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184
Jun 21, 2010
06/10
by
Aller, L. H.; Bowen, I. S.; Kaler, J. B
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No Abstract Available
Topics: ALCOHOLS, CYCLOHEXANE, POLYMORPHISM, CALORIMETERS, DIELECTRICS, NUCLEATION, PHASE TRANSFORMATIONS,...
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Jun 1, 2011
06/11
by
Alkemper, Jens; Mendoza, Roberto; Kammer, Dimitris; Voorhees, Peter W
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Dendrite coarsening is a common phenomenon in casting processes. From the time dendrites are formed until the inter-dendritic liquid is completely solidified dendrites are changing shape driven by variations in interfacial curvature along the dendrite and resulting in a reduction of total interfacial area. During this process the typical length-scale of the dendrite can change by orders of magnitude and the final microstructure is in large part determined by the coarsening parameters. Dendrite...
Topics: COMBINATORIAL ANALYSIS, ALGORITHMS, PHASE TRANSFORMATIONS, CRITICAL POINT, TRANSITION POINTS,...
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362
May 31, 2011
05/11
by
Oefelein, Joseph C
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This paper highlights results from the first of a series of hierarchical simulations aimed at assessing the modeling requirements for application of the large eddy simulation technique to cryogenic injection and combustion processes in liquid rocket engines. The focus is on liquid-oxygen-hydrogen coaxial injectors at a condition where the liquid-oxygen is injected at a subcritical temperature into a supercritical environment. For this situation a diffusion dominated mode of combustion occurs in...
Topics: UNSTEADY FLOW, TRANSITION POINTS, AERODYNAMIC STALLING, COMPUTATIONAL FLUID DYNAMICS, NAVIER-STOKES...
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194
Jun 17, 2010
06/10
by
Grenier, G.; Persoz, B
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Determination of glass transition point temperature based on variation of pendular hardness
Topics: DUNES, TRANSITION POINT, GLASS, GLASS TRANSITION TEMPERATURE, HARDNESS, PENDULUMS, PLASTICS,...
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217
Jul 11, 2010
07/10
by
Coles, W. A.; Rickett, B. J
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Interplanetary scintillation observations from 1971-1975 show that the average solar wind speed increases away from the solar equator, with a mean gradient of 2.1 km/s per degree. These results are compared with spacecraft observations over the or - 7 deg attainable in the ecliptic and with those deduced from comet tails. The role of temporal variations, especially those caused by latitude dependent solar wind streams, is emphasized, and this points to the need for extensive ecliptic and...
Topics: ATMOSPHERIC EFFECTS, TRANSITION POINTS, POLYIMIDES, POLYMERIC FILMS, TEMPERATURE EFFECTS, WEAR,...
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215
Jun 21, 2010
06/10
by
Sutliff, J. D
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Method for deployment of flexible wing glider from space vehicle with minimum impact and loading
Topics: NUCLEAR SCATTERING, SPACE-TIME FUNCTIONS, THREE BODY PROBLEM, TRANSITION POINTS, ELASTIC...
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343
Jun 18, 2010
06/10
by
Garlick, R. G
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Ductile-brittle transition behavior of zone refined tungsten single crystals as function of orientation
Topics: BRITTLENESS, DUCTILITY, SINGLE CRYSTAL, TUNGSTEN, ZONE REFINING, DUCTILITY, METAL CRYSTALS,...
A summary of the data acquired concerning line identification and lifetime measurements in the xuv and soft X-ray regions for a variety of both resonance transitions and forbidden transitions in ions of astrophysical interest is provided. Particular attention is called to a few papers which appeared in the Astrophysical Journal. These are of special relevance to specific astrophysical data needs. The many experiments completed in areas related to but somewhat outside the confines of the project...
Topics: NASA Technical Reports Server (NTRS), LINE SPECTRA, ULTRAVIOLET RADIATION, X RAYS, HALF LIFE,...
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179
May 23, 2011
05/11
by
deGroot, Wim A.; McGuire, Thomas J.; Schneider, Steven J
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The flow field inside a 110 N gaseous hydrogen/oxygen thruster was investigated using an optically accessible, two-dimensional laboratory test model installed in a high altitude chamber. The injector for this study produced an oxidizer-rich core flow, which was designed to fully mix and react inside a fuel-film sleeve insert before emerging into the main chamber section, where a substantial fuel film cooling layer was added to protect the chamber wall. Techniques used to investigate the flow...
Topics: LIQUID BRIDGES, TRANSITION POINTS, VIBRATION, STABILITY, FORCE DISTRIBUTION, OPTICAL MEASUREMENT,...
A blended wing-body aircraft includes a central body, a wing, and a transition section which interconnects the body and the wing on each side of the aircraft. The two transition sections are identical, and each has a variable chord length and thickness which varies in proportion to the chord length. This enables the transition section to connect the thin wing to the thicker body. Each transition section has a negative sweep angle.
Topics: NASA Technical Reports Server (NTRS), BLENDED-WING-BODY CONFIGURATIONS, WINGS, AIRCRAFT DESIGN,...
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281
Jun 20, 2010
06/10
by
Galitskiy, R. M.; Larkin, A. I.; Vaks, V. G
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Microscopical approach to thermodynamics and phase transitions in ferroelectrics
Topics: FERROELECTRICITY, RELAXATION (MECHANICS), TRANSITION POINTS, VIBRATIONAL SPECTRA, PHASE...
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295
Jul 12, 2010
07/10
by
Chaussee, D. S.; Mcmillan, O. J
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A computer code is described which may be used to calculate the steady, supersonic, three-dimensional, inviscid flow over blunt bodies. The theoretical and numerical formulation of the problem is given (shock-capturing, downstream marching), including exposition of the boundary and initial conditions. The overall flow logic of the program, its usage, accuracy, and limitations are discussed.
Topics: AERODYNAMIC DRAG, TRANSITION POINTS, BOUNDARY LAYER TRANSITION, COEFFICIENT OF FRICTION, FLOW...
Friction and wear experiments conducted on polyimide films bonded to 440C stainless steel disks indicated that a wear transition (from high wear to low wear) accompanied a friction transition (from high friction to low friction). In dry argon or dry air (less than 20 ppm H2O), the transition was found to occur at 40 plus or minus 10 C; when H20 was present in air (10,000 ppm H2O), the transition was found to be elevated to a temperature between 100 and 200 C. Wear rate calculations made at 25,...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC EFFECTS, POLYIMIDES, POLYMERIC FILMS, TEMPERATURE...
203
203
May 27, 2011
05/11
by
Lansing, Donald L
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A theory for the supersonic flow about bodies in uniform flight in a homogeneous medium is reviewed and an integral which expresses the effect of body shape upon the flow parameters in the far field is reduced to a form which may be readily evaluated for arbitrary body shapes. This expression is then used to investigate the effect of nose angle, fineness ratio, and location of maximum body cross section upon the far-field pressure jump across the bow-shock of slender bodies. Curves are...
Topics: AERODYNAMICS, NAVIER-STOKES EQUATION, MACH NUMBER, EXHAUST SYSTEMS, COEFFICIENTS, PRESSURE,...
The partial structure factors of classical simple liquid mixtures near phase separation are dicussed. The theory is developed for particles interacting through pair potentials, and is thus appropriate both to insulating fluids, and also to metallic systems if these may be described by an effective ion-ion pair interaction. The motivation arose from consideration of metallic liquid mixtures, in which resistive anomalies have been observed near phase separation. A mean field theory correction...
Topics: NASA Technical Reports Server (NTRS), BINARY ALLOYS, LIQUID METALS, PERTURBATION THEORY, PHASE...
During this six month period of the Simulation Studies for Surfaces and Materials Strength program investigations were carried out in two general areas: (1) Energy barriers and structural transitions between isomers of small Al clusters were investigated. In this study an empirical potential function which was parametrized based on accurate first principle results was employed; (2) A comparative study was conducted to investigate the applicability of most commonly employed model potential...
Topics: NASA Technical Reports Server (NTRS), ALUMINUM, CLUSTER ANALYSIS, MECHANICAL PROPERTIES,...
A comprehensive data base is given for the low speed aerodynamic characteristics of the NACA 0012 airfoil section. The Langley low-turbulence pressure tunnel is the facility used to obtain the data. Included in the report are the effects of Mach number and Reynolds number and transition fixing on the aerodynamic characteristics. Presented are also comparisons of some of the results with previously published data and with theoretical estimates. The Mach number varied from 0.05 to 0.36. The...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CHARACTERISTICS, AIRFOILS, LOW SPEED WIND...
Recent evidence has shown that the NASA/Lewis Ice Accretion Model, LEWICE, does not predict accurate ice shapes for certain glaze ice conditions. This paper will present the methodology used to make a first attempt at improving the ice accretion prediction in these regimes. Importance is given to the correlations for heat transfer coefficient and ice density, as well as runback flow, selection of the transition point, flow field resolution, and droplet trajectory models. Further improvements...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT ICING, COMPUTER PROGRAMS, HEAT TRANSFER...
Our knowledge of late-stage hypersonic boundary layer transition is very limited, since most theoretical and experimental work has concentrated on the linear disturbance amplification regime. Although experiments show linear higher harmonics beginning at approximately one-half the transition Reynolds number, there is no experimental evidence for subharmonics, in contrast to subsonic boundary layer transition. A practical definition of transition is the location where mean surface heat transfer...
Topics: NASA Technical Reports Server (NTRS), HYPERSONIC BOUNDARY LAYER, BOUNDARY LAYER TRANSITION, LAMINAR...
The behavior of dense liquids near the solidification point under the influence of magnetic fields or near-zero gravity conditions were analyzed within the framework of existing liquid state models and classical field theory. The dynamic body forces which are an effect of the magnetic field on liquids are discussed. It is concluded that both magnetic fields and low gravity conditions produce an increase in the diffusion coefficient which result in an increased growth rate of crystals, and time...
Topics: NASA Technical Reports Server (NTRS), MAGNETIC EFFECTS, SPACE MANUFACTURING, TRANSITION POINTS,...
The ProSEDS conductive tether design incorporates two distinct types of tethers from a plasma interaction viewpoint. The 200 m closest to the Delta II spacecraft is insulated from the plasma, and the remaining 4800 m is semi-bare. This latter portion is considered semi-bare because a conductive coating, which is designed to collect electrons from the plasma, was applied to the wires to regulate the overall tether temperature. Because the tether has both insulating and conductive tether...
Topics: NASA Technical Reports Server (NTRS), PLASMA INTERACTIONS, TETHERING, INSULATION, SPACE PLASMAS,...
It was shown that, in the presence of the steep temperature gradients characteristic of EUV models of the solar transition region, the electron and proton velocity distribution functions are non-Maxwellian and are characterized by high energy tails. The magnitude of these tails are estimated for a model of the transition region and the heat flux is calculated at a maximum of 30 percent greater than predicted by collision-dominated theory.
Topics: NASA Technical Reports Server (NTRS), ELECTRONS, FAR ULTRAVIOLET RADIATION, SOLAR SPECTRA,...
Twenty-three vertical profiles of the bio-optical properties of the ocean were made during a research cruise on the R/V Thomas Washington, June 24 to July 21, 1988, as part of the Coastal Transition Zone Program off Point Arena, California. A summary is given, to provide investigators with an overview of the data collected. The entire data set is available in digital form for interested researchers.
Topics: NASA Technical Reports Server (NTRS), ATLANTIC OCEAN, CHLOROPHYLLS, COASTS, OCEANOGRAPHY, OPTICAL...
A liquid bridge is a volume of liquid held between two or more solid supports. In the case of small disk supports with a sharp edge, the contact line between the bridge and the support disk will be anchored along the edge of the disk. For these cases the solid presents a geometrical singularity and the contact angle is indeterminate within a given range. This dissertation presents research conducted on liquid bridges with anchored contact lines. The three major topics covered are: determining...
Topics: NASA Technical Reports Server (NTRS), LIQUID BRIDGES, FORCE DISTRIBUTION, OPTICAL MEASUREMENT,...
Twenty vertical profiles of the bio-optical properties of the ocean were made during a research cruise on the R/V Point Sur, June 15 to 28, 1987, as part of the Coastal Transition Zone Program off Point Arena, California. Extracted chlorophyll values were also measured at some stations to provide calibration data for the in situ fluorometer. This summary provides investigators with an overview of the data collected. The entire data set is available in digital form.
Topics: NASA Technical Reports Server (NTRS), ATLANTIC OCEAN, CHLOROPHYLLS, COASTS, OCEANOGRAPHY, OPTICAL...
Finite element analyses of flat, reduced gage section tensile specimens with various transition region contours were performed. Within dimensional constraints, such as maximum length, tab region width, gage width, gage length, and minimum tab length, a transition contour radius of 41.9 cm produced the lowest stress values in the specimen transition region. The stresses in the transition region were not sensitive to specimen material properties. The stresses in the tab region were sensitive to...
Topics: NASA Technical Reports Server (NTRS), COMPOSITE MATERIALS, FLATNESS, SPECIMEN GEOMETRY, STRESS...
The importance of transition modeling in the computation of compressible, unsteady separated flows is discussed. The study showed that it is critical to predict the experimentally attained transition point properly in order to obtain good agreement with data it the same Mach number and Reynolds number.
Topics: NASA Technical Reports Server (NTRS), UNSTEADY FLOW, TRANSITION POINTS, AERODYNAMIC STALLING,...
Research into quantum algorithms for NP-complete problems has rekindled interest in the detailed study a broad class of combinatorial problems. A recent paper applied the quantum adiabatic evolution algorithm to the Exact Cover problem for 3-sets (EC3), and provided an empirical evidence that the algorithm was polynomial. In this paper we provide a detailed study of the characteristics of the exact cover problem. We present the annealing approximation applied to EC3, which gives an...
Topics: NASA Technical Reports Server (NTRS), COMBINATORIAL ANALYSIS, ALGORITHMS, PHASE TRANSFORMATIONS,...
The motivation and potential for performing very high resolution measurements of the heat capacity singularity at the lambda point of helium in microgravity conditions was briefly discussed. It is clear that tests extending deep into the asymptotic region can be performed, where the theoretical predictions take on their simplest form. This advantageous situation should lead to a major improvement in the understanding of the range of applicability of current theoretical ideas in this field. The...
Topics: NASA Technical Reports Server (NTRS), MATHEMATICAL MODELS, MICROGRAVITY, SPECIFIC HEAT, STATISTICAL...
The high temperature oxidation of silicon carbide occurs in either a passive or active mode, depending on temperature and oxygen potential. Passive oxidation forms a protective oxide film which limits attack of the SiC:SiC(s) + 3/2 O2(g) = SiO2(s) + CO(g.) Active oxidation forms a volatile oxide and leads to extensive attack of the SiC: SiC(s) + O2(g) = SiO(g) + CO(g). The transition points and rates of active oxidation are a major issue. Previous studies are reviewed and the leading theories...
Topics: NASA Technical Reports Server (NTRS), SILICON CARBIDES, MICROSTRUCTURE, DECOMPOSITION, HIGH...
R&D Report 1969-26 : Pulse-code modulation for high-quality sound-signal distribution: A simulation of instantaenous companding A.H. Jones This report describes a series of subjective tests made to discover whether instantaneous companding could profitably be applied to a pulse-code-modulation system designed for high quality sound signals. It was concluded that the benefits derived from this type of companding would be too small to justify the additional instrumental complexity involved.
Topics: signal, quantizing, instantaneous, digits, levels, curves, transition, companding, simulation,...
Methods for transition detection were studied. The very high test and model costs necessitate testing of any new configuration over a range of Reynolds numbers for correlation with data obtained in conventional tunnels. The Reynolds number variations will be carried out at constant dynamic pressure, i.e., constant aeroelastic condition, by varying test temperature. Boundary layer transition cannot be expected to occur at the full scale location at significantly less than full-scale Reynolds...
Topics: NASA Technical Reports Server (NTRS), CRYOGENIC WIND TUNNELS, FLOW VISUALIZATION, REYNOLDS NUMBER,...
A method is developed for determining the laminar-to-turbulent transition point in a boundary layer. The method involves the measurement of pressure on the surface of the body and the computation of pressure fluctuations. This method of determining the transition point is suitable when visualization methods cannot be used.
Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYERS, FLUID FLOW, LAMINAR FLOW, PRESSURE...
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413
Jul 26, 2010
07/10
by
Richwine, David M.; Curry, Robert E.; Tracy, Gene V
texts
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A smoke generator system was developed for in-flight vortex flow studies on the F-18 high alpha research vehicle (HARV). The development process included conceptual design, a survey of existing systems, component testing, detailed design, fabrication, and functional flight testing. Housed in the forebody of the aircraft, the final system consists of multiple pyrotechnic smoke cartridges which can be fired simultaneously or in sequence. The smoke produced is ducted to desired locations on the...
Topics: BOUNDARY LAYER TRANSITION, SURFACE PROPERTIES, SURFACE ROUGHNESS EFFECTS, WIND TUNNEL TESTS,...
The effect of rotational speed (centrifugal force) on gear crack propagation direction was explored. Gears were analyzed using finite element analysis and linear elastic fracture mechanics. The analysis was validated with crack propagation experiments performed in a spur gear fatigue rig. The effects of speed, rim thickness, and initial crack location on gear crack propagation direction were investigated. Crack paths from the finite element method correlated well with those deduced from gear...
Topics: NASA Technical Reports Server (NTRS), LOW SPEED, CENTRIFUGAL FORCE, CRACK PROPAGATION, GEARS,...
The mechanism of fluid resistance within the limit of the square law is presented. It was concluded that the investigations should be extended and completed in two directions, namely: by an investigation of stable vortex configurations in space, and by considering the perfect fluid as the limiting case of a viscous fluid and then limiting the law of vortex of formation with the condition that only those fluid particles which were in contact with the surface of the body can receive rotation.
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC DRAG, BOUNDARY LAYER TRANSITION, COEFFICIENT OF...
It is proposed to investigate the effect of sudden change in the slope of the surface on the stability and transition onset point in supersonic and hypersonic boundary layers. Since we can not use the linear stability theory in flows where there are discontinuities we have to solve the full Navier-Stokes equations to determine the amplification of the disturbances across the oblique shock which exists at the corner. We will use the Navier-Stokes code which was developed by Dr. Harold Atkins in...
Topics: NASA Technical Reports Server (NTRS), TRANSITION POINTS, SUPERSONIC FLOW, NAVIER-STOKES EQUATION,...
A two-dimensional laminar flow airfoil (NLF-0414) was subjected to high-intensity sound (pure tones and white noise) over a frequency range of 2 to 5 kHz, while immersed in a flow of 240 ft/sec (Rn of 3 million) in a quiet flow facility. Using a wake-rake, wake dynamic pressures were determined and the deficit in momentum was used to calculate a two dimensional drag coefficient. Significant increases in drag were observed when the airfoil was subjected to the high intensity sound at critical...
Topics: NASA Technical Reports Server (NTRS), ACOUSTICS, AIRFOIL PROFILES, DRAG, LAMINAR FLOW, DYNAMIC...
An investigation of the interaction of a laminar boundary layer and surface static-pressure orifices was conducted on a natural laminar flow airfoil. The effects of both favorable and adverse pressure gradients were studied at Reynolds numbers based on airfoil chord from approximately 500,000 to 6,000,000 with Mach number varying accordingly from about 0.03 to 0.42. The smaller the diameter of the orifice, the less likely it will cause premature transition. Locating the orifices in a chord-wise...
Topics: NASA Technical Reports Server (NTRS), AIRFOILS, BOUNDARY LAYER TRANSITION, LAMINAR FLOW, PRESSURE...
178
178
Jul 26, 2010
07/10
by
Connor, Andrew B.; Ludi, Leroy H
texts
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No Abstract Available
Topics: BOUNDARY LAYER CONTROL, WIND TUNNEL TESTS, SCHLIEREN PHOTOGRAPHY, SUPERSONIC SPEED, WIND TUNNEL...
We have developed a code where the nonlinear terms are treated implicitly. The equations are discretized using the two-point fourth order compact scheme in the y-direction and the backward Euler method in the x-direction. We investigated the transition process in a Blasius boundary layer due to fundamental type breakdown. With 8 modes in the w and 3 planes, we could compute the evolution of disturbances up to Re(x)=910, which is well into the strongly nonlinear region. The transition onset...
Topics: NASA Technical Reports Server (NTRS), INCOMPRESSIBLE BOUNDARY LAYER, TURBULENCE, TURBULENT BOUNDARY...
This work focuses on the properties of sheared granular materials near the jamming transition. The project currently involves two aspects. The first of these is an experiment that is a prototype for a planned ISS (International Space Station) flight. The second is discrete element simulations (DES) that can give insight into the behavior one might expect in a reduced-g environment. The experimental arrangement consists of an annular channel that contains the granular material. One surface, say...
Topics: NASA Technical Reports Server (NTRS), GRANULAR MATERIALS, SIMULATION, SHEAR PROPERTIES,...
The effects of boundary layer flows along the walls of wind tunnels were studied to validate the transfer of two dimensional calculations to three dimensional transonic flowfield calculations. Results from trials in various wind tunnels were examind to determine the effects of the wall boundary flow on the control surfaces of an airfoil. Models sliding along a groove in the wall of a channel at sub- and transonic speeds were examined, with the finding that with either nonuniformities in the...
Topics: NASA Technical Reports Server (NTRS), AIRFOIL PROFILES, FLOW DISTRIBUTION, THREE DIMENSIONAL...
The RNG-based algebraic turbulence model, with a new method of solving the cubic equation and applying new length scales, is introduced. An analysis is made of the RNG length scale which was previously reported and the resulting eddy viscosity is compared with those from other algebraic turbulence models. Subsequently, a new length scale is introduced which actually uses the two previous RNG length scales in a systematic way to improve the model performance. The performance of the present RNG...
Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER FLOW, BOUNDARY LAYER TRANSITION, COMPUTATIONAL...
A brief outline of the experimental and theoretical investigation of boundary layer instability mechanisms on a swept leading edge at Mach 3.5 is presented. Transition is affected by wind tunnel noise only when roughness is present. Local bar-R sub * Reynolds number and k/eta sub * are useful correlation parameters for a wide range of free stream Mach numbers. Stability theory is in good agreement with the experimental cross flow vortex wavelength. These conclusions are briefly discussed.
Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER STABILITY, FLOW DISTRIBUTION, LEADING EDGES,...
A three dimensional analysis for fully viscous, subsonic, compressible flow is evaluated. An approximate form of the Navier Stokes equations is solved by an implicit spatial marching technique. Calculations were made for flow in a circular S duct and in the F 16 inlet duct. The computed total pressure contours and secondary flow velocity vectors are presented. Qualitative comparisons with experiment are shown for both ducts. The analysis is used to show how the cross section transitioning in...
Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, DUCT GEOMETRY, NUMERICAL FLOW...
Midspan aerodynamic measurements for a three vane-four passage linear turbine vane cascade are given. The vane axial chord was 4.45 cm. Surface pressures and loss coefficients were measured at exit Mach numbers of 0.3, 0.7, and 0.9. Reynolds number was varied by a factor of six at the two highest Mach numbers, and by a factor of ten at the lowest Mach number. Measurements were made with and without a turbulence grid. Inlet turbulence intensities were less than I% and greater than IO%. Length...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMICS, TURBINES, STATORS, TRANSITION POINTS, REYNOLDS...
Fluctuating wall pressure measurements have been made on centerline upstream of a blunt fin in a Mach 5 turbulent boundary layer. By examining the ensemble averaged wall pressure distributions for different separation shock foot positions, it has been shown that local fluctuating wall pressure measurements are due to a distinct pressure distribution, Rho(sub i), which undergoes a stretching and flattening effect as its upstream boundary translates aperiodically between the upstream influence...
Topics: NASA Technical Reports Server (NTRS), FINS, HYPERSONIC FLOW, PRESSURE OSCILLATIONS, SEPARATED FLOW,...
A data set containing measurements for approximately 100 shock crossings was compiled, and plasma wave profiles were plotted in conjunction with magnetic field data. Three emissions analyzed include upstream electron plasma oscillations, ion acoustic noise, and low frequency electromagnetic noise. The data demonstrate that the observed waves are consistent with generation by the kinetic cross-field streaming instability. Reanalysis of shock overshoots prompted by the presence of plasma feet...
Topics: NASA Technical Reports Server (NTRS), ACOUSTIC EMISSION, BOW WAVES, COLLISIONLESS PLASMAS,...
A schematic diagram of the new proposed Supersonic Low Disturbance Tunnel (SLDT) is shown. Large width two dimensional rapid expansion nozzles guarantee wide quiet test cores that are well suited for testing models at large angle of attack and for swept wings. Hence, this type of nozzle will be operated first in the new proposed large scale SLDT. Test results indicate that the surface finish of pilot nozzles is critical. The local roughness Reynolds number criteria R sub k is approx. = 10 will...
Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER TRANSITION, HYPERSONIC WIND TUNNELS, LOW...
