As part of a cooperative research program between NASA, McDonnell Douglas Corporation, and Wright Research and Development Center, a flow field investigation was conducted on a 7.52 percent scale windtunnel model of an advanced fighter aircraft design. The investigation was conducted in the Langley 16 ft Transonic Tunnel at Mach numbers of 0.6, 0.9, and 1.2. Angle of attack was varied from -4 degrees to 30 degrees and the model was tested at angles of sideslip of 0, 5, and -5 degrees. Data for...

Topics: NASA Technical Reports Server (NTRS), DELTA WINGS, FIGHTER AIRCRAFT, FLOW DISTRIBUTION, SUBSONIC...

Heat transfer rates and pressure distributions on three basic shapes were investigated at a nominal Mach number of 8 and free-stream Reynolds numbers from 0.43 to 3.4 million per foot. The models were a 0.4-in. nose radius, spherically blunted, 15-deg half-angle cone; two flat plate models with 0. 10-in. and 0. 50-in. cylindrical blunting; and a modified leading-edge plate with auxiliary planes to produce changing body shape within the elliptic flow region. The tests produced data showing the...

Topics: DTIC Archive, RHUDY, J. P., ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFS TN, *HEAT TRANSFER,...

Intensive experimental investigations have been carried out on a wing section with oscillating control including a streamlined gap between both wing parts. Steady as well as unsteady pressure distributions have been measured outside and inside the gap region for various incidences, flap angles and frequencies. In addition to the experimental investigations, a calculation procedure has been developed taking into account the real boundaries of the configuration including the gap region and...

Topics: DTIC Archive, Geissler,W, ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT NEUILLY-SUR-SEINE...

This work applies the Woodward USSAERO C code in a shortened form to the loads on an airfoil in the downwash field of a forward airfoil including the vortex impingement. The calculated pressure distributions are in general agreement with the experimental data, although both show the influence of the forward airfoil to be small in this case of a not-too-closely coupled line. The general trends of the loading on the rear fin both inboard and outboard of the vortex impingement are well...

Topics: DTIC Archive, Maddox, Arthur R, NAVAL ACADEMY ANNAPOLIS MD DIV OF ENGINEERING AND WEAPONS,...

186
186

Jun 9, 2011
06/11

by
Lightfoot, Michael C.; Ambur, Damodar R

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The Combined Loads Test System (COLTS) is a new structures test complex that is being developed at NASA Langley Research Center (LaRC) to test large curved panels and cylindrical shell structures. These structural components are representative of aircraft fuselage sections of subsonic and supersonic transport aircraft and cryogenic tank structures of reusable launch vehicles. Test structures are subjected to combined loading conditions that simulate realistic flight load conditions. The...

Topics: BOW WAVES, NONINTRUSIVE MEASUREMENT, BOUNDARY LAYERS, MACH NUMBER, LEADING EDGES, COHERENT...

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196

Jun 12, 2011
06/11

by
Chaboyer, Brian C.; Shao, Michae; Chaboyer, Brian C.; Carney, Bruce W.; Latham, David W.; Dunca, Douglas; Grand, Terry; Layden, Andy; Sarajedini, Ataollah; McWilliam, Andrew

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The metal-poor stars in the halo of the Milky Way galaxy were among the first objects formed in our Galaxy. These Population II stars are the oldest objects in the universe whose ages can be accurately determined. Age determinations for these stars allow us to set a firm lower limit, to the age of the universe and to probe the early formation history of the Milky Way. The age of the universe determined from studies of Population II stars may be compared to the expansion age of the universe and...

Topics: WIND TUNNEL TESTS, PRESSURE DISTRIBUTION, TORQUE, HORIZONTAL TAIL SURFACES, SEMISPAN MODELS, SCALE...

Woodward's panel method for subsonic and supersonic flow was improved by employing control points determined by exactly matching two-dimensional pressure at a finite number of points. The results show great improvement in the predicted pressure distribution of a flapped airfoil. With the paneling scheme of cosine law in both chordwise and spanwise directions, the method is shown to accurately predict leading edge and side edge suction forces of various configurations in subsonic and supersonic...

Topics: NASA Technical Reports Server (NTRS), LEADING EDGES, PRESSURE DISTRIBUTION, SUBSONIC SPEED,...

The time dependent Navier-Stokes equations in mass averaged variables are solved for transonic flow over axisymmetric boattail plume simulator configurations. Numerical solution of these equations is accomplished with the unsplit explict finite difference algorithm of MacCormack. A grid subcycling procedure and computer code vectorization are used to improve computational efficiency. The two layer algebraic turbulence models of Cebeci-Smith and Baldwin-Lomax are employed for investigating...

Topics: NASA Technical Reports Server (NTRS), BOATTAILS, FINITE DIFFERENCE THEORY, NAVIER-STOKES EQUATION,...

The Mars Entry Atmospheric Data System (MEADS) is being developed as part of the Mars Science Laboratory (MSL), Entry, Descent, and Landing Instrumentation (MEDLI) project. The MEADS project involves installing an array of seven pressure transducers linked to ports on the MSL forebody to record the surface pressure distribution during atmospheric entry. These measured surface pressures are used to generate estimates of atmospheric quantities based on modeled surface pressure distributions. In...

Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CIRCULATION, ATMOSPHERIC ENTRY, WIND...

Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. Work performed has shown that laboratory measurements of the millimeter-wave opacity of ammonia between 7.5 mm and 9.3 mm and...

Topics: NASA Technical Reports Server (NTRS), ABSORPTIVITY, ATMOSPHERIC MODELS, MICROWAVES, MILLIMETER...

The vortex dominated aerodynamic characteristics of a generic 65 degree cropped delta wing model were studied in a wind tunnel at subsonic through supersonic speeds. The lee-side flow fields over the wing-alone configuration and the wing with leading edge extension (LEX) added were observed at M (infinity) equals 0.40 to 1.60 using a laser vapor screen technique. These results were correlated with surface streamline patterns, upper surface static pressure distributions, and six-component forces...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CHARACTERISTICS, DELTA WINGS, FLOW DISTRIBUTION,...

Data were obtained on a 3-percent model of the Space Shuttle launch vehicle in the NASA/Ames Research Center 11x11-foot and 9x7-foot Unitary Plan Wind Tunnels. This test series has been identified as IA19OA/B and was conducted from 7 Feb. 1980 to 19 Feb. 1980 (IA19OA) and from 17 March 1980 to 19 March 1980 and from 8 May 1980 to 30 May 1980 (IA19OB). The primary test objective was to obtain structural loads on the following external tank protuberances: (1) LO2 feedline; (2) GO2 pressure line;...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC LOADS, EXTERNAL TANKS, FLOW DISTRIBUTION,...

A two-dimensional (theta,z) Navier-Stokes solver for multi-port wave rotor flow simulation is described. The finite-volume form of the unsteady thin-layer Navier-Stokes equations are integrated in time on multi-block grids that represent the stationary inlet and outlet ports and the moving rotor passages of the wave rotor. Computed results are compared with three-port wave rotor experimental data. The model is applied to predict the performance of a planned four-port wave rotor experiment....

Topics: NASA Technical Reports Server (NTRS), ROTOR DYNAMICS, MULTIBLOCK GRIDS, NAVIER-STOKES EQUATION,...

Temporally and spatially-resolved, two-component measurements of velocity in a supersonic hydrogen-air combustor are reported. The combustor had a single unswept ramp fuel injector and operated with an inlet Mach number of 2 and a flow total temperature approaching 1200 K. The experiment simulated the mixing and combustion processes of a dual-mode scramjet operating at a flight Mach number near 5. The velocity measurements were obtained by seeding the fuel with alumina particles and performing...

Topics: NASA Technical Reports Server (NTRS), COMBUSTION CHAMBERS, PARTICLE IMAGE VELOCIMETRY, HYBRID...

228
228

Jul 26, 2010
07/10

by
Vaughan, Victor L., Jr

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No Abstract Available

Topics: CHANNEL FLOW, TURBULENT MIXING, VELOCITY DISTRIBUTION, VISCOUS FLOW, WALL FLOW, CYLINDRICAL BODIES,...

An experimental examination of crossflow instability and transition on a 45 degree swept wing is conducted in the Arizona State University Unsteady Wind Tunnel. The stationary-vortex pattern and transition location are visualized using both sublimating-chemical and liquid-crystal coatings. Extensive hot-wire measurements are conducted at several measurement stations across a single vortex track. The mean and travelling-wave disturbances are measured simultaneously. Stationary-crossflow...

Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER FLOW, CROSS FLOW, FLOW STABILITY, SWEPT WINGS,...

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269

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The space shuttle is described as a vehicle which combines the advantages of airplanes and spacecraft, capable of repeatedly flying to space and back to earth. It will takeoff vertically, powered by two solid propellant boosters, which will be parachuted to earth at an altitude of about 40 km, for retrieval. New uses of space flight are anticipated as costs decrease, turn-around times shorten, and operations simplified. Color illustrations of the concepts are included.

Topics: BOUNDARY LAYER FLOW, FLAT PLATES, FREE JETS, PRESSURE DISTRIBUTION, FLOW DISTRIBUTION, STAGNATION...

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190

May 30, 2011
05/11

by
Westberg, Hal; Hall, Brad; Jackson, Andrea V

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The BOREAS TGB-10 team collected several trace gas data sets in its efforts to determine the role of biogenic hydrocarbon emissions with respect to boreal forest carbon cycles. This data set contains measured peroxide (H2O2 and total organic peroxides (ROOH)) and ozone concentrations as well as H2O2 and ROOH deposition velocities. These data were obtained at the SSA-OJP site from May to September 1994. The data are stored in tabular ASCII files. Some important results were: (1) Ozone...

Topics: TRANSONIC WIND TUNNELS, PRESSURE DISTRIBUTION, PITCH (INCLINATION), ALGORITHMS, WIND TUNNEL TESTS,...

277
277

Jun 9, 2011
06/11

by
Grosveld, Ferdinand W

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The active acoustic and structural noise control characteristics of a double wall cylinder with and without ring stiffeners were numerically evaluated. An exterior monopole was assumed to acoustically excite the outside of the double wall cylinder at an acoustic cavity resonance frequency. Structural modal vibration properties of the inner and outer shells were analyzed by post-processing the results from a finite element analysis. A boundary element approach was used to calculate the acoustic...

Topics: ALGORITHMS, TURBULENCE MODELS, AIRFOILS, PRESSURE DISTRIBUTION, MATRICES (MATHEMATICS), VELOCITY...

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301

May 22, 2011
05/11

by
NON

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Gimballed scanning devices or instruments are the subject of this invention. Scanning is an important aspect of space science. To achieve a scan pattern some means must be provided which impart to the payload an oscillatory motion. Various forms of machines have been employed for controllably conferring on scanning instruments predetermined scan patterns. They include control moment gyroscopes, reaction wheels, torque motors, reaction control systems, and the like. But rotating unbalanced mass...

Topics: CAVITATION FLOW, COMPUTATIONAL FLUID DYNAMICS, IMPELLERS, TURBINE PUMPS, BOUNDARY CONDITIONS,...

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194

May 23, 2011
05/11

by
Armstrong, T. W.; Colborn, B. L

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This report covers work performed by Science Applications International Corporation (SAIC) under contract NAS8-39386 from the NASA Marshall Space Flight Center entitled LDEF Satellite Radiation Analyses. The basic objective of the study was to evaluate the accuracy of present models and computational methods for defining the ionizing radiation environment for spacecraft in Low Earth Orbit (LEO) by making comparisons with radiation measurements made on the Long Duration Exposure Facility (LDEF)...

Topics: PRESSURE DISTRIBUTION, SURFACE PROPERTIES, FLAT PLATES, SCHLIEREN PHOTOGRAPHY, PLUMES, FLOW...

Laminar fluid flow in a simplified fluidic amplifier is analyzed using finite difference numerical techniques. Numerical solutions to the two dimensional incompressible Navier-Stokes equations are obtained in terms of stream function and vorticity. These solutions are presented as contour plots of lines of constant stream function. The effect of various flow parameters, such as Reynolds number, outlet port loading, and deflection of the power jet are examined. Finite difference solutions are...

Topics: DTIC Archive, Healey,Anthony J, TEXAS UNIV AT AUSTIN DEPT OF MECHANICAL ENGINEERING, *MATHEMATICAL...

The hydraulic forces caused by annular pressure seals were investigated. The measured inlet and exit loss coefficients of the flow through the seals were much smaller than the conventional values. The results indicate that the damping coefficient and the inertia coefficient of the fluid film in the seal are not affected much by the rotational speed or the eccentricity of the rotor, though the stiffness coefficient seemed to be influenced by the eccentricity.

Topics: NASA Technical Reports Server (NTRS), ANNULAR FLOW, CENTRIFUGAL PUMPS, HYDRAULICS, LOADS (FORCES),...

Program was written to include integration of surface pressure in order to obtain axial-force, normal-force, and pitching-moment coefficients. Program was written in CDC FORTRAN for the CDC-6600 computer system.

Topics: NASA Technical Reports Server (NTRS), BLUNT BODIES, BODIES OF REVOLUTION, CDC 6600 COMPUTER,...

The study in the last 6 months has observed a clear evidence that the current two-equation models tend to under-predict flow separation and over-predict heat transfer rate near flow re-attachment regions. In hypersonic flow calculations, these model deficiencies appear to be even more pronounced. This is particularly true in the incapability of the model to predict the extent of the flow separation. Two major deficiencies of the current two-equation models in predicting complex hypersonic flows...

Topics: NASA Technical Reports Server (NTRS), AEROSPACE PLANES, BOUNDARY LAYER SEPARATION, HYPERSONIC FLOW,...

Results are presented for the cycle efficiency and specific power of simple and recuperated gas turbine cycles in which steam is generated and used to increase turbine flow. Calculations showed significant improvements in cycle efficiency and specific power by adding steam. The calculations were made using component efficiencies and loss assumptions typical of stationary powerplants. These results are presented for a range of operating temperatures and pressures. Relative heat exchanger size...

Topics: NASA Technical Reports Server (NTRS), FLUID INJECTION, GAS TURBINES, STEAM FLOW, THERMODYNAMIC...

Spin, the result of a mismatch in contact radii on either side of the point of rolling, has a detrimental effect on traction contact performance. It occurs in concentrated contacts having conical or contoured rolling elements, such as those in traction drives or angular contact bearings, and is responsible for an increase in contact heating and power loss. The kinematics of spin producing contact geometries and the subsequent effect on traction and power loss are investigated. The influence of...

Topics: NASA Technical Reports Server (NTRS), ANGULAR VELOCITY, ANTIFRICTION BEARINGS, KINEMATICS, SPIN,...

An analytical model and computer program has been developed to analyze supersonic, laminar separating flow fields over ramps. The important features of the model are its ability to include the two family nature of the supersonic flow field, the matching of supersonic and subsonic profiles in the transonic region (which aids in the selection of the solution for a particular problem when two exist, thus eliminating the problem of branching solutions), the inclusion of the normal momentum equation...

Topics: DTIC Archive, Miller,Gabriel, NEW YORK UNIV N Y DEPT OF APPLIED SCIENCE, *SUPERSONIC FLOW, *VISCOUS...

This report presents results from analyses of steady and unsteady flows about several configurations involving the wing of the F-5 fighter airplane. The analyses were performed using higher order panel methods and the configurations analyzed included the following: the clean wing (both in an unbounded and in a wind tunnel wall bounded atmosphere), the wing with an external missile store mounted at the wing tip, and the wing with an external missile store mounted on a pylon at the lower surface...

Topics: DTIC Archive, Dusto, A. R., BOEING MILITARY AIRPLANE CO SEATTLE WA, *WINGS, *POTENTIAL FLOW,...

223
223

Jul 10, 2010
07/10

by
KURASHVILI, A. Y.; PLEPIS, O. Y

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EIGHTY-SEVEN HEALTHY INDIVIDUALS WERE EXAMINED TO DETERMINE THEIR TOLERANCE OF CUMULATIVE CORIOLIS ACCELERATION. FORTY-EIGHT PERSONS TOLERATED IT WELL; THE OTHER 39 SHOWED SYMPTOMS OF VERTIGO AT DIFFERENT TIMES AFTER COMMENCEMENT OF STIMULATION. THE RHEOENCEPHALOGRAMS OBTAINED IN THE STUDY WERE PROCESSED MATHEMATICALLY. ANALYSIS OF THE MOST INFORMATIVE PARAMETERS OF THE 11 COEFFICIENTS OF EXPANSION OF THE REG CURVES IN THE FOURIER SERIES BY THE COMPUTER YIELDED THE INTEGRAL PARAMETER OF...

Topics: AERODYNAMIC CHARACTERISTICS, AIR FLOW, DELTA WINGS, SLENDER WINGS, VORTEX SHEETS, DATA ACQUISITION,...

Data were obtained on the performance of space shuttle flight instrumentation under simulated flight conditions. These conditions included ablating insulation material. The tests were conducted at a free-stream Mach number of 10 and tunnel stilling chamber conditions of 1800 psia and 1900 R. (Author)

Topics: DTIC Archive, Stallings,D W, ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFS TN, *SPACE SHUTTLES,...

The aerodynamic properties of a new class of missile airframes that are derived from the known supersonic flow fields past inclined circular and elliptic cones are discussed. The theoretical foundations and initial force and moment data have been presented recently elsewhere. The present paper advances this knowledge in several ways. Force and moment data for two waverider configurations are presented for Mach = 8, extending the previous data taken in the range Mach = 3 to 5. Surface pressure...

Topics: DTIC Archive, Rasmussen,Maurice L, AIR FORCE ARMAMENT LAB EGLIN AFB FL, *Lifting bodies, Conical...

Pressure distributions around circular and circular/strake cylinders were measured in a wind tunnel at Mach numbers from 0.6 to 1.2 with Reynolds number independently variable from 10,000 to 100,000. The local pressures are integrated over the cylinder surface to determine the variation of drag coefficient with both Mach number and Reynolds number. Effects of tunnel blockage are evaluated by comparing results from circular cylinders of various diameters at common Mach and Reynolds number...

Topics: NASA Technical Reports Server (NTRS), CYLINDRICAL BODIES, PRESSURE DISTRIBUTION, TRANSONIC FLOW,...

NASA Ames Research Center has conducted in-flight airload testing of some advanced thermal protection systems (TPS) at the Dryden Flight Research Center. The two flexible TPS materials tested, felt reusable surface insulation (FRSI) and advanced flexible reusable surface insulation (AFRSI), are currently certified for use on the Shuttle orbiter. The objectives of the flight tests were to evaluate the performance of FRSI and AFRSI at simulated launch airloads and to provide a data base for...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC LOADS, IN-FLIGHT MONITORING, LOAD TESTS, SPACE...

A potential flow inverse body method was used to generate a family of underwater bodies that would generally possess extensive laminar flow by the use of surface heat addition. Parameters specifying the pressure coefficient distribution were varied in order to find the limits of these parameters beyond which a body could not physically be generated. Length-to-diameter ratios and prismatic coefficients were computed as a function of the parameters. Specific cases representing the limits of...

Topics: DTIC Archive, Eisenhuth,J J, PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB,...

Wind tunnel tests to determine the pressure distribution on a space shuttle launch configuration consisting of a delta wing orbiter and a swept wing booster with canard and tip fins were conducted. Pressure data were obtained for the combined orbiter and booster and for the booster alone at Mach numbers from 0.6 to 1.3, angles of attack from minus 8 degrees to plus 10 degrees, and sideslip angles from minus 6 degrees to plus 6 degrees. Pressure data were also obtained for the booster alone...

Topics: NASA Technical Reports Server (NTRS), SPACE SHUTTLE BOOSTERS, SPACE SHUTTLE ORBITERS, SPACECRAFT...

As a preliminary step toward predicting the leeside thermal environment for winged reentry vehicles at flight conditions, a computational solution for the flow about the Shuttle Orbiter at wind tunnel conditions was made using a point-implicit, finite volume scheme known as the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA). The surface pressures resulting from the computational solution are compared with wind tunnel data. The results indicate that the dominant inviscid flow...

Topics: NASA Technical Reports Server (NTRS), AEROTHERMODYNAMICS, ANGLE OF ATTACK, COMPUTATIONAL FLUID...

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821

Jul 11, 2010
07/10

by
Steger, J. L.; Warming, R. F

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The conservation-law form of the inviscid gasdynamic equations has the remarkable property that the nonlinear flux vectors are homogeneous functions of degree one. This property readily permits the splitting of flux vectors into subvectors by similarity transformations so that each subvector has associated with it a specified eigenvalue spectrum. As a consequence of flux vector splitting, new explicit and implicit dissipative finite-difference schemes are developed for first-order hyperbolic...

Topics: AERODYNAMIC CONFIGURATIONS, STRUCTURAL ANALYSIS, TEST FACILITIES, THREE DIMENSIONAL FLOW, AIRFOIL...

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483

Jun 18, 2010
06/10

by
Hill, W. A., Jr.; Kaattari, G. E

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Force and pressure distribution studies to high angles of attack on all-movable triangular and rectangular wings in combination with body at supersonic speeds

Topics: ANGLE OF ATTACK, ANGLE OF ATTACK, PRESSURE DISTRIBUTION, RECTANGULAR WING, SUPERSONIC SPEED,...

The full scope of this program was to have included development tests, design and production of custom test equipment and acceptance and qualification testing of prototype and protoflight coupling hardware. This program was performed by Ball Aerospace Systems Division, Boulder, Colorado until its premature termination in May 1991. Development tests were performed on cryogenic face seals and flow control devices at superfluid helium (He II) conditions. Special equipment was developed to allow...

Topics: NASA Technical Reports Server (NTRS), COUPLERS, CRYOGENIC EQUIPMENT, FIXTURES, LEAKAGE, LIQUID...

In connection with the question on the applicability of test results obtained from cryogenic wind tunnels to the large-scale model the similarity parameter is referred to. A simple method is given for calculating the similarity parameter. From the numerical values obtained it can be deduced that nitrogen behaves practically like an ideal gas when it is close to the saturation point and in a pressure range up to 4 bar. The influence of this parameter on the pressure distribution of a...

Topics: NASA Technical Reports Server (NTRS), CRYOGENIC WIND TUNNELS, NITROGEN, REAL GASES, REYNOLDS...

Wind tunnel tests of an arrow wing body configuration consisting of flat, twisted, and cambered twisted wings were conducted at Mach numbers from 0.40 to 2.50 to provide an experimental data base for comparison with theoretical methods. A variety of leading and trailing edge control surface deflections were included in these tests, and in addition, the cambered twisted wing was tested with an outboard vertical fin to determine its effect on wing and control surface loads. Theory experiment...

Topics: NASA Technical Reports Server (NTRS), ARROW WINGS, BODY-WING CONFIGURATIONS, CONTROL SURFACES,...

The locations of total ozone stations and of stratospheric ozone samplings were presented. The samplings are concentrated in three areas: Japan, Europe, and India. Approximately 75% of the total ozone measurements are made with Dobson instruments which offer the best international measurements. When well calibrated their accuracy is on the order of a few percent. It is found that although the total ozone percent is similar in both hemispheres, the northern hemisphere has 3 to 10% more ozone...

Topics: NASA Technical Reports Server (NTRS), NORTHERN HEMISPHERE, OZONE, PERIODIC VARIATIONS, PRESSURE...

When a fine powder is dumped into a silo, the gas trapped by the particles will slowly escape by diffusing through the material. The corresponding uneven gas pressure distribution creates a body force that is taken into account through Darcy's law. By using spatial averaging, the formulation, even though essentially one-dimensional in space, includes effects due to the geometry of the container. An efficient and robust numerical scheme based on a DAE formulation is proposed and implemented....

Topics: DTIC Archive, Coffey, K A, NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATHEMATICS, *MATHEMATICAL...

A unique unsteady cascade experiment directed at providing fundamental aerodynamic data needed to verify or direct refinements to the basic model on unstalled supersonic torsional flutter in turbomachines is presented. In particular, the steady, quasi-static, and unsteady aerodynamics were determined for a multiple circular arc (MCA) airfoil cascade which modeled the tip section of an advanced design fan blade. The MCA cascade was harmonically oscillated in the torsional mode at a reduced...

Topics: DTIC Archive, Fleeter,Sanford, GENERAL MOTORS CORP INDIANAPOLIS IND DETROIT DIESEL ALLISON DIV,...

Calculating the lift, drag, and pitching moment coefficients for an airfoil from the static pressure distribution obtained from wind tunnel tests is routine task when steady flow is considered, but it is much more complicated when the airfoil is operating in an unsteady flow field, similar to that experienced by a helicopter rotor blade, produced by an oscillating wind tunnel. A data reduction routine capable of condensing the large numbers of data associated with the unsteady investigation, as...

Topics: DTIC Archive, Pickelsimer,Billy Murel, NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF, *COMPUTER...

The paper describes a multiple grid method for transonic flow calculations. The proposed scheme incorporates a generalized alternating direction method as the smoothing algorithm. Numerical experiments with this multigrid alternating direction (MAD) method indicate that it is both fast and reliable. (Author)

Topics: DTIC Archive, Jameson,Antony, NEW YORK UNIV N Y COURANT INST OF MATHEMATICAL SCIENCES, *POTENTIAL...

Provides a method for accurately determining weight distribution and ground pressure of wheeled and tracked vehicles.

Topics: DTIC Archive, ARMY TEST AND EVALUATION COMMAND ABERDEEN PROVING GROUND MD, *TEST METHODS, *TRACKED...

Experiments are described in which the pressure distribution on two model controllable-pitch propellers was measured. The pressure was measured at 40 locations on the blade surface with the propeller operating in both uniform and inclined flow. The discussion of the experimental technique includes a description of the hardware and data analysis systems. The accuracy of the measured pressures was comparable to the measured calibration accuracy, excluding unexpected loading effects observed on...

Topics: DTIC Archive, Jessup, Stuart D., DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA...

The primary purpose of the present report is to demonstrate how well the Euler equations in a supersonic marching program (SWINT) can predict the flow fields of bodies, wings, and wing-body combinations. The motivation was to see if if the Euler equations will predict the fin loads in highly vortical flow fields for cruciform missiles. Body-alone and wing-body flow fields were measured in the Bumblebee Program at a position where a tail might be placed. Those data, compared with the predictions...

Topics: DTIC Archive, Nielsen,J N, NIELSEN ENGINEERING AND RESEARCH INC MOUNTAIN VIEW CA, *VORTICES,...