WorldCat Identities
Fri Mar 21 17:09:42 2014 UTClccn-n780228770.00The gateway reporter0.811.00Annual R & D activities report263351654n 78022877159225AVSCOMUnited States. Army. Aviation Systems CommandUS Army Aviation Systems CommandUSAAVSCOMcontainsVIAFID/157399963U.S. Army Aviation and Troop Commandlccn-n78087581United StatesNational Aeronautics and Space Administrationlccn-n79138699Ames Research Centerlccn-n79134855Langley Research Centerlccn-n83004067Litvin, F. L.(Faydor L.)orglccn-n80126316Lewis Research Centerlccn-n78091122United StatesNational Aeronautics and Space AdministrationScientific and Technical Information Branchlccn-n79069437Townsend, Dennis P.lccn-no2007056426Lewicki, David G.orglccn-n79063202United StatesArmylccn-n84232136Handschuh, Robert F.United StatesArmy Aviation Systems CommandHistoryUnited States.--Army Aviation Systems CommandUnited StatesGearingUnited States.--ArmyUnited States.--Army Troop Support CommandAeronautical instruments--Display systemsThree-dimensional display systemsStereoscopeFluid dynamicsAeronautics, Military--Equipment and suppliesComputer-aided designAeronautics, Military--ResearchU.S. Army Aviation and Troop CommandComputer graphicsMilitary helicopters--Accidents--InvestigationMilitary helicopters--Safety measuresIndustrial safetyLogisticsPersian Gulf War (1991)Computer simulationAeronauticsHeat--Transmission--Computer simulationManagementRotors (Helicopters)--TestingDepth perceptionComposite materials--Impact testingHelicopter flight simulatorsHelicopters--PilotingProcess control equipment industryGraphiteNavier-Stokes equationsAerofoilsAerodynamics, TransonicIterative methods (Mathematics)Computer integrated manufacturing systemsCoordinatesMathematical modelsMachine-tools--Numerical controlMachine-tools--Numerical control--ProgrammingAlgorithmsCost controlConjugate gradient methodsStructural optimizationAerodynamicsAirplanes--WingsTrailing edges (Aerodynamics)Gearing, Spur--TestingWakes (Aerodynamics)Pressure--MeasurementComposite materials--Delamination196919701971197219731974197519761977197819841985198619871988198919901991199219931994199513440302366956.7044DS79.744.L641422ocn299048018com19890.84Kalluri, SreerameshA data acquisition and control program for axial-torsional fatigue testingA computer program was developed for data acquisition and control of axial -torsional fatigue experiments. The mult-tasked, interrupt-driven program is capable of dual-channel control and six-channel data acquisition. It can be utilized to perform inphase and out-of-phase axial-torsional isothermal fatigue or deformation experiments. The program was successfully used to conduct inphase axial torsional fatigue experiments on 304 stainless steel at room temperature and on Hastelloy X 800 C. This paper describes the details of the software and gives some of the results generated to date. Failure of engineering components due to fatigue is a common occurrence in the aerospace and automotive industries. It is therefore necessary to characterize the fatigue behavior of materials so that the engineering components can be operated safely and reliably1383ocn034351023book19900.81Parrish, Russell VDetermination of depth-viewing volumes for stereo three-dimensional graphic displaysThree-dimensional (real-world) pictorial displays incorporating true depth cures via stereopsis techniques offer a potential means of displaying complex information in a natural way to prevent loss of situational awareness and provide increases in pilot/vehicle performance in advanced flight display concepts. Optimal use of stereopsis cueing requires an understanding of the depth-viewing volume available to the display designer. This report presents suggested guidelines for the depth-viewing volume from a empirical determination of the effective region of the stereopsis cueing (at several distances between the viewer and the cathode ray tube (CRT) screen) for a time-multiplexed stereopsis display system. The results provide the display designer with information that will allow more effective placement of depth information to enable the full exploitation of stereopsis cueing. Additionally, the data revealed the fact that increasing the viewer-CRT screen distances provides increasing amount of usable depth but decreases the field of view. A stereopsis hardware system that permits an increased viewer-screen distance by incorporating larger screen sizes or collimation optics to maintain the field of view at required levels would provide a much larger stereo depth-viewing volume1331ocn025060394book19900.81Carden, Huey DBehavior of composite/metal aircraft structural elements and components under crash type loads what are they telling us?Failure behavior results are presented from crash dynamics research using concepts of aircraft elements and substructure not necessarily designed or optimized for energy absorption or crash loading considerations. To achieve desired new designs which incorporate improved energy absorption capabilities often requires an understanding of how more conventional designs behave under crash loadings. Experimental and analytical data are presented which indicate some general trends in the failure behavior of a class of composite structures which include individual fuselage frames, skeleton subfloors with stringers and floor beams but without skin covering, and subfloors with skin added to the frame-stringer arrangement. Although the behavior is complex, a strong similarity in the static/dynamic failure behavior among these structures is illustrated through photographs of the experimental results and through analytical data of generic composite structural models. It is believed that the similarity in behavior is giving the designer and dynamists much information about what to expect in the crash behavior of these structures and can guide designs for improving the energy absorption and crash behavior of such structures1323ocn034352320book19900.79Parrish, Russell VStereopsis cueing effects on hover-in-turbulence performance in a simulated rotorcraftThe efficacy of stereopsis cueing in pictorial displays was assessed in a real-time piloted simulation of a rotorcraft precision 'hover-in- turbulence' task. Seven pilots endeavored to maintain a hover by visually aligning a set of inner and outer wickets (major elements of a real-world pictorial display) to attain the desired hover position. A full factorial experimental design was used. The display conditions examined included the presence or absence of a velocity display element (a velocity head-up display) as well as the stereopsis cueing conditions, which included nonstereo (binoptic or monoscopic, i.e., no depth cues other than those provided by a perspective, real-world display), three-dimensional stereo, and 'hyperstereo' (telestereopsis). Subjective and objective results indicate that the depth cues provided by the stereo displays enhanced the situational awareness of the pilot and enabled improved hover performance being achieved with the combined use of stereo and the velocity display element. Pilot control input data revealed that less control action was required to attain the improved hover performance with the stereo displays. Keywords: Stereoscopic display; Man machine system; Pictorial display; Cues stimuli; Piloted flight simulation; Hovering. (edc)1301ocn061196779book19920.84A basis for solid modeling of gear teeth with application in design and manufacture1291ocn060315501book19920.81An incremental strategy for calculating consistent discrete CFD sensitivity derivativesIn this preliminary study involving advanced CFD codes, an incremental formulation, also known as the delta or 'correction' form, is presented for solving the very large sparse systems of linear equations which are associated with aerodynamic sensitivity analysis. For typical problems in 2D, a direct solution method can be applied to these linear equations in either the standard or the incremental form, in which case the two are equivalent. Rerative methods appear to be needed for future 3D applications, however, where direct solver methods require much more computer memory than is currently available. Iterative methods for solving these equations in the standard form result in certain difficulties, such as ill-conditioning of the coefficient matrices, which can be overcome when these equations are cast in the incremental form; these and other benefits are discussed herein. The methodology is successfully implemented and tested in 2D using an upwind, cell-centered, finite volume formulation applied to the thin-layer Navier-Stokes equations. Results are presented for two laminar sample problems: (1) transonic flow through a double-throat nozzle, and (2) flow over an isolated airfoil1291ocn058970721book19910.81Baker, Donald JMechanical property characterization and impact resistance of selected graphite/PEEK composite materials1281ocn061048723book19890.81Computerized inspection of gear tooth surfaces1281ocn027944952book19910.81Litvin, F. LDetermination of real machine-tool settings and minimization of real surface deviation by computerized inspectionA numerical method is developed for the minimization of deviations of real tooth surfaces from the theoretical ones. The deviations are caused by errors of manufacturing, errors of installment of machine-tool settings and distortion of surfaces by heat-treatment. The deviations are determined by coordinate measurements of gear tooth surfaces. The minimization of deviations is based on the proper correction of initially applied machine-tool settings. The contents of accomplished research project cover the following topics: (1) Description of the principle of coordinate measurements of gear tooth surfaces; (2) Derivation of theoretical tooth surfaces (with examples of surfaces of hypoid gears and references for spiral bevel gears); (3) Determination of the reference point and the grid; (4) Determination of deviations of real tooth surfaces at the points of the grid; and (5) Determination of required corrections of machine-tool settings for minimization of deviations1241ocn060249612book19920.81Observations on computational methodologies for use in large-scale, gradient-based, multidisciplinary design incorporating advanced CFD codesThis paper briefly outlines how a combination of various computational methodologies could reduce the enormous computational costs envisioned in using advanced CFD codes in gradient-based optimized multidisciplinary design (MdD) procedures. Implications of these MdD requirements upon advanced CFD codes are somewhat different than those imposed by a 'single' discipline design. A means for satisfying these MdD requirements for gradient information is presented which appears to permit: first, some leeway in the CFD solution algorithms which can be used; second, an extension to 3-D problems; and third, straightforward use of other computational methodologies. Many of these observations have previously been discussed as possibilities for doing parts of the problem more efficiently; the contribution here is observing how they fit together in a mutually beneficial way1231ocn034352284book19900.81Meitner, Peter LComputer code for predicting coolant flow and heat transfer in turbomachinery1211ocn024959687book19900.81Influence of linear profile modification and loading conditions on the dynamic tooth load and stress of high contact ration gearsThis paper presents a computer simulation for the dynamic response of high-contact-ratio spur gear transmissions. High contact-ratio spur gear transmissions. High contact ratio gears have the potential to produce lower dynamic tooth loads and minimum root stress but they can be sensitive to tooth profile errors. The analysis presented in this paper examines various profile modifications under realistic loading conditions. The effect of these modifications on the dynamic load (force) between mating gear teeth and the dynamic root stress is presented. Since the contact stress is dependent on the dynamic load, minimizing dynamic loads will also minimize contact stresses. This paper shows that the combination of profile modification and the applied load (torque) carried by a gear system has a significant influence on gear dynamics. The ideal modification at one value of applied load will not be the best solution for a different load. High-contact-ratio gears were found to require less modification than standard low-contact-ratio gears1211ocn025063560book19900.81Pritchard, Jocelyn IDifferential equation based method for accurate approximations in optimization1201ocn062785667book19900.81Mavriplis, DimitriComputer simulation of gear tooth manufacturing processesThis report discusses the use of computer graphics to simulate gear tooth manufacturing procedures. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite elements models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms. (kr)1201ocn061195265book19910.81MacAlister, K. WNACA 0015 wing pressure and trailing vortex measurementsA NACA 0015 semispan wing was placed in a low-speed wind tunnel, and measurements were made of the pressure on the upper and lower surface of the wing and of the velocity across the vortex trailing downstream from the tip of the wing. Pressure data were obtained for both 2D and 3D configurations. These data feature a detailed comparison between wing tips with square and round lateral edges. A two-component laser velocimeter was used to measure velocity profiles across the vortex at numerous stations behind the wing and for various combinations of conditions. These conditions include three aspect ratios, three chord lengths, a square- and a round-lateral tip, presence or absence of a boundary-layer trip, and three image plane positions located opposite the wing tip. Both pressure and velocity measurements were made for angles of attack of 4 deg less then or equal to alpha less then or equal to 12 deg and for Reynolds. numbers of 1 x 10 deg less then or equal to Re less then or equal to 3 x 10 deg. The addition of a round-lateral edge to the wing Up was found to eliminate the secondary vortex near the wing Up, but had little effect on the downs characteristics of the trailing vortex. The increase in wing lift near the Lip because of the presence of the trailing vortex was evident in the surface pressure, but was not captured by circulation-box measurements. The circumferential velocity within the vortex was found to reach free-stream values and produce core rotational speeds as high as 44,000 rpm. The streamwise velocity within the viscous wake that is shed from the wing was observed to form islands of peak velocity in the spiraling sheet that feeds into the trailing vortex1201ocn025053261book19900.84Salpekar, Satish ACombined effect of matrix cracking and stress-free edge on delamination1201ocn024990350book19900.81Townsend, Dennis PSurface pitting fatigue life of noninvolute, low-contact-ratio gearsSpur gear endurance tests were conducted to investigate the surface pitting fatigue life of nonivolute gears with low numbers of teeth and low contact ratios for use in advanced applications. The results were compared with those a standard involute design with a low number of teeth. The gear pitch diameter was 8.89 cm (3.50 in.) with 12 teeth on both gear designs. Test conditions were an oil inlet temperature of 320 K an oil outlet temperature of 350 K a maximum Hertz stress of 1.49 Gpa (216 ksi), and a speed of 10,000 rpm. The following results were obtained: The noninvolute gear had a surface pitting fatigue life approximately 1.6 times that of the standard involute gear of a similar design. The surface pitting fatigue life of the 3.43-pitch AISI 8620 noninvolute gear was approximately equal to the surface pitting fatigues the same load but at a considerably high maximum Hertz stress1191ocn024996213book19870.84Phelps, Arthur EDescription of the U.S. Army small-scale 2-meter rotor test systemA small scale powered rotor model was designed for use as a research tool in the exploratory testing of rotors and helicopter models. The model, which consists of a 29 hp rotor drive system, a four blade fully articulated rotor, and a fuselage, was designed to be simple to operate and maintain in wind tunnels of moderate size and complexity. Two six-component strain-gauge balances are used to provide independent measurement of the rotor and fuselage aerodynamic loads. Commercially available standardized hardware and equipment were used to the maximum extent possible, and specialized parts were design so that they could be fabricated by normal methods without using highly specialized tooling. The model was used in a hover test of three rotors having different planforms and in a forward flight investigation of a 21 percent scale model of a U.S. Army scout helicopter equipped with a mast mounted sight. Keywords: Rotor model; Hover testing; Rotor scaling1161ocn029019915book19890.84Litvin, F. LTopology of modified helical gearsThe topology of several types of modified surfaces of helical gears are proposed. The modified surfaces allow absorption of linear or almost linear function of transmission errors caused by gear misalignment, and improvement of the contact of gear tooth surfaces. Principles and corresponding programs for computer aided simulation of meshing and contact of gears have been developed. The results of this investigation are illustrated with numerical examples1162ocn232660047book19840.84Hilbert, Kathryn BA mathematical model of the UH-60 helicopter2011ocn031883853serial0.63U.S. Army Aviation and Troop CommandAnnual historical reviewPeriodicals1902ocn021978626book19900.81Let the flyer beware : Army aviation safety : a report1463ocn029650481book19930.81United StatesArmy logistics better approach needed to identify systemic causes of problem parts : report to the Chairman, Subcommittee on Readiness, Committee on Armed Services, House of Representatives1062ocn029901036book19920.81United States[Army accounting adjustments--Aviation Systems Command]761ocn003803444book19770.93United StatesPlanned realinement of two Army commands in St. Louis, Missouri : report of the Comptroller General of the United States711ocn033357240book19910.92Butler, Howard KDesert Shield and Desert Storm, an aviation logistics history, 1990-1991HistoryThe Iraqi invasion of Kuwait on August the 2nd, 1990, and the resultant decision by the President to deploy land, air, and naval forces to protect Saudi Arabia and the United Arab Emirates led, since August the 8th, 1990, to a steady, measured commitment of soldiers, sailors, airmen and supporting equipment to Southwest Asia. That commitment, which began approaching its apparent apex by early November, suddenly broadened on the 8th of that month when the President expanded the original defensive objective to entail the liberation of Kuwait. His policy addendum called for doubling the 200,000 men in Southwest Asia to about 400,000, and he gave Iraq a January the 15th, 1991 deadline to quit Kuwait or face massive military force. Overall American policy in this matter could, therefore, be considered roughly three-phased: one, the original defensive deployment of 200,000 strong, August 8-November 8, 1990; two, the reinforcement to attack strength of about 400,000, November 8, 1990, to January 15, 1991; and three, January 16, 1991, to February 27, 1991- war523ocn027131791book19920.86United StatesFinancial management weak financial accounting controls leave commodity command assets vulnerable to misuse : report to the Commander, U.S. Army Materiel Command91ocn049248273book19900.88Let the flyer beware Army aviation safety : a report71ocn021571195serial0.95Annual historical review : U.S. Army Aviation Systems CommandPeriodicals21ocn556187201book19900.47United StatesDecision ... DYNCorp.21ocn081967502book19940.73United States[Protest of Army contract award for service tool kits]21ocn070691175book19930.66United States[Protest of Army contract award for technical support ]21ocn703284324book19920.47United States[Protest of Army solicitation for swashplates]11ocn127385573serial1.00Gateway reporterNewspapers11ocn263064909serialThe gateway reporterPeriodicals11ocn013065049book1984EEO handbook : a ready reference on the EEO programHandbooks, manuals, etc11ocn506619095book19920.47United States[Protest of AVSCOM decision to reevaluate bids for support services]11ocn418533922book19910.47United States[Protest of Army contract award for helicopter cuff assemblies]11ocn192050433book19910.47United States[Protest of Army contract award for liquid storage tanks]11ocn016512773serial1.00United StatesAnnual R & D activities reportPeriodicalsFri Mar 21 16:01:04 EDT 2014batch34013