N74-18872# Honeywell, Inc., Lexington, Mass. (AD-771064; ECOM-0236-3) Avail: NTIS CSCL 09/1 The first six months of a program to achieve a 10.6micrometer (Hg.Cd)Te photodiode thermoelectrically cooled module is described. The feasibility of such a module has been clearly demonstrated. A quantum efficiency of 55%, bandwidth of 156 MHz, and a saturation current of 3 mA at 146K is achieved. The program will continue for another six months during which the TE cooler-detector interface will be demonstrated. (Modified author abstract) GRA N74-18873# Systems Research Labs., Inc., Dayton, Ohio. Jul. 1973 Ronald N. Hubbard, Harold L. Iffland, and Joseph Fraggiotti Nov. 1973 171 prefs (Contract F33615-72-C-1847; AF Proj. 6102) (AD-771754; SRL-6765; AFAL-TR-73-301) Avail: NTIS CSCL 09/1 A detailed definition of the facilities required for comprehensive investigation of a wide variety of electro-optical (E-O) imaging devices is presented. The types of E-O devices whose characteristics were quantified are: (1) camera tubes, (2) infrared image devices, (3) image intensifiers, and (4) solid state imaging devices. These devices were first analyzed to determine their internal and external design characteristics. Operating parameters were then evaluated so that the measurement techniques capable of quantifying their performance could be defined. The test configurations needed to test each parameter for each type of device were defined. Particular emphasis was placed on selecting test setups which permitted maximum commonality between device types to arrive at a modular and integrated facility. After the functional requirements for each piece of test equipment were established, a survey of sources of test equipment was conducted and off-the-shelf items were specified to the greatest extent practicable. (Modified author abstract) GRA N74-18874# Rome Air Development Center, Griffiss AFB, N.Y. ELECTRON BEAM MICROANALYSIS OF ELECTROCHEMICAL ATTACK ON THIN FILM NICKEL-CHROMIUM RESISTORS John J. Bart Oct. 1973 38 p refs (AF Proj. 5519) (AD-772677; RADC-TR-73-220) Avail: NTIS CSCL 09/1 The purpose of the report is to present the results of the electron beam microanalysis (EBM) studies which have led to the development of a model for the observed electrochemical reaction. The intent was to correlate, principally through use of an electron microprobe, the various chemical characteristics of the integrated circuit with the behavior of thin film nickel-chromium resistors. Other pertinent features of the devices were studied with several additional techniques including scanning electron microscopy and mass spectrometry. GRA SYNTHESIS OF COMPOUND SEMICONDUCTING MATERIALS AND DEVICE APPLICATIONS: GALLIUM NITRIDE LIGHT EMITTING DIODES D. A. Stevenson and H. P. Maruska Dec. 1973 216 prefs (Grant DAHC15-72-G-0006; ARPA Order 1644) (AD-772503; CMR-73-17) Avail: NTIS CSCL 09/1 The synthesis and characterization of hetero-epitaxial gallium nitride (GaN) films were undertaken with particular reference to the phenomenon of light emission. Gallium nitride was grown by the chemical vapor deposition technique using sapphire substrates. Techniques for characterization included optical, scanning electron, and transmission electron microscopy and measurements of various electrical and optical properties of the films. The thin films of GaN were doped during growth with zinc and magnesium to form n-i junctions. Such material provided the basis for the fabrication of m-i-n light-emitting diodes, which emitted light in the high-energy violet region of the visible spectrum with Mg doping and green light with Zn doping. (Modified author abstract) GRA The characteristics of thin-wire, finite-gap, half wave length and quarter wavelength dipoles fed with a length of two-wire transmission line were studied using matrix methods. Transmission line length and gap size were varied obtaining the complete solution (current distributions, impedance and far field beam patterns) in each case. Significant departures from the ideal dipole characteristics are found even for electrically small gap sizes and transmission line lengths. When the departures are small, they can be described adequately by the relative magnitude of cross polarized field components and by null fill-in. Cross polarization effects are minimized by choosing transmission line length equal to (wavelength) where n is an integer. Departures from ideal dipole performance are significantly increased by reducing dipole length and by current imbalance. Some of the effects noted have been verified experimentally. Author (GRA) N74-18877# Naval Research Lab., Washington, D.C. (AD-772529; NRL-MR-2695) Avail: NTIS CSCL 09/5 At microwave frequencies, the recently developed small signal arsenic-diffused-emitter transistors offer high gain, reasonable compression levels, and low noise figure at low-bias levels. These characteristics make them attractive for use in low-noise preamplifiers in RF front ends of a multiport phased-array radar receiver. This report describes the development of a two-stage common-emitter amplifier, operating between 800 and 1400 MHz, using conventional microstrip techniques having a spot noise figure less than 4.00 db, at a gain of 26.5 db. Computer-aided design routines were used to obtain final designs from transistor S-parameters. Noise figure and stability criteria are discussed. Author (GRA) N74-18878# Westinghouse Research Labs., Pittsburgh, Pa. THIN FILM DISPLAY SWITCHES Final Report, 1 Apr. 1971 31 May 1973 Thomas P. Brody, Peter C. Y. Chen, and Karl K. Yu Dec. 1973 77 prefs (Contract NO0014-71-C-0269; NR Proj. 215-169) (AD-772544; Rept-73-9F2-PRNTM-R1) Avail: NTIS CSCL 09/5 A thin film transistor analog of an MNOS memory device was proposed as a grey level storage element for a solid state X-Y addressed display panel. Work was performed on sputtered Si3N4 layers in combination with thermal SiO2 on silicon and sputtered SiO2 on CdS films, and memory behavior was observed, flat band voltage shifts of 5V being obtained with gate pulses of plus or minus 35V. A new system was constructed to allow fabrication in a single pumpdown cycle. A modified device using CdSe, SiO2 and A1203, with a floating metal gate, was designed and fabricated in the new system. An X-Y addressible matrix of memory and switching transistors was designed, intended to control an ac EL phosphor layer deposited directly on top of the thin film matrix. Individual memory devices were shown to be able to control the brightness of associated EL phosphor elements. The thin film layout of the matrix was completed and masks were designed. (Modified author abstract) GRA MIS capacitors were fabricated on n-type GaAs0.5PO.5 using a thermally grown chromium-doped insulator and chromium gate electrode. The fabrication procedures which lead to stable devices are described. The devices were exposed to both Co60 gamma rays and high-energy electrons. A qualitative model which relies on carrier injection and trapping in the GaAsP disordered region is proposed to explain the observed radiation-induced space charge buildup in the capacitors. Radiation-induced increases in the fast interface-state density were generally less than 15 percent of the pre-irradiation values and were found to be independent of radiation type and dose, as well as the gate bias applied during irradiation. Thermal annealing experiments show that the radiation-induced charge can be completely annealed at a temperature of 150C, independent of the gate bias applied during annealing. (Modified author abstract) GRA N74-18880# Naval Research Lab., Washington, D.C. PATTERNS AND POLARIZATIONS OF SIMULATED CONFORMAL ARRAYS Final Report J. K. Hsiao and A. G. Cha 13 Nov. 1973 24 p refs (NRL Proj. RO2-33) (AD-772530; NRL-7615) Avail: NTIS CSCL 09/5 A conformal array on a surface of small curvature can be approximated by a number of planar arrays, several of which may be excited simultaneously so as to achieve a performance similar to that of a conformal array. Since the main beam of a planar array can be steered to any direction in visible space, several arrays, each oriented in a different direction, can be steered cooperatively to form a single beam in a desired direction. A general formulation of the radiated field of such a configuration of arrays is developed with the aid of formulas which relate the components into which a vector is resolved in one orthogonal coordinate system with those into which the same vector is resolved in a second orthogonal coordinate system. (Modified author abstract) GRA N74-18881# Purdue Univ., Lafayette, Ind. School of Electrical Engineer. SHORT-PULSE SWITCHES FOR AIRBORNE HIGH-POWER SUPPLIES Final Report, 31 Jul. 1972 - 31 May 1973 David B. Miller and Hannis W. Thompson, Jr. Wright-Patterson AFB, Ohio AFAPL Nov. 1973 102 prefs (Contract F33615-72-C-2097; AF Proj. 3145) (AD-772815; AFAPL-TR-73-81) Avail: NTIS CSCL 09/1 Prototypes of both magnetically and optically activated high current, high voltage switches are fabricated and tested. Feasibility is demonstrated for both the silicon optically-activated and the indium antimonide, magnetically-activated switches. A nearintrinsic silicon switch shows resistance decrease of almost four orders of magnitude with radiation from Xenon flash lamps. Resistance increase of an InSb cube is demonstrated; this result leads to theoretical predictions of three orders of magnitude resistance increase for a corbino-disk device with modest fields (1-3 wb/sq m). Author (GRA) N74-18882# Defense Documentation Center, Alexandria, Va. DISPLAY DEVICES Report Bibliography, Mar. 1964- Aug. 1973 Jan. 1974 539 p refs (AD-772850; DDC-TAS-74-3) Avail: NTIS CSCL 09/5 The bibliography contains unclassified and unlimited citations on Display Devices. This report is topically arranged into the following subtopics: Section (1) Cathode Ray Tubes and Screens; (2) Head Up Display: (3) Television Display Systems; (4) Stereoscopic Display Systems; (5) Viewing Screens, and (6) Miscellaneous. These citations are studies and analyses relating to display systems techniques, equipment, electronic components, development, evaluation and design requirements. Corporate Author-Monitoring Agency, Subject, Title, and Personal Author indexes are included. Author (GRA) 10 ELECTRONICS Includes circuit theory; and feedback and control theory. For applications see: 09 Electronic Equipment. For related information see specific Physics categories. N74-18883 University of Southern Calif., Los Angeles. Larry Herbert Canter 1973 290 p Avail: Univ. Microfilms Order No. 73-31331 In order to fault test large scale integrated (LSI) circuit chips successfully, efficient algorithms are necessary. The physics of field effect devices, their usage as logic elements, and techniques for implementing dc, two phase, and four phase logic on LSI chips are presented. This material provides a basis for the development of fault test algorithms. The faults associated with an LSI chip, such as inversion errors or pinholes are investigated and enumerated. Fault test procedures are developed to detect and sometimes locate these faults. The first algorithm to be considered assumes that not more than a single fault occurs in the circuit. Two other specific algorithms are conceived that assume the possibility of more than one fault. Dissert. Abstr. N74-18884 Post Office Research Dept., London (England). AN EXPERIMENTAL FREQUENCY MULTIPLEX/ (R-316) Copyright. Avail: Issuing Activity An experimental frequency multiplex/demultiplex network suitable for a TE sub 01-mode long distance circular waveguide system is described. It is constructed in rectangular waveguide and covers the band 32-50 GHz. Each stage of frequency separation is achieved using directional filters composed of two identical 3db couplers and two identical bandpass or highpass filters. Methods of design and construction of the directional couplers and filters are described. Insertion loss and signal distortion performance of the assembled network are shown. Author N74-18885# Cambridge Univ. (England). Dept. of Engineer- A. T. Fuller 1973 27 p refs (CUED/B-Control/TR-50) Avail: NTIS HC $4.50 A second-order control system with a saturating controller and a random disturbance is considered. It is known that when the control signal preceding the saturator is a linear combination of state coordinates, the steady-state probability density in state space may be obtained by solution of the Fokker-Planck equation. It is shown that when the mean-square-error is minimized the saturator operates as a relay; and the optimal parameter of the switching line is calculated. The explicit results obtained make the system a useful test case for computational solutions of the Fokker-Planck equation, and in other investigations of nonlinear stochastic control systems Author N74-18886# Sandia Corp., Albuquerque, N.Mex. MICROCIRCUITS: IR STUDIES ENHANCED BY AN INTERACTIVE MINICOMPUTER SYSTEM B. Stiefeld 1973 9 p Presented at the IEEE Northeast Electron. Res. and Eng. Meeting, Boston, 6 Nov. 1973 Sponsored by AEC (SLA-73-5515; Conf-731103-1) Avail: NTIS HC $3.00 The determination of temperature across the surface of a microcircuit is frequently of importance during the design phases of a project. Noncontact IR techniques are a natural choice to perform this operation. Minicomputer-based techniques are described that minimize the problems of emissivity variation and radiance-to-temperature conversion that are associated with IR-scanning techniques. Data are acquired and displayed using interactive procedures which are intended to enhance the ability of the concerned designers both to obtain the exact data desired and to display them in the most desirable manner. Author (NSA) N74-18887# Carnegie-Mellon Univ., Pittsburgh, Pa. Dept. of Computer Science. A RELIABILITY MODEL FOR VARIOUS SWITCH DESIGNS IN HYBRID REDUNDANCY Interim Report Ashok Ingle and Daniel Siewiorek Oct. 1973 47 p refs (Contract F44620-73-C-0074; AF Proj. 9769) (AD-771663; AFOSR-73-2173TR) Avail: NTIS CSCL 09/2 Various switch designs for the hybrid redundancy scheme are studied. A reliability model for the switch is developed and the switch is shown to be a significant factor in the overall system reliability. A hybrid redundancy scheme with a triplemodular redundant (TMR) core may have a maximum attainable reliability for only a spare or two. Adding spares complicates the switch enough to cause the system reliability to actually decrease. There exist conditions under which the switch becomes so complex that simple TMR would yield a better solution. Models for fault-tolerant switch designs are also obtained. Finally, various designs are compared via their reliability models. Author (GRA) 11 FACILITIES, RESEARCH AND SUPPORT Includes airports; lunar and planetary bases including associated vehicles; ground support systems; related logistics; simulators; test facilities (e.g., rocket engine test stands, shock tubes, and wind tunnels); test ranges; and tracking stations. N74-18888 Duke Univ., Durham, N.C. PERFORMANCE CHARACTERISTICS OF A PNEUMATIC Avail: Univ. Microfilms Order No. 74-1129 The limitations and deficiencies of the conventional models of ground transportation have prompted the proposal of a number of innovative high speed systems for future urban and interurban mass transit. Those which appear to offer the most desirable operating characteristics are systems which utilize an enclosed guideway. The power requirements for high speed ground transportation are, however, potentially high. Since the power required for propulsion of surface vehicles at higher speeds is largely that needed to overcome aerodynamic drag, enclosed guideway systems, operated at reduced internal pressures, are proposed to offer a more practical means for high speed ground transportation. A pneumatic tube transportation system would propel carrier vehicles through tube guideways by the combined effects of continuous evacuation of the guideway length ahead of the vehicle and the admission of air at a higher pressure to the guideway behind the vehicle. Dissert. Abstr. N74-18889*# Universities Space Research Association, Charlottesville, Va. Lunar Science Inst. [SCIENTIFIC AND ADMINISTRATIVE ACTIVITIES AT THE LUNAR SCIENCE INSTITUTE] Semiannual Status Report, 15 Jul. 31 Dec. 1973 N74-18891*# National Aeronautics and Space Administration. Marshall Space Flight Center, Huntsville, Ala. TWO STAGE LIGHT GAS PLASMA PROJECTILE ACCELERATOR Patent Application Edward L. Shriver, David W. Jex, and Edward B. Igenbergs. inventors (to NASA) (NAS-NRC) Filed 29 Jan. 1974 10 p (NASA-Case-MFS-22287-1; US-Patent-Appl-SN-438147) Avail: NTIS HC $4.00 CSCL 14B A device for accelerating a projectile to extremely high velocities, composed of a light gas accelerator to impart an initial high velocity to the projectile and a plasma accelerator and compressor receiving the moving projectile and accelerating it to higher velocities, is described. A capacitor bank is discharged into a plasma generator in timed relationship to the position of the projectile so that the moving plasma drags the projectile along with it. Projectile velocities in the order of 20 kilometers per second, the average meteoroid velocity, can be attained. whereby the accelerator finds particular utility in the field of meteoroid simulation. N74-18892# Cranfield Inst. of Technology (England). for Transport Studies. NASA Centre MAGNETIC SUSPENSION AND GUIDANCE OF HIGH SPEED VEHICLES Final Report I. A. Alston, J. M. Clark, and J. T. Hayden Dec. 1972 53 p refs (CTS-2) Avail: NTIS HC $5.75 CSCL 13F Technical and economical assessments of magnetic suspensions for high speed vehicles and transport systems are reported. In these suspensions the suspending magnet takes the form of a powerful superconducting electromagnet that induces currents while it moves over conducting sheets or loops. A number of vehicle track designs are evaluated for operating cost effectiveness. It is shown that propulsion systems using power collected from the track are more expensive than those using power generated onboard the vehicle, and that the conducting sheet suspension is slightly more expensive than the null flux suspension. Author N74-18893# Joint Publications Research Service. Arlington, ENGINEERING INSTITUTE O. A. Valdner 28 Feb. 1974 12 p refs Transl. into ENGLISH from Izv. Vysshikh Uchebn. Zavedenii, Fiz. (Tomsk), no. 12, 1972 P 14-22 (JPRS-61358) Avail: NTIS HC $4.00 The various uses of charged particle accelerators, circular iris waveguides, and high-frequency separators are discussed. Author N74-18895*# National Aeronautics and Space Administration. Langley Research Center, Langley Station, Va. THE EFFECT OF WIND TUNNEL WALL INTERFERENCE ON THE PERFORMANCE OF A FAN-IN-WING VTOL MODEL Harry H. Heyson Washington Feb. 1974 232 p refs (NASA-TN-D-7518; L-9202) Avail: NTIS HC $6.00 CSCL 14B A fan-in-wing model with a 1.07-meter span was tested in seven different test sections with cross-sectional areas ranging from 2.2 sq meters to 265 sq meters. The data from the different test sections are compared both with and without correction for wall interference. The results demonstrate that extreme care must be used in interpreting uncorrected VTOL data since the wall interference may be so large as to invalidate even trends in the data. The wall interference is particularly large at the tail, a result which is in agreement with recently published comparisons of flight and large scale wind tunnel data for a propeller-driven deflected-slipstream configuration. The data verify the wallinterference theory even under conditions of extreme interference. A method yields reasonable estimates for the onset of Rae's minimum-speed limit. The rules for choosing model sizes to produce negligible wall effects are considerably in error and permit the use of excessively large models. Author C. A. Moses Dec. 1973 28 p (Contract DAAD05-70-C-0007) (AD-772945; AFLRL-27) Avail: NTIS CSCL 21/4 A laboratory especially designed for the study of fuel-related problems in the operation of turbine engines has been installed at the U.S. Army Fuels and Lubricants Research Laboratory. The air supply system provides a clean, smooth flow of air to the combustion test cell at rates up to 2.5 lbs/sec; pressures to 16 atm and temperatures to 1500F are possible at all flow rates. The fuel delivery system is capable of pumping fuels ranging in properties from gasoline to No. 5 diesel at flow rates of over 1 gpm and pressures over 1000 psi. Up to 50 channels of thermocouple and transducer signals are sampled; the data reduction is performed on-line with test results available Immediately. The system has been designed for maximum flexibility and growth. Conceivably, any combustion chamber and associated rig can be plugged-in, instrumented, and operated within the air flow capabilities of the laboratory. Author (GRA) N74-18898# Royal Aircraft Establishment, Bedford (England). Aero/Flight Dept. A FOUR DEGREES OF FREEDOM, COCKPIT MOTION MACHINE FOR FLIGHT SIMULATION L. H. Warton London ARC 1973 62 p refs Supersedes RAE-TR-72075; ARC-056 (RAE-TR-72075; ARC-34056; ARC-R/M-3727) Avail: NTIS HC $6.25. HMSO £2.25: PHI $8.80 A machine for reproducing aircraft motions on a flight Simulator cockpit, was developed. The four freedoms of the machine are actuated by hydraulic servos. The equipment is part of the piloted flight simulator facility used for research and development studies in the Aerodynamics Department of the Royal Aircraft Establishment at Bedford. The control and safety procedures used when operating the machine within the simulator facility, are described. The limitations of the performance achieved are discussed both with a view to finding ways to improve the existing machine, and to point out those particular aspects of design which need careful attention and uncompromising implementation on any future project. Author (ESRO) N74-18899# Army Foreign Science and Technology Center, Charlottesville, Va. TEST STAND FOR RESEARCH INTO THE EFFECT OF PHYSICAL PROPERTIES OF GASES ON THE CHARACTERISTICS OF A CENTRIFUGAL COMPRESSOR A. B. Barenboim 26 Jul. 1973 9 p refs Transl. into ENGLISH from Kholod. Ter. Tekhnol. (Kiev), 1970 p 90-95 (AD-771089; FSTC-HT-23-2153-72) Avail: NTIS CSCL 13/7 Design of a test stand for investigating the effect of physical properties of gases on the characteristics of centrifugal compressors is discussed. Results of the testing of a compressor with GRA nitrogen gas are reported. N74-18900# Scripps Institution of Oceanography, La Jolla, Calif. Advanced Ocean Engineering Lab. PARAMETRIC STUDY OF A COLUMN SUPPORTED FLOATING AIRFIELD 30 Jun. 1973 43 p Sponsored in part by ARPA prepared in part by Glosten (L. R.) and Associates, Inc. (Contract NO0014-69-A-0200-6012) (AD-771672; AOEL-48) Avail: NTIS CSCL 01/5 The report discusses the feasibility of construction of a large base or airfield at sea using stabilized legs. The legs, connecting struts, and other equipment would be transported by barge to the building site. There, the barge and payload would be flipped to the vertical and assembled with the option that the barge might or might not be included as a part of the platform. GRA N74-18801 Bunker-Ramo Corp., Westlake Village, Calif. N74-19468* TRW Systems, Redondo Beach, Calif. THE COSMIC DUST ANALYZER: EXPERIMENTAL EVALUATION OF AN IMPACT IONIZATION MODEL J. F. Friichtenicht, N. L. Roy, and D. G. Becker In NASA, Washington Evolutionary and Phys. Properties of Meteoroids 1973 p 299-310 refs (For availability see N74-19436 10-30) CSCL 14B 12 FLUID MECHANICS Includes boundary-layer flow; compressible flow; gas dynamics; hydrodynamics; and turbulence. For related information see also: 01 Aerodynamics; and 33 Thermodynamics and Combustion. N74-18901 Georgia Inst. of Tech., Atlanta. DAMPING OF AXIAL INSTABILITIES BY SOLID PROPELLANT ROCKET EXHAUST NOZZLES Ph.D. Thesis Bangalore Ananthamurthy Janardan 1973 166 p Avail: Univ. Microfilms Order No. 74-231 The results of an experimental investigation undertaken to determine the effects of various nozzle design parameters on the capabilities of typical solid propellant rocket exhaust nozzles to attenuate axial combustion instabilities are presented. The nozzles selected are representative of a single-ported submerged rocket nozzle (RN-I) and a multiple-ported rocket nozzle (RN-II). In pursuit of this objective several experimental studies were conducted with geometrically similar small-scale models of actual solid rocket nozzles. In addition to determining the attenuation provided by the small-scale models of the RN-I and RN-II nozzles, this investigation was also concerned with determining the dependence of solid rocket nozzle damping upon (1) the depth of the cavity surrounding a submerged nozzle, (2) the secondary flow rate issuing from the cavity of a submerged nozzle, (3) the geometry of the convergent section of a solid rocket nozzle, and (4) the number of nozzles present in a multiple-ported nozzle cluster. Dissert. Abstr. N74-18902 Colorado Univ., Boulder. EXPERIMENTAL STUDY OF THE TURBULENT STRUCTURE AND HEAT TRANSFER OF A TWO DIMENSIONAL HEATED JET Ph.D. Thesis Jawaid Bashir 1973 120 p Avail: Univ. Microfilms Order No. 73-32511 Results from the kinetic energy balance for the turbulent velocity in an ambient two dimensional jet and temperature fluctuation balance for a heated two dimensional jet are reported. The jet was found to be self preserving at and beyond the 40 diameters downstream. A location of x over D = 40 was selected to measure the energy balance for the turbulent velocity and the temperature fluctuation balance. The measurements for ambient jet were compared with the existing data. In both the energy balance and the temperature fluctuation balance, production was found to be the most dominant term followed by dissipation, diffusion and then convection. In addition velocity and temperature spectra were measured. Their dependence on the jet center line, on position across the jet and on Reynolds number was determined. N74-18903 City Univ. of New York. Dissert. Abstr. The instability of non-Newtonian capillary jets in laminar and turbulent flow was investigated. Employing the techniques of high speed photography, two sets of data were obtained. The first consisted of perturbing the jets at a prescribed frequency and measuring the change in amplitude of a disturbance wave with time. In this way, dispersion curves were obtained for a number of fluids. Jet stability was also described by measuring the breakup length, or coherent portion of the stream, as a function of the velocity for jets ejected horizontally into still air. A systematic study was conducted to determine the effects of varying the polymer concentration and nozzle dimensions on the breakup curve of jets of a viscoelastic liquid. The actual shape of the breakup curve depends upon the relative magnitude of the elastic forces which act to upgrade stability, and the aerodynamic forces that tend to have an opposite effect. Dissert. Abstr. N74-18904 Cincinnati Univ., Ohio. THE AERO/ACOUSTIC RESPONSE OF FINITE CHORD BLADE ROWS TO CIRCUMFERENTIAL INLET FLOW DISTORTION IN AN UNSTEADY, COMPRESSIBLE FLUID Ph.D. Thesis C. Thomas Savell 1973 137 p Avail: Univ. Microfilms Order No. 74-100 The problem is considered of non-uniform inlet flow transfer through a compressor of a jet engine. Two separate techniques are used to approximate the unsteady flow in the rotor. The first technique is the semi-actuator disc analysis which models the blade cascade as one dimensional wave guides. This method permits an extension from an isolated rotor to a compressor stage. Two parametric studies on the response of a loaded rotor to inlet distortions are done for a single rotor operating at off design conditions and a number of rotors operating at their design points. The second technique is based on unsteady thin airfoil theory. It is a more refined analysis capable of describing the effect of cascade solidity on the distortion transfer. The model consists of representing each blade by a moving doublet filament of finite length immersed in a compressible stream containing a velocity distortion. The study is limited to an unloaded, flat plate rotor. Dissert. Abstr. N74-18905 Utah Univ., Salt Lake City. FACE MASS ADDITION Ph.D. Thesis Avail: Univ. Microfilms Order No. 74-189 The objective was to investigate the statistical properties of the turbulent flow field, produced by normal injection of air through a slotted wall into a two-dimensional boundary layer, bounded by a supersonic stream. Particular attention was given to determining the pressure-velocity-gradient correlation, as well as both pressure and velocity intensity, spectra, and length scales. Statistical properties in the boundary layer were obtained using a rapid response static pressure probe and a constant temperature anemometer. The small high frequency static pressure probe was designed and fabricated to measure the fluctuating pressure intensity and the pressure spectra throughout the boundary layer. Dissert. Abstr. N74-18906 Virginia Polytechnic Inst. and State Univ., Blacksburg. THE INTERACTION OF A TURBULENT FLAT-PLATE Rao Venkateswara Arimilli 1974 156 p Univ. Microfilms Order No. 74-1073 The results of the mean-velocity measurements of the interaction of a turbulent flat-plate boundary layer with the wake of a circular mounted normal to the plate are presented for cylinder Reynolds numbers between 4,200 and 33,600. The results indicate that beyond 100 diameters downstream, the flow is similar when viewed discretely as a wake. Between 20 and 100 diameters, the flow is seen not to be similar partly because of the presence, in each of the planes parallel to the plate, of velocities higher than the uniform velocity that exists far from the plane of symmetry, and partly because such a similarity does not exist even in two-dimensional wakes. An explanation is given for the origin and the propagation of these higher velocities. Dissert. Abstr. N74-18907 University of Southern Calif., Los Angeles. Richard Scott Passamaneck 1973 73 p The viscous, radiating hypersonic flow past an axisymmetric blunt body is analyzed based on the Navier-Stokes equations. plus a radiative equation of transfer derived from the MilneEddington differential approximation. The fluid is assumed to be a perfect gas with constant specific heats, a constant Prandtl number, of order unity, a viscosity coefficient varying as a power. of the temperature, and an adsorption coefficient varying as the first power of the density and as a power of the temperature. The gray gas assumption is invoked, thereby making the adsorption coefficient independent of the spectral frequency. The method of matched asymptotic expansions is used in the analysis. It is shown that there is a far field precursor, composed of two regions. in which the fluid mechanics can be neglected for all practical purposes but are included for completeness. Dissert. Abstr. N74-18908 Colorado Univ., Boulder. Avail: Univ. Microfilms Order No. 73-32523 The flow of an ideal weightless incompressible fluid from a region of high pressure through a slit into a vacuum is discussed. Under certain assumptions on the growth of the slit, the flow is shown to be self-similar. Explicit formulas for the velocity components along the free surface are derived in terms of the (unknown) geometry of the surface. It is further shown that the velocity gradients near the point at which the jet separates from the wall vary approximately inversely with the square root of the distance from the separation point. An iteration scheme is used to numerically determine the shape of the free surface. The scheme provides a quick method of determining the flow of any fluid with a free surface, providing the flow can be considered self-similar. Dissert. Abstr. N74-18909 lowa Univ., Iowa City. SHOCK WAVE PROPAGATION IN A NON-UNIFORM, |