A proposed one-dimensional synthetic- aperture microwave radiometer could serve as an alternative to either the two-dimensional synthetic-aperture radiometer described in the immediately preceding article or to a prior one-dimensional one, denoted the Electrically Scanned Thinned Array Radiometer (ESTAR), mentioned in that article. The proposed radiometer would operate in a pushbroom imaging mode, utilizing (1) interferometric cross-track scanning to obtain cross-track resolution and (2) the...

Topics: NASA Technical Reports Server (NTRS), SYNTHETIC APERTURES, MICROWAVE RADIOMETERS, INTERFEROMETRY,...

Technology improvements in the recovery of water from brine are critical to establishing closed-loop water recovery systems, enabling long-duration missions, and achieving a sustained human presence in space. A genre of 'in-place drying' brine water recovery concepts, collectively referred to herein as Brine Residual In-Containment, are under development. These brine water recovery concepts aim to increase the overall robustness and reliability of the brine recovery process by performing drying...

Topics: NASA Technical Reports Server (NTRS), WATER RECLAMATION, DEWATERING, BRINES, CAPILLARY FLOW,...

Topics: DTIC Archive, LOPOSER, J. D., NATIONAL AERONAUTICS AND SPACE ADMIN LANGLEY RESEARCH CENTER HAMPTON...

A method is presented which permits the determination of the frequencies of vibrations of infinitely long thin cylindrical shells in an acoustic medium. Expressions are obtained for the displacements of the shell and for the pressures in the medium in the case of forced vibrations due to sinusoidally distributed radial forces. The results indicate that there is a low-frequency range, where no radiation takes place, and a high-frequency range where the external force provides energy which is...

Topics: DTIC Archive, BLEICH, H. H., BARON, M. L., COLUMBIA UNIV NEW YORK, *VIBRATION, *SHELLS(STRUCTURAL...

Topics: DTIC Archive, ROSHKO, ANATOL, NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON DC,...

Three types of war heads were detonated from a stationary posit ion to determine the extent to which passageways (provided for electrical leads) produce asymmetry in the rod pattern. In cylindrical war head 119a, the axis of a 2-in. conduit coincided with that of the cylinder. In war head 121, otherwise identical to 119a the conduit axis was displaced 0.250 in. from the cylinder axis. War head 119c was constructed with a flat side of chord length 6.25-in. while the axis of the conduit coincided...

Topics: DTIC Archive, PHILIPCHUK, V., NAVAL PROVING GROUND DAHLGREN VA, *WARHEADS, *GUIDED MISSILES,...

The fundamental acoustic pressure and particle velocity field and wave equations were derived for a vertically stratified, slightly viscous medium in which the small viscous effect was carried through only as a first-order correction term. The wave fields resulting from a single frequency point source in 3 particular media were derived and expressed as a sum of modes. The first 2 media were 1- and 2-layered homogeneous liquids bounded by perfectly reflecting planes, while the third was the...

Topics: DTIC Archive, Stone, Jack L., PRINCETON UNIV NJ DEPT OF ELECTRICAL ENGINEERING, *WAVE EQUATIONS,...

Topics: DTIC Archive, HELLERMAN, LEO, YALE UNIV NEW HAVEN CT LAB OF MARINE PHYSICS, *MATHEMATICAL ANALYSIS,...

Topics: DTIC Archive, BARON, M.L., BLEICH, H.H., COLUMBIA UNIV NEW YORK, *SHOCK WAVES, *CYLINDRICAL BODIES,...

The radiation impedance of a finite array of finite cylinders is determined by a boundary value problem technique. The final equations for the radiation impedance are stated without restriction on cylinder length or radius, cylinder spacing, or on the amplitude and phase of the radial velocity of the cylinders. The derivation is made for the case of each cylinder in the array having a uniform radial velocity over a sector of the cylinder, but the method of solution is not limited to such a...

Topics: DTIC Archive, Skorheim, Robert D, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *ACOUSTIC IMPEDANCE,...

Recent developments in structural research on circular ring-stiffened cylinders subjected to hydrostatic pressure have indicated that refinements of the standard strength analysis are required to account for the effects of discontinuities such as a heavy frame or bulkhead or variations in shell thickness. A procedure has been developed for computating axisymmetric stresses near these discontinuities in a cylinder in which the thickness of the material does not vary between a pair of stiffeners...

Topics: DTIC Archive, Short, Robert D, DAVID TAYLOR MODEL BASIN WASHINGTON DC, *CYLINDRICAL BODIES, *SHIP...

It is shown that for thin cylinders the internal pressure has a very significant effect on the natural vibration characteristics. For these cylinders, particularly those having smaller length-to-diameter ratios, the mode associated with the lowest frequency is in general not the simplest mode. In fact, the frequency spectrum may be so arranged that the frequency decreases with an increase in the number of circumferential nodes. The exact number of circumferential nodes which occur in the mode...

Topics: DTIC Archive, THOMPSON RAMO WOOLDRIDGE INC LOS ANGELES CA, *VIBRATION, *SHELLS(STRUCTURAL FORMS),...

The purpose was to determine the effect of diameter, temperature difference, and vibration intensity on the free convective heat transfer rate from horizontal cylinders subjected to transverse vibrations in air. The diameters of the cylinders were 0.085 and 0.25 inches. They were vibrated over a frequency range of 0 to 88 cycles per second and an amplitude range of 0 to 0. 35 inches. The surface temperature ranged from 138 to 201 degrees Fahrenheit, and the maximum vibration intensity was 29...

Topics: DTIC Archive, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING, *CYLINDRICAL...

A theoretical investigation is conducted for the radiation produced by a linear distribution of electric charge executing circular motion both inside and outside a cylindrical plasma column. The analysis includes the effects of compressibility and anisotropy of the plasma upon the radiation characteristics of the charge distribution. In the incompressible isotropic case, a dipole resonance phenomenon is exhibited for the first harmonic of the angular frequency of rotation of the charge when the...

Topics: DTIC Archive, POLYTECHNIC INST OF BROOKLYN NY DEPT OF AEROSPACE ENGINEERING AND APPLIED MECHANICS,...

The correct perfect fluid solution for forces and moments on a cylindrical tank of fluid undergoing small transverse displacements and rotations in a carried acceleration field was derived. A mechanical analogy was found which duplicates exactly the forces, moments and dynamic response of the fundamental fluid sloshing mode.

Topics: DTIC Archive, Schmitt, Alfred F, GENERAL DYNAMICS SAN DIEGO CA CONVAIR DIV, *SLOSHING, CYLINDRICAL...

A horizontal cylinder, located near the floor of a two dimensional wave channel was subjected to a train of non-linear gravity waves. The horizontal and vertical forces were measured and presented in dimensionless form. Experimental values of horizontal and vertical force coefficients are presented as functions of dimensionless wave height and dimensionless wave period. The dimensionless force coefficients predicted by a modified Morrison equation and a Froude-Krilov force are compared to...

Topics: DTIC Archive, Gehrman, Jr, Fred H, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *UNDERWATER OBJECTS,...

An experimental investigation was conducted to determine the effect of boattail geometry and simulated base rocket nozzle flow on overall base drag. All tests were performed at Mach numbers 2.50, 3.00 and 3.50. Reasonable prediction of base drag for the reported boattail shapes can be made by using approximate and empirical equations. A conical boattail produced less drag than the other boattail shapes investigated. The maximum nozzle stagnation to free- stream pressure ratio reported is 315....

Topics: DTIC Archive, Huerta, Joseph, ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD, *GUIDED...

The report presents the results of two series of tests which were made to investigate the commonly accepted criterion of instability for shell bodies. This criterion, as generally postulated, states that the total potential energy must be the same before and after buckling. It is an analytical consequence of this contention that the critical load at constant end shortening must be greater than at constant stress. Thus, there should be a difference between tests made in rigid and flexible...

Topics: DTIC Archive, Horton, Wilfred H, STANFORD UNIV CA, *PROJECTILE CASES, *SHELLS(STRUCTURAL FORMS),...

This report describes a new experimental technique evolved to measure the pressure distribution on the surface of a spinning body in a wind tunnel. The technique was successfully demonstrated by a series of wind tunnel tests of a spinning cylinder in crossflow. Surface pressure surveys were obtained on the cylindrical model for various tip speed ratios at subcritical, critical, and supercritical Reynolds numbers. The validity of the data was established by comparing the integrated pressure...

Topics: DTIC Archive, Miller, Miles C, EDGEWOOD ARSENAL ABERDEEN PROVING GROUND MD, *CYLINDRICAL BODIES,...

An experimental verification of the end effect theory of long cylindrical Langmuir probes in a high-speed collisionless plasma flow is reported. This effect is observed as a sharp departure from the predicted infinite probe current when a strongly negative probe is aligned with the flow. Both the height and the width of the ion current peak measured about the zero-degree attitude are strongly sensitive to ion temperature. The effect is verified for a mesothermal argon plasma with probe radius...

Topics: DTIC Archive, Mercure,Hubert P E, TORONTO UNIV (ONTARIO) INST FOR AEROSPACE STUDIES,...

In this report, interacting continuum theoreies are developed for cylindrical wave propagation in a bi-laminated, linearly elastic, composite medium, in this case a cylindrical circular infinite cavity perpendicular to the layering of the composite. The laminated medium is subjected at the cavity wall to a nonaxisymmetric shear and normal loading uniform in the direction of the cavity axis. Two microstructure theories are developed: the first simulates the effectively two-dimensional plane...

Topics: DTIC Archive, Benveniste,Yako, TEL-AVIV UNIV (ISRAEL) SCHOOL OF ENGINEERING, *LAMINATES, *CONTINUUM...

The use of amplitude and phase shading on a pair of concentric piston radiators has been employed as a means for controlling the acoustic radiation patterns for a small flush face transducer which is intended for use as a 75 kHz sound source in the underwater tracking of vehicles. A description is given of the design, construction and tests of several models of the composite piezoelectric ceramic transducer. Results indicate that this appears to be a feasible method for achieving a principal...

Topics: DTIC Archive, Auns,Vilnis Uldis, NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF, *SONAR PROJECTORS,...

During the past contract period the primary effort on this research program has been concerned with the buckling, postbuckling and vibrations of oval cylindrical shells and rings. Both analytical and experimental projects were undertaken. The work included linear as well as nonlinear analyses, and consideration of unreinforced and reinforced shells, as well as oval rings. (Author)

Topics: DTIC Archive, Kempner,Joseph, POLYTECHNIC INST OF NEW YORK BROOKLYN DEPT OF AEROSPACE ENGINEERING...

This report presents the equations that are programmed along with their derivations and the underlying theory. The code determines the current density and charge density induced on a model of an aircraft. The equations that are programmed result from patch zoning the aircraft model in order to obtain a solution to the frequency domain representation of the magnetic field intergral equation. The intent is to obtain solutions for a continuous spectrum that includes the low and resonant range of...

Topics: DTIC Archive, Sancer,Maurice I, TDR INC LOS ANGELES CALIF, *AIRCRAFT, *NUMERICAL ANALYSIS,...

This report presents charts suitable for preliminary dynamic design of deep underground protective structures in rock subjected to long-duration ground shock loadings produced by nuclear weapons. The charts were calculated using a theoretical model which consists of multilayered concentric cylinders of elastoplastic materials with a time-dependent, axially symmetric applied load representing the free-field stress. Each element in the cross section is assumed to be incompressible and its yield...

Topics: DTIC Archive, Britt,James R, ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS, *NUCLEAR...

A method for predicitng the field penetrating a circumferential opening in a cavity of revolution is described here. This method employs the method of moments and an aperture equivalence theorem. The former permits rotationally symmetric cavities with otherwise arbitrary contours. The latter improves the sensitivity of field computation when the aperture height is tiny and/or points deep within the cavity are sought. This method is evaluated with comparison to classical theory and experiment...

Topics: DTIC Archive, Schuman,H K, SYRACUSE UNIV N Y DEPT OF ELECTRICAL ENGINEERING,...

The objective of this investigation was to develop wrought 7075-T6 mechanical properties in a cast aluminum alloy component of net or near-net shape. A squeeze casting process was selected as the manufacturing process. Following a limited heat treatment optimization effort, mechanical properties of the squeeze cast 7075 alloy components were determined. Sidewall fracture toughness and transverse tensile properties in the closed base of the cylindrical components approached reported properties...

Topics: DTIC Archive, Thompson,John R , Jr, NAVAL SURFACE WEAPONS CENTER DAHLGREN LAB VA, *ALUMINUM ALLOYS,...

This study was carried out to determine the effects of plasticity and cutouts on the buckling of stiffened and nonstiffened cylindrical shells. Axial and end moment loading configurations were considered. The problem was investigated using the nonlinear and linear branches of the STAGS (Structural Analysis of General Shells) computer code. It becomes clear through this study that cutouts positioned within cylindrical shells create results that are not easily predictable using past shell...

Topics: DTIC Archive, Compton,Norton Leslie, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF...

Theoretical models of cementitious materials reinforced with either continuous or discontinuous, strong and stiff elastic fibres are discussed. Conditions for improved first-crack strength and post-cracking behaviour in such composites are considered. Some uncommon problems encountered in the fracture toughness testing of such composites are elucidated. (Author)

Topics: DTIC Archive, Argon,A S, MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING,...

The investigation of the disappearance of an organic plasticizer from a solid fuel pellet has been undertaken with emphasis on determining the mechanism that most effectively describes this phenomena. Actual experimental data was taken and several mathematical models designed and solved in order to evaluate the physical parameters associated with the disappearance of the plasticizer. Values of the solid state molecular diffusivity and the molecular distribution coefficient for the gas-solid...

Topics: DTIC Archive, Foglesong,Robert H, FRANK J SEILER RESEARCH LAB UNITED STATES AIR FORCE ACADEMY COLO,...

The final (minimum radius) state variables of a cylindrically imploded rotating liquid liner are computed as functions of p sub f, the maximum compression achieved, and u at infinity, the velocity the liner would attain if allowed to expand without restraint. For each choice of p sub f and u at infinity, the rotational speed is chosen to just stabilize the Rayleigh-Taylor modes on the inside surface. The acceleration of the inner surface is largest prior to turnaround, so that the rotational...

Topics: DTIC Archive, Book,David L, NAVAL RESEARCH LAB WASHINGTON D C, *LININGS, *NUCLEAR FUSION,...

A drop-table apparatus was evaluated by the U.S. Army Engineer Waterways Experiment Station (WES) to determine if it should be standardized and used for consolidating 6-in.-diameter cylindrical specimens of fresh concrete by the U.S. Army Corps of Engineers. Test specimens were fabricated from six concrete mixtures of three different slumps using both the drop-table method and the rodding and vibration methods, currently authorized by CRD-C 10-78 (ASTM C 192-76). Density and compressive...

Topics: DTIC Archive, Ragan,Steven A, ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS, *CONCRETE,...

This is the final report for Naval Air Systems Command Contract on the mutual coupling effect in a conformal array. It contains a brief administrative summary plus three attachments which give the technical details. (Author)

Topics: DTIC Archive, Lee,S W, ILLINOIS UNIV AT URBANA-CHAMPAIGN ELECTROMAGNETICS LAB, *ANTENNA ARRAYS,...

The work described herein concerns the determination of stability characteristics for time-dependent states of fluid flows or ordinary and partial differential equations in general. In particular nonlinear theories and simulations of bifurcation and stability are examined using energy methods, multiple-scale techniques and numerical procedures. (Author)

Topics: DTIC Archive, Davis,Stephen h, JOHNS HOPKINS UNIV BALTIMORE MD DEPT OF MECHANICS AND MATERIALS...

This study investigated the effectiveness of foam linings in mitigating shock waves in tunnels. A polyurethane foam liner of varying density, crush strength and thickness was modeled inside a 1 meter radius tunnel and an explosion of 1.25 kg of plastic explosive was simulated. Using CTH, an Eulerian- Lagrangian hydrodynamics code from Sandia National Laboratories, the overpressures were computed and compared graphically to determine the effect of varying each foam parameter. The walls of the...

Topics: DTIC Archive, Fondaw, Grant W, AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH, *SHOCK WAVES,...

Topics: DTIC Archive, Hayot, Fernand, OHIO STATE UNIV COLUMBUS DEPT OF PHYSICS, *TURBULENT FLOW, PRESSURE...

The effects of initial geometric and material property imperfections on the non-linear dynamic response of cylindrical shells subjected to an underwater explosion was investigated. Finite element and boundary element programs were used to perform the analysis of the dynamic response of these shells. The geometric and material modal imperfections were introduced into the finite element models. The dynamic response and deformation of the cylinder were then compared for each of the eight modal...

Topics: DTIC Archive, Kaufman, Robert E., NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *DEFECTS(MATERIALS),...

This report describes a series of calculations undertaken to compare the effects of geometric approximations/simplifications commonly made when setting up hydrodynamic code simulations of blast and flow in tunnel systems. The approximations are made to save computer resources by running the calculation in two, rather than three, dimensions. A two-dimensional calculation requires less computational time by a factor of one to two orders of magnitude. It also requires less memory to run and less...

Topics: DTIC Archive, Ekler, Robert G., S-CUBED ALBUQUERQUE NM, *TUNNELS, *GEOMETRY, *HYDRODYNAMIC...

Preliminary investigations of the structural properties of fiber-glass, filament-wound composites have shown that these materials have a great deal of promise for vessels that are structurally more efficient for storing fluids under pressure in a cryogenic environment than present vessels of metallic materials. This investigation was made to determine such structural properties through the use of a typical 18-in.-diam pressure test vessel. It was realized at the outset that providing a suitable...

Topics: DTIC Archive, Toth, J. M., Jr., DOUGLAS AIRCRAFT CO INC SANTA MONICA CA MISSILE AND SPACE SYSTEMS...

This final report for the Office of Naval Research Grant NOOOl4-92-J-117O concerns further VPI&SU research to develop and refine active structural acoustic control (ASAC) with active/adaptive structures. The focus is on the development and demonstration of advanced system design and optimization techniques for complex structures and disturbances, and realistic system implementations. This required a highly coordinated analytical and experimental research effort in the three areas of...

Topics: DTIC Archive, Fuller, Chris R., VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF...

A general approach developed for the computerized simulation of loaded gear drives is presented. In this paper the methodology used to localize the bearing contact, provide a parabolic function of transmission errors, and simulate meshing and contact of unloaded gear drives is developed. The approach developed is applied to spur and helical gears, spiral bevel gears, face-gear drives, and worm-gear drives with cylindrical worms.

Topics: DTIC Archive, Litvin, F., NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH...

We describe the development of a two-dimensional multimaterial reactive Eulerian hydrocode to model the detonation of condensed phase explosives, and use the code to model the projectile impact initiation of explosives. The code solves the Euler equations for the conservation of mass, momentum, and energy for an inviscid, compressible fluid using the Flux Corrected Transport algorithm. The condensed phase materials are modelled using a Mie-Gruneisen equation of state, while the...

Topics: DTIC Archive, Borg, Rodney A., DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA),...

An experiment-oriented investigation aimed at gaining insight and understanding of the physical phenomena that occur when a projectile impacts a thin barrier consisting of a uniform, coarse aggregate was performed at the U.S. Army Research Laboratory. The thin barrier target was an assembly of solid steel cylinders oriented in a 15-by-15 rod square-packed array. Each cylinder had a length-to-diameter ratio of 3.5 and a serial number imprinted on its rear surface to permit barrier reconstruction...

Topics: DTIC Archive, Bjerke, Todd W., ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD, *PROJECTILES, PLASTIC...

The overall objective of this program is to determine the instantaneous flow structure on delta wings at high angle of attack as well as from cylindrical bodies, which are subjected to basic classes of motion. New techniques of high image density particle image velocimetry provide the instantaneous vorticity fields and streamline patterns, thereby allowing interpretation of the underlying physics using critical point theory. This type of quantitative interpretation of the flow structure is...

Topics: DTIC Archive, Rockwell, Donald, LEHIGH UNIV BETHLEHEM PA DEPT OF MECHANICAL ENGINEERING AND...

This work reports on part of an effort to study the dispersion and extinguishment effectiveness of Halon and Halon alternative fire extinguishment agents discharged from N2-pressurized vessels. In the systems under consideration, as the agent exits from the vessel, thermodynamic and fluid dynamic instabilities lead to flashing and breakup of the agent into a two phase droplet/gaseous jet mixture. This occurs in a transition region relatively close to the vessel exit orifice/nozzle. Downstream...

Topics: DTIC Archive, Cooper, Leonard Y., NATIONAL INST OF STANDARDS AND TECHNOLOGY GAITHERSBURG MD,...

Report developed under contract No. F08630-01-1-0007. This report presents the results of an experiment study on the deformation and strength properties of several particulate systems under quasi-static compression for a variety of loading histories and strain rate conditions. To gain better understanding of the role of particle size distribution, initial porosity and loading history on compaction, triaxial compression data were obtained on selected cohesive systems: 1. Spherical silica...

Topics: DTIC Archive, Cazacu, Oana, FLORIDA UNIV SHALIMAR GRADUATE ENGINEERING AND RESEARCH CENTER,...

The temperature driven gas flow in a two-dimensional finite length microchannel and a cylindrical tube are studied numerically with the goal of performance optimization of a nanomembrane-based Knudsen compressor. The numerical solutions are obtained using direct simulation Monte Carlo method and discrete ordinate method for BGK model kinetic equation in a wide range of Knudsen numbers from 0.05 to 50. The length-to-height ratios from 5 to 30 were examined. Three different wall temperature...

Topics: DTIC Archive, Alexeenko, Alina A, UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES DEPT OF AEROSPACE...

This research was done as part of an effort to develop alternative fire suppressant technologies for aircraft engine nacelles. A circular cylinder array was designed, built, and placed in the AFIT roll-around low speed wind tunnel to model generic clutter inside an engine nacelle. A turbulence grid was fabricated to enable measurements of the effects of turbulence level, independent of airspeed, on the flow over different model configurations. The wind tunnel test section was 12 inches wide x...

Topics: DTIC Archive, Harder, Adam D, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF...

In this investigation the TMono cylindrical resonant cavity combiner is studied and characterized with the objective of improving the understanding of the design parameters of this microwave circuit. The study portion of the investigation involves presenting the fundamental theory of the cylindrical resonant cavity and coaxial diode circuits which make up a cylindrical resonant cavity combiner, the general modelling of two-port resonant cavities, and the equivalent circuit impedance relations...

Topics: DTIC Archive, Allen, Donald L, AIR FORCE WRIGHT AERONAUTICAL LABS WRIGHT-PATTERSON AFB OH AVIONICS...

In this investigation the TMono cylindrical resonant cavity combiner is studied and characterized with the objective of improving the understanding of the design parameters of this microwave circuit. The study portion of the investigation involves presenting the fundamental theory of the cylindrical resonant cavity and coaxial diode circuits which make up a cylindrical resonant cavity combiner, the general modelling of two-port resonant cavities, and the equivalent circuit impedance relations...

Topics: DTIC Archive, Allen, Donald L, AIR FORCE WRIGHT AERONAUTICAL LABS WRIGHT-PATTERSON AFB OH AVIONICS...