ahead of the cone’s bow shock, causing a cylindrical shock wave to push air outward from the line of deposition. The shock wave would sweep the air out from in front of the cone, leaving behind a low-density column/tube of air, through which the cone (vehicle) propagated with significantly reduced drag. The greatest drag reduction observed was 96%. (One-hundred percent drag reduction would result in the complete elimination of drag forces on the cone.) The propulsive gain was consistently positive, meaning that the energy saved as a result of drag reduction was consistently greater than the amount of energy “invested” (i.e., deposited ahead of the vehicle). The highest ratio of energy saved/energy invested was approximately 6500% (a 65-fold “return” on the invested energy). We explored this phenomenon with a high-order-accurate multidomain weighted essentially nonoscillatory finite difference algorithm, using interpolation at subdomain boundaries. This drag-reduction/shock-mitigation technique can be applied locally or globally to reduce the overall drag on a vehicle.

Adaptive Mesh Refinement for Supersonic Molecular Cloud Turbulence

Abstract: We present the results of three-dimensional numerical simulations of supersonic isotropic Euler turbulence with adaptive mesh refinement (AMR) and effective grid resolution up to 10243 zones. Our experiments describe nonmagnetized, driven turbulent flows with an isothermal equation of state. Mesh refinement on shocks and shear is implemented to resolve dynamically important structures and calibrated to match the turbulence statistics obtained from the equivalent uniform-grid simulations. We demonstrate that as soon as the integral and dissipation scales are sufficiently separated, further increasing the resolution does not require mesh refinement all over the computational domain. The volume of finer subgrids in our AMR simulations scales with linear resolution approximately as N-1. Turbulence statistics derived from our AMR simulations and simulations performed on uniform grids agree surprisingly well, even though only a fraction of the volume is covered by AMR subgrids. We show that subdimensional nested "Mach cones" and U-shaped shocklets dominate the dynamics in supersonic turbulent flows. Based on these results, we discuss the fractal dimension of dissipative structures, their signature in the statistical properties of supersonic turbulence, and their role in overall flow dynamics.

Reynolds-averaged Navier-Stokes/large-eddy simulations of supersonic base flow

Abstract: Several zonal and nonzonal hybrid Reynolds-averaged Navier-Stokes/large-eddy simulation approaches have been assessed to handle a high Reynolds number supersonic base flow. The results obtained on 5 and 13.5 x 10 6 points grids are compared to the available experimental data (Herrin, J. L., and Dutton, J. C., "Supersonic Base Flow Experiments in the Near Wake of a Cylindrical Afterbody,"AIAA Journal, Vol.32, No. 77,1994), and the capabilities of these different methodologies to predict supersonic flows are discussed. The highly compressible separated shear layer proved to be a challenging issue for hybrid methods due to an alteration in the instability process (as compared to the incompressible case), leading to three-dimensional coherent structures. Numerous numerical parameters relevant to hybrid methods have been assessed. The incoming boundary layer thickness needs to be properly set, while a weak influence of the subgrid scale model is observed when small-scale structures in the separating mixing layer are resolved. Another finding of the present study is the dramatic influence displayed by the numerical dissipation on the flowfield. Sensitivity to the C DES model constant is observed even with the finest grid, leading to a delay in the generation of instabilities in the shear layer.

Effect of Mach number on the structure of turbulent spots

Abstract: Direct numerical simulations have been performed to study the dynamics of isolated turbulent spots in compressible isothermal-wall boundary layers. Results of a bypass transition scenario at Mach 2, 4 and 6 are presented. At all Mach numbers the evolved spots have a leading-edge overhang, followed by a turbulent core and a calmed region at the rear interface. The spots have an upstream-pointing arrowhead shape when visualized by near-wall slices, but a downstream-pointing arrowhead in slices away from the wall. The lateral spreading of the spot decreases substantially with the Mach number, consistent with a growth mechanism based on the instability of lateral shear layers. Evidence for a supersonic (Mack) mode substructure is found in the Mach 6 case, where coherent spanwise structures are observed under the spot overhang region.

Supersonic rupture of rubber

Abstract: The rupture of rubber differs from conventional fracture. It is supersonic, and the speed is determined by strain levels ahead of the tip rather than total strain energy as for ordinary cracks. Dissipation plays a very important role in allowing the propagation of ruptures, and the back edges of ruptures must toughen as they contract, or the rupture is unstable. This article presents several levels of theoretical description of this phenomenon: first, a numerical procedure capable of incorporating large extensions, dynamics, and bond rupture; second, a simple continuum model that can be solved analytically, and which reproduces several features of elementary shock physics; and third, an analytically solvable discrete model that accurately reproduces numerical and experimental results, and explains the scaling laws that underlie this new failure mode. Rupture speeds compare well with experiments, but opening angles of the rupture are not yet captured well.

On transonic shocks in two-dimensional variable-area ducts for steady euler system ∗

Abstract: This paper concerns transonic shocks in compressible inviscid flow passing a two- dimensional variable-area duct for the complete steady Euler system. The flow is supersonic at the entrance of the duct, whose boundaries are slightly curved. The condition of impenetrability is posed on the boundaries. After crossing a nearly flat shock front, which passes through a fixed point on the boundary of the duct, the flow becomes subsonic. We show that to ensure the stability of such shocks, pressure should not be completely given at the exit: it only should be given with freedom one, that is, containing an unknown constant to be determined by the upstream flow and the profile of the duct. Careful analysis shows that this is due to the requirement of conservation of mass in the duct. We used Lagrangian transformation and characteristic decomposition to write the Euler system as a 2 × 2 system, which is valid for general smooth flows. Due to such a simplification, we can employ the theory of boundary value problems for elliptic equations to discuss well-posedness or ill-posedness of transonic shock problems in variable-area duct for various conditions giving at the exit.

Active and Passive Control of Supersonic Impinging Jets

Abstract: The behavior of supersonic impinging jets is dominated by a feedback loop due to the coupling between the fluid and acoustic fields. This leads to many adverse effects when such flows occur in short takeoff and vertical landing aircraft, such as a significant increase in the noise level, very high unsteady loads on the nearby structures, and an appreciable loss in lifting during hover. In earlier studies, it was demonstrated that by using supersonic microjets one could disrupt the feedback loop that leads to substantial reductions in the aforementioned adverse effects. However, the effectiveness of control was found to be strongly dependent on the ground plane distances and the jet-operating conditions. The effect of various microjet control parameters are investigated in some detail to identify their influence on control efficiency and additional insight is provided on the physical mechanism behind this control method. Parameters studied include microjet angle, microjet pressure, and the use of microtabs instead of microjets. These results indicate that by choosing appropriate control parameters it should be possible to devise a control strategy that produces optimal control for the entire operating range of conditions of the supersonic impinging jet. Moreover, the experimental results provide convincing evidence of the generation of significant streamwise vorticity by the activation microjets. It is postulated that the generation of streamwise vorticity and its evolution in the jet flow might be one of the main physical phenomena responsible for the reduction of flow unsteadiness in impinging jets.

Effect of High-temperature Field on Supersonic Oxygen Jet Behavior

Abstract: In the steelmaking process, the behavior of the top blown oxygen jet is an important factor for controlling BOF or EAF operation. Because the temperature in the BOF is very high, jet behavior is still not fully understood. In this study, supersonic oxygen jet behavior in a high-temperature field was investigated by measuring the velocity and temperature of the oxygen jet in a heated furnace, and the results were compared with a jet model proposed by previous researchers. The results showed that velocity attenuation of the jet was restrained and the potential core length was extended in a high-temperature field. Under these experimental conditions, the results were in good agreement with the jet model using Pr=0.715 and Sc=0.708 proposed by Kleinstein. Supersonic jet behavior for SCOPE-JET nozzle, which can be applied in EAF operation to obtain high-energy efficiency, was also investigated. SCOPE-JET had a long potential core and attenuation of the jet in the axial direction was extremely restrained. It was shown to be possible to obtain the jet behavior of SCOPE-JET nozzle using the jet model with the adiabatic flame temperature as the ambient temperature and appropriate temperature attenuation behavior in the axial direction.

Application of aeroelastic modes on nonlinear supersonic panel flutter at elevated temperatures

Abstract: This paper shows that the use of aeroelastic modes, instead of the traditional in vacuo natural modes, can reduce drastically the number of coupled nonlinear modal equations for the large amplitude nonlinear panel flutter analysis at an arbitrary yawed supersonic flow angle and elevated temperatures. All four types of panel behavior can be predicted and they are flat and stable, aerothermally buckled but dynamically stable, limit cycle oscillations, and chaos.

All-Speed Time-Accurate Underwater Projectile Calculations Using a Preconditioning Algorithm

Abstract: An algorithm based on the combination of time-derivative preconditioning strategies with low-diffusion upwinding methods is developed and applied to multiphase, compressible flows characteristic of underwater projectile motion Multiphase compressible flows are assumed to be in kinematic and thermodynamic equilibrium and are modeled using a homogeneous mixture formulation Compressibility effects in liquid-phase water are modeled using a temperature-adjusted Tait equation, and gaseous phases (water vapor and air) are treated as an ideal gas The algorithm is applied to subsonic and supersonic projectiles in water general multiphase shock tubes, and a high-speed water entry problem Low-speed solutions are presented and compared to experimental results for validation Solutions for high-subsonic and transonic projectile flows are compared to experimental imaging results and theoretical results Results are also presented for several multiphase shock tube calculations Finally, calculations are presented for a high-speed axisymmetric supercavitating projectile during the important water entry phase of flight

Accelerated hygrothermal cyclical tests for carbon/epoxy laminates

Abstract: The paper deals with the design of reasonable accelerated test conditions to assess polymer matrix composite durability when it is subjected to supersonic flight-cycles. The study is closely linked to novel application of carbon fibre polymer matrix composites in supersonic aircraft primary structures, leading to substantial weight saving and stiffness improvement. A supersonic flight can result in surface temperatures close to 130 °C, inducing severe thermal gradients and drying which are quite new for this type of materials, now used in primary structures of subsonic jets operating at low subsonic flight-temperatures. Therefore, the particular effect of the drying on the long-term behaviour of composites should be investigated. Numerical simulations based on Fick's law confirm that the supersonic flight-cycles induce a material drying on the long-term and a significant moisture uptake occurs during the aircraft maintenance periods. Then, particular accelerated cycles are proposed to approach the effect of the drying and moisture uptake during service life. First experiments showed that the long-term hygrothermal fatigue can induce significant changes in the material properties and a drop in the glass transition temperature of about 20 °C.

Supersonic Inlet Shaping for Dramatic Reductions in Drag and Sonic Boom Strength

Abstract: An alternate approach has been identified for defining supersonic inlet compression surface geometry, the use of which increases the design latitude for lofting the inlet cowling region while permitting control over other key inlet design variables. Through this approach, a novel inlet design space is analytically shown to significantly improve supersonic aircraft performance and reduce sonic boom overpressure compared to high-speed inlets designed using traditional methods and constraints. Installed specific fuel consumption improvements of up to 11 percent and sonic boom overpressure reductions of 16 percent were observed for a podded axisymmetric external compression inlet designed for Mach 1.8 cruise. A theoretical discussion and physical description of the alternate inlet design concept is provided along with a summary of the analysis methodology used to judge the concept’s merit against conventional configurations. Inlet performance metrics, presented as a function of key design variables, are compared; and CFD solutions of the compression and diffusion flow environment are included. Drag characteristics at off-design Mach number are also presented. An extended range, low sonic boom vehicle concept is used as an aircraft study platform for which installed CFD-based drag and sonic boom comparisons are made.

Experimental Characterization of a Supersonic Flow Control Actuator

Abstract: Computational and experimental techniques are being used to investigate the operating characteristics of a promising cavity device for high-speed flow control called the SparkJet actuator. This actuator, which produces a synthetic jet with high exhaust velocities, holds the promise of manipulating supersonic boundary layers without active mechanical components. This paper focuses on the experimental characterization of a newly-redesigned SparkJet. Numerical parametric studies of the previous design characterized the performance attributes of the device as a function of orifice size, chamber volume, and energy deposited. Current experimental efforts to assess the new mm-scale actuator design include the application of high-resolution particle image velocimetry to quantify quiescent air operation, and the use of a miniaturized thrust stand to measure SparkJet impulse bit data and to determine an optimal duty cycle. Both data sets will also be used to calibrate the computations and to determine a confidence level in the prediction capability.

Snowplow Surface Discharge in Magnetic Field for High Speed Boundary Layer Control

Abstract: The performance of air breathing supersonic and hypersonic vehicles is strongly affected by the boundary layer that forms along the surface of the inlet. At offdesign operating conditions, a shockwave intersecting the boundary layer can cause the flow to separate which may lead to a drastic reduction in vehicle performance. The work presented in this paper explores a possible way to use magnetically driven surface contracted plasma column to accelerate the flow near the surface. The velocity of the plasma column in a Mach 2.8 in-draft tunnel was investigated at different magnetic field strengths (up to 2.0 Tesla) and was recorded using a high-speed camera. The discharge was observed to travel several times faster than the neutral flow and the velocity was seen to increase with the increasing magnetic field. Pitot probe measurements indicated that magnetically accelerated plasma column affected the flow near the wall and may have the potential of providing a method for flow boundary layer acceleration and flow control.