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Showing 1 to 20 of 28 for “"normal shock"”.
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Normal Shock Wave-Boundary Layer Interactions in Transonic Intakes at Incidence
… flow might accelerate to supersonic speeds. A shock wave might appear and impinge on the incoming boundary layer. Flow separation may result from this interaction, leading to severe flow distortion. In order to maximise fuel efficiency by reducing aerodynamic drag, slimmer nacelle designs are …
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Molecular dynamics modeling of normal shock waves in monatomic and polyatomic gas mixtures.
… are performed to study the structure of normal shock waves in dilute Nitrogen and mixtures of Helium-Argon and Helium-Xenon. The use of realistic MD simulations of normal shock waves promises to provide a more detailed solution than can be provided experimentally, providing a means to …
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The effects of micro-vortex generators on normal shock wave/boundary layer interactions
Shock wave/boundary-layer interactions (SWBLIs) are complex flow phenomena that are important in the design and performance of internal supersonic and transonic flow fields such as engine inlets. This investigation was undertaken to study the effects of passive flow control devices on normal shock …
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Post-Shock Thermochemistry in Hypervelocity Carbon Dioxide and Air Flow
… relaxation region behind a stationary shock wave in a hypervelocity air Mach 7.42 freestream. The normal shock wave is established through a Mach reflection from an opposing wedge arrangement. Schlieren images confirm that the shock configuration is steady and the location is …
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Experimental Investigation of the Effects of a Passing Shock on Compressor Stator Flow
… with an inlet Mach number of 0.65. The bow shock from the downstream rotor was simulated by a single moving normal shock generated with a shock tube. First, steady pressure data were gathered to ensure that the stator cascade operated properly without the presence of the shock. Next, the …
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An investigation of highly underexpanded exhaust jets impinging normal to a curved surface
… exhaust jets impinging in a direction normal to a curved surface was conducted in the NASA-Langley Research Center 55-foot vacuum cylinder. The investigation included measurements of impingement pressures and measurements of various normal shock characteristics. Variables of the …
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Numerical and experimental investigation of VG flow control for a low-boom inlet
The application of vortex generators (VGs) for shock/boundary layer interaction flow control in a novel external compression, axisymmetric, low-boom concept inlet was studied using numerical and experimental methods. The low-boom inlet design features a zero-angle cowl and relaxed isentropic …
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First steps in development of a translational non equilibrium model using maximum entropy principle
… setting . The problem studied is that of a normal shock occurring in a monoatomic gas. The various assumptions, validation tools used and problems associated with model development are elaborated.
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Experimental Measurements of Pressure, Temperature, and Density Using High-Resolution N(2) Coherent Anti-Stokes Raman Scattering
… as the conditions immediately downstream of this normal shock. Further downstream, both the CARS and CFD temperature distributions corroborate the existence of concentric inner and outer shear layers. The former evolves from a slip line that separates the subsonic inner jet fluid from the …
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Assessment of high-fidelity collision models in the direct simulation Monte Carlo method
… atomic oxygen transport properties, and normal shock waves have therefore been investigated. Recommendations for variable soft sphere and Lennard-Jones model parameters are made based on a critical review of recent <em>ab-initio</em> calculations and experimental measurements of transport …
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Post-shock thermochemistry in hypervelocity CO2 and air flow
… dissociation in comparison to reflected shock tunnels. This simplifies the comparison with computational result as freestream dissociation and considerable thermochemical excitation can be neglected. Shock shapes of the MSL aeroshell and spherical geometries are compared with numerical …
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Deterministic numerical simulation of the Boltzmann and kinetic model equations for classical and quantum dilute gases
… Sever classical benchmarking problems (the normal shock wave, and the planar Fourier/Couette/force-driven Poiseuille flows) are investigated. For normal shock waves, our numerical results are compared with the finite-difference solution of the Boltzmann equation for hard sphere molecules, …
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A Simple Computational Model for Particle Resuspension Behind a Normal Moving Shock
… of particle resuspension from a surface due to shock passage and subsequent piston flow presents a means to analyze the post-shock conditions of an environment, such as after a dirty' bomb is detonated. This computational model is based on the 'Rock'n Roll' models of particle detachment by …
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Observation and Measurement of the Growth of the Primary Instabilities of the Richtmyer-Meshkov Instability and Observation of Secondary Instabilities
… of the Richtmyer-Meshkov (RM) instability in a shock-accelerated, initially cylindrical gas column; that is, the counter-rotating vortex pair and the central spike; and the observation of secondary instabilities within the primary instability. The formation of the instabilities is the result of …
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The dynamics of multi-dimensional detonation
… when the radius of curvature of the detonation shock is large compared with the one-dimensional steady Chapman-Jouguet (CJ) detonation reaction-zone thickness. The analysis considers additional time-dependence in the slowly-varying reaction zone than that considered in previous works. The …
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A study of compressibility effects on laminar, unsteady flow past a two-dimensional bluff body
… supersonic. It has been observed that embedded shock waves form in the vortex formation region even when the inflow is subsonic. The presence of normal shock waves which bound the near wake has also been observed. At supersonic speeds, the wake structure changed significantly. The vortex roll up …
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Active control of supersonic boundary layers using electric arc plasma actuators
… the LAFPA’s effects on the stability of a normal shock. It was determined that actuation had virtually no effect on either the mean or standard deviation of the position of the normal shock, for either of the boundary layer configurations and regardless of stagnationto- exit pressure ratio. …
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Oblique Shock Wave Effects on Impulsively Accelerated Heavy Gas Column
… to elucidate the fundamental physics of shock-induced mixing for a simple three-dimensional interface. The interface studied consists of a gravity stabilized SF6-based heavy gas jet that produced a circular column with a diffuse interface into the surrounding air. The effects of density …
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Experimental investigation of normal, sonic injection through a wedge-shaped nozzle into supersonic flow
An experimental evaluation of normal, sonic, helium injection from a wedgeshaped nozzle and a circular nozzle into a Mach 3 free stream with a total pressure of 6.5 atm and a total temperature of 294 K was conducted. The expansion ratio and the mass rate of flow of both nozzles were matched in …
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Supersonic Combustion of Solid Fuels
… changes in density of the flow field and finds a normal shock in the constant area section. CH* chemiluminescence imaging provides novel observations of the concentrated areas of combustion along the fuel grain wall by highlighting the heat release from combustion. A high intensity of CH* radicals …
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