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N89-28497# National Aeronautical Lab., Bangalore (India).
Presented at the International Symposion on CFD, Nagoya (Japan), 28-31 Aug. 1989 (PD-CF-8924) Avail: NTIS HC A02/MF A01
A 3D laminar thin-layer Navier-Stokes solver is developed which employs finite volume spatial discretisation and Runge-Kutta time integration. The code is applied to compute vortex flow over a round leading edge delta wing, and the results are compared with experiment and an Euler simulation.
test results indicate that it is impossible to overcome the strong driving tangential force of the basic section by means of any of the trailing edge devices investigated.
ESA N89-28501 British Aerospace Public Ltd. Co., Preston (England). Military Aircraft Div. A DETAILED SURVEY OF THE FLOW PASSING THROUGH AN ASYMMETRIC CONTRACTION AND PARALLEL DUCT M. T. Stickland 16 Nov. 1988 44 p (BAe-WWT-RP-RES-AXR-000194-Pt-A; ETN-89-94958) Avail: British Aerospace Public Ltd. Co., Preston Lancs PR4 1AX, United Kingdom
A research prograrn was undertaken to reduce or remove an undesirable flow effect in a transonic wind tunnel. The effect is a four lobe swirl appearing in the working section. An experimental study was carried out in the wind tunnel using a model of the contraction and square duct, and existing software was used to numerically simulate the phenomena. The physical simulation was quite successful in reproducing the flow perturbation, while the numerical simulation failed. The flow anomaly is found not to be a problem with the normal types of test work carried out in the tunnel, but it casts serious doubts on the tunnel value in duct code validation work.
N89-28498*# National Aeronautics and Space Administration. Ames Research Center, Moffett Field, CA. CORRELATION OF PUMA AIRLOADS: EVALUATION OF CFD PREDICTION METHODS Roger C. Strawn, Andre Desopper, Judith Miller, and Alan Jones (Royal Aerospace Establishment, Farnborough, England ) Aug. 1989 22 p (NASA-TM-102226; A-89223; NAS 1.15:102226; USAAVSCOM-TM-89-A-001) Avail: NTIS HC A03/MF A01 CSCL 01A
A cooperative program was undertaken by research organizations in England, France, Australia and the U.S. to study the capabilities of computational fluid dynamics codes (CFD) to predict the aerodynamic loading on helicopter rotor blades. The program goal is to compare predictions with experimental data for flight tests of a research Puma helicopter with rectangular and swept tip blades. Two topics are studied. First, computed results from three CFD codes are compared for flight test cases where all three codes use the same partial inflow-angle boundary conditions. Second, one of the CFD codes (FPR) is iteratively coupled with the CAMRAD/JA helicopter performance code. These results are compared with experimental data and with an uncoupled CAMRAD/JA solution. The influence of flow field unsteadiness is found to play an important role in the blade aerodynamics. Alternate boundary conditions are suggested in order to properly model this unsteadiness in the CFD codes.
N89-28502 British Aerospace Public Ltd. Co., Preston (England).
A research program was undertaken to reduce or remove an undesirable flow effect in a transonic wind tunnel. The effect is a four lobe swirl appearing in the working section. An experimental study was carried out in the wind tunnel using a model of the contraction and square duct, and existing software was used to numerically simulate the phenomena. The physical simulation was quite successful in reproducing the flow perturbation, while the numerical simulation failed. The flow anomaly is found not to be a problem with the normal types of test work carried out in the tunnel, but it casts serious doubts on the tunnel value in duct code validation work.
N89-28499# Technische Univ., Delft (Netherlands). Inst. for
The data of the adjusted angles of the tipvanes used on the Kolibrie rotor blades and rods, are reported. Two measuring methods are applied: one method is based on determining the chord vector and the span wise vector of the tipvane. The other method is based on the angles of the mounting parts of the tipvanes. The theoretical background and the measurement procedure are not included. Due to the unreliability of the position of the chord vector and the span wise vector the results from the first method are not used. Calculations are carried out with the data from the second method, based on the angles of the mounting parts of the tipvanes.
N89-28503# Naples Univ. (Italy). Istituto di Aerodinamica.
The activities performed, up to March 1988, on theoretical modeling of high temperature hypersonic flows, are reported. The phases of the research program are related to: the critical analysis of the thermo-fluid dynamics modeling of hypersonic flows; the formulation in dyadic form of the full set of field equations in a parallel surface curvilinear system; the linear phenomendogical one-fluid theory; the formulation of nonlinear phenomenological relations and nondimensional field equations; the order of magnitude analysis for steady states; the failure of the linear phenomenology and identification of the proper physical necessary modeling for hypersonic flows; and the formulation of the closed set of field equations for the case of a reacting gas mixture in nonequilibrium with respect to an arbitrary number of internal exchanges of mass and energy. Single fluid and linear irreversible thermodynamics are considered. Interaction between mass and electromagnetic energy is supposed negligible.
N89-28500# Aeronautical Research Inst. of Sweden, Stockholm.
Wind tunnel tests are carried out at low speeds. The test program includes high negative flap angles and an angle of attack range of 180 deg. The test Reynolds number is 2,200,000. The
N89-28504# Deutsche Forschungs- und Versuchsanstalt fuer
available from NASA Scientific and Technical Information Facility, BWI Airport, MD at $13.00/set
1989 75 p Sponsored in part by the Deutsche Forschungsgemeinschaft, Bonn (DFVLR-FB-89-09; ISSN-0171-1342; ETN-89-95306) Avail: NTIS HC A04/MF A01; DFVLR, VB-PL-DO, Postfach 90 60 58, 5000 Cologne, Fed. Republic of Germany, 25.50 DM
Three-dimensional laminar hypersonic flows of perfect gas over blunt bodies are investigated numerically. The thin-layer Navier-Stokes equations are solved for the steady state using a semi-implicit finite-difference scheme. The robustness of the bow shock fitting routine has been improved for interactions with captured embedded shocks. Hypersonic flows over a spacecraft nose and a double ellipsoid are considered. Separated flow, shock-shock and shock-boundary layer interactions are simulated. Skin-friction lines and heat-flux distributions agree qualitatively with oil flow and thermographic pictures. The extension of the code to consider high-temperature effects and the problem of code validation difficulties due to lack of suitable experimental data are discussed.
N89-28740# Aix-Marseilles Univ. (France). Inst. de Mecanique
N89-28505# Deutsche Forschungs- und Versuchsanstalt fuer
The laser Doppler anenometry (LDA) three-component velocity data obtained for a 65 deg sweptback, cropped delta wing at a free stream Mach number of 0.85 is analyzed with the aid of a menu driven computer program. The program was developed to process the LDA data employing a linear or a weighted quadratic interpolation technique to compute velocities in the vortex core or at any other field point where no measurement data is available. Basic results obtained using the two techniques to compute velocities in the vortex core or at any other field point polation scheme are presented. Limited analysis related to the structure of the vortex and the development of the leeside flow field is made. A good correlation of LDA results with surface results obtained through oil flow/static pressure is found. Existence of a shock wave located above the vortex core is indicated. The weighted quadratic interpolation theory is concluded to give preferable results to these produced by linear technique.
N89-28506# Systems Control Technology, Inc., Arlington, VA. RISK MANAGEMENT FOR AIR AMBULANCE HELICOPTERS OPERATORS Final Report Rich Adams and Jack Thompson Jun. 1989 57 p Prepared in cooperation with Advanced Aviation Concepts, Jupiter, FL (Contract DTFA01-87-C-0014) (DOT/FAA/DS-88/7) Avail: NTIS HC A04/MF A01
This manual is intended to provide an easy reference for dealing with the operating pitfalls, the human frailties, and the risks in managing an air ambulance operation. It is not designed to give the operator step-by-step instructions. Rather, the manual describes techniques and tools that can be used to balance the demands of running a business with the need for maintaining safety. It provides pilot selection and training guidelines, as well as a review of a risk assessment technique that has proven successful. In addition, the manual recommends a workable format for establishing standard operating procedures to reduce risks. Finally, it highlights the key concerns that should be carefully considered from a risk management viewpoint. This operators manual is one of an integrated set of five Aeronautical Decision Making (ADM) manuals developed by the Federal Aviation Administration in a concerted effort to reduce the number of human factor related helicopter accidents. It can be used as one element of a comprehensive program for improving safety, reducing risk and, hopefully, the high cost of helicopter hull and liability insurance. The other four documents of the set are: (1) ADM for Helicopter Pilots (DOT/FAA/PM-86/45); (2) ADM for EMS Helicopter Pilots Learning from Past Mistakes (DOT/FAA/DS-88/5); (3) ADM for EMS Helicopter Pilots Situational Awareness Exercises (DOT/FAA/DS-8876); and (4) ADM for Air Ambulance Hospital Administrators (DOT/FAA/DS-88/8).
N89-28736# Princeton Univ., NJ. Dept. of Mechanical and
May 1989 Computer diskette supplement (data file): IBM compatible DS HD 5.25-inch formatted 1.2 MB using MS DOS 3.20 (For primary document see N89-28734 23-34) Avail: NTIS HC A11/MF A01; set of 5 computer diskettes available from NASA Scientific and Technical Information Facility, BWI Airport, MD at $13.00/set
N89-28738# Princeton Univ., NJ. Dept. of Mechanical and
Sponsored in part by CNRS, France Computer diskette supplement (data file): IBM compatible DS HD 5.25-inch formatted 1.2 MB using MS DOS 3.20 (For primary document see N89-28734 23-34) Avail: NTIS HC A11/MF A01; set of 5 computer diskettes
N89-28507# National Transportation Safety Board, Washington,
Two separate aircraft accidents investigated by the National Transportation Safety Board are compiled. The accident locations and their dates are as follows: Belleville, Illinois, August 22, 1987; and Pensacola, Florida, December 27, 1987.
positioning at least one satellite has to be in or near the zenith, and the others should be equally spaced around the zenith. The precision reached with the improved kinematic model is on the order of 1 cm; it decreases from 1 cm, using zero baselines, to 3 cm, using static baselines. A precision of 7 cm in horizontal positioning and 4 cm in vertical positioning is obtained with the model, using kinematic baselines.
N89-28508# Technische Univ., Berlin (Germany, F.R.). Wirtschaftswissenschaftliche Dokumentation. COMPETITION AND SAFETY IN AIR TRAFFIC Thesis (WETTBEWERB UND SICHERHEIT IM LUFTVERKEHR] Matthias-Wolfgang Stoetzer 1988 50 p In GERMAN; ENGLISH summary (TUB-Diss-Paper-128; ETN-89-94421) Avail: NTIS HC A04/MF A01
The relations between competition and safety in the air transportion market are investigated. The allegation that competition in the air transportion market necessarily results in a deterioration of flight safety is examined on theoretical grounds. Existing studies of the relationship of safety and competition in flight transportation are summarized. The development of flight safety in the USA before and after the Airline Deregulation Act of 1978 is analyzed. Theoretical reasoning and the empirical confirmation lead to the conclusion that economic regulation is not inevitable in order to secure a high level of safety in air transportion. The maintaining or the regulation of technical standards is advised.
05 AIRCRAFT DESIGN, TESTING AND
Includes aircraft simulation technology.
For related information see also 18 Spacecraft Design, Testing and Performance and 39 Structural Mechanics.For land transportation vehicles see 85 Urban Technology and Transportation.
04 AIRCRAFT COMMUNICATIONS AND
Includes digital and voice communication with aircraft; air navigation systems (satellite and ground based); and air traffic control.
For related information see also 17 Space Communications, Spacecraft Communications, Command and Tracking and Communications and Radar.
Aerospace Medical Research Labs., Wright-Patterson AFB, OH. SPECIFICATIONS AND MEASUREMENT PROCEDURES AND AIRCRAFT TRANSPARENCIES Final Report, Dec. 1987 - Jun. 1988 Peter T. LaPuma and John C. Bridenbaugh Sep. 1988 56 p (AD-A209396; AAMRL-TR-88-058) Avail: NTIS HC A04/MF A01 CSCL 01/3
This report is a summary of the specification requirements for optical quality for several military aircraft transparencies. It is intended to provide the design engineer with an easy reference to a majority of the accumulated historical information concerning optical quality.
N89-28509# Mitre Corp., McLean, VA.
An operational concept is presented for collision avoidance services which will be in place upon implementation of the Federal Aviation Administration (FAA) National Airspace System (NAS) Plan. This operational concept only discusses the ground-base portion of how the Air Traffic Control System (ATCS) provides flight safety by maintaining adequate aircraft separation. This concept discusses the aircraft separation assurance per the National Airspace System Requirement Specification (NASSRS). The objective is to describe the relationship among subsystems, facilities, information, and operators/users involved in the collision avoidance service. In addition, the elements and operations of the NAS Plan are mapped into the collision avoidance requirements stated in the NASSRS, NAS-SR-1000. Several types of block diagrams are used to illusrate systems connectively and operational flow. Scenarios are also derived to describe the collision avoidance process from a user's perspective.
N89-28512# Army Lab. Command, Watertown, MA. Material
This report provides a comparative analysis of two ultrasonic inspection procedures for Kaman Aerospace Corporation's K747 root end fittings. The procedure currently being used was originally developed by Truton under contract through Kaman Aerospace, the fabricator of the root end fitting. The other procedure is a revision of the existing Truton procedure which was prepared by the U.S. Army Materials Technology Laboratory (MTL). Both procedures were compared against a sample of ten previously rejected root end fittings.
N89-28510# Technische Univ., Delft (Netherlands). Faculteit
In DUTCH; ENGLISH summary (ETN-89-94804) Avail: NTIS HC A05/MF A01
The accuracy of static and kinematic vertical positioning using the global positioning system is studied both theoretically and by the analysis of measured data, with a view to depth measurements in open sea. The hitherto used kinematic model, which is of the type pseudo-range/phase, is rearranged in such a way that the position drift of the static baselines is eliminated. The influence of an error in the satellite position on the unknowns is analyzed; the linear relation between such an error and the positioning is derived by simulation. Simulations show that for a precise vertical
N89-28513# Office of the Secretary of Defense, Washington, DC. OPERATIONAL TEST PLAN CONCEPT FOR EVALUATION OF CLOSE AIR SUPPORT ALTERNATIVE AIRCRAFT Summary Report 31 Mar. 1989 130 p (AD-A208185) Avail: NTIS HC A07/MF A01 CSCL 15/6
The FY 1989 Defense Authorization Amendments and Base Closure and Realignment Act, Public Law 100-526, required the Director, Operational Test and Evaluation (DOT&E) to prepare an operational test plan to conduct a competitive fly-off of alternative aircraft for the Close Air Support (CAS) mission and to complete the test plan. The Act also directed the Secretary of Defense to conduct an independent assessment of ongoing studies and analyses related to selection of an aircraft for the CAS mission and to examine the feasibility of transferring the CAS mission from the Air Force to the Army. The Army and Air Force have jointly developed a list of requirements for a CAS aircraft. In addition, a Mission Need Statement (MNS) for a fixed wing aircraft has been developed and approved by the Joint Requirements Oversight Council, Office of the Chairman, Joint Chiefs of Staff. These requirements can be grouped into three principal categories:
07 AIRCRAFT PROPULSION AND
effectiveness in_ killing assigned targets, survivability and responsiveness. The USAF has proposed to replace the A-10 Thunderbolt, which is currently its primary CAS aircraft. Air Force assessments have concluded that the A-10, even with an engine modification, cannot survive on current and future battlefields while faster aircraft have significantly greater survivability. The Air Force has recommended that the A-10 be replaced by a modified version of the F-16, which has been designated the A-16.
Includes prime propulsion systems and systems components, e.g., gas turbine engines and compressors; and onboard auxilliary power plants for aircraft.
For related information see also 20 Spacecraft Propulsion and Power, 28 Propellants and Fuels, and 44 Energy Production and Conversion.
N89-28514# National Aerospace Lab., Tokyo (Japan).
A new optical coupling device for an airborne digital redundant system is described. For an onboard system, it is very important to increase reliability and safety, so a redundant system is applied. In a redundant system, in order to verify whether each operation is correct, it is necessary to compare it with the same time data from other systems. A new characteristic coupling device was developed and its features verified experimentally. This system has the following characteristics: (1) It has a simple hardware architecture in order to increase reliability and safety; (2) Synchronization and data exchange are separated in time, so this system utilizes the same hardware for these tasks; (3) To increase transfer speed, a broadcast method is used and the number of receivers is (redundancy-1); thus each system can transmit and receive simultaneously; and (4) An optical signal is used in order to increase transfer speed and this is effective for electric separation among systems. Finally, a discussion is presented of how to recognize the end of transfer without an interrupt signal in a digital computer.
N89-28516# Naval Air Propulsion Test Center, Trenton, NJ.
Presented here is statistical information relating to gas turbine engine rotor failures which occurred during 1984 in commercial aviation service use. Two hundred and six failures occurred in 1984. Rotor fragments were generated in 114 of the failures and, of these, 18 were uncontained. The predominant failure involved blade fragments, 90.3 percent of which were contained. Seven disk failures occurred and all were uncontained. Seventy percent of the 206 failures occurred during the takeoff and climb stages of flight. This service data analysis is prepared on a calendar year basis and published yearly. The data are useful in support of flight safety analyses, proposed regulatory actions, certification standards, and cost benefit analyses.
06 AIRCRAFT INSTRUMENTATION
N89-28517# Naval Air Propulsion Test Center, Trenton, NJ.
Statistics relating to gas turbine engine rotor failures which occurred during 1985 in U.S. commercial aviation service use are given. Two hundred and seventy-three failures occurred in 1985. Rotor fragments were generated in 150 of the failures, and of these 14 were uncontained. The predominant failure involved blade fragments, 94.4 percent of which were contained. Six disk failures occurred and all were uncontained. Fifty-seven percent of the 273 failures occurred during the takeoff and climb stages of flight. This service data analysis is prepared on a calendar year basis and published yearly. The data support flight safety analyses, proposed regulatory actions, certification standards, and cost benefit analyses.
Includes cockpit and cabin display devices; and flight instruments.
For related information see also 19 Spacecraft Instrumentation and 35 Instrumentation and Photography.
N89-28515# School of Aerospace Medicine, Brooks AFB, TX.
New concepts in HUD symbology, based on an understanding of the physiological mechanisms and ecological origins of the human visual system are described which may enable future HUD displays to serve as primary flight directors in addition to their current roles. The four key elements of this new symbology are: (1) prioritization of space according to the three-dimensional structure of visual attention, (2) an attitude display in the form of a global percept; (3) effective preattentive attitude cueing based on an ecologically valid simulation of the visual terrain during flight ; and (4) visual reference framing which depicts the roll of the aircraft relative to a stable horizon. Prototypes which illustrate the physiological HUD concept are presented. The specific advantage of the proposed symbology may be to allow the pilot to maintain effective attitude control while directing his attention towards the out-the-window environment.
N89-28518# Aeronautical Research Labs., Melbourne
Model tests of the air cooled exhaust augmentors proposed for the F/A-18 engine ground run-up facilities at RAAF Williamtown were undertaken, to confirm satisfactory aerodynamic behavior of the augmentor designs and to provide data for optimizing certain aspects of the designs. The tests were carried out on 1/45 scale models, using an unheated air jet to represent the engine exhaust. Geometric features were identified which had important influence on augmentor duct flow symmetry and the cooling flow augmentation ratio.
GRA Fiber optics communication techniques and their applicability in flight control are reviewed. The design of an optical digital system (communication principle, emitting sources, optical waveguides, receiver element, optical coupling) is outlined. The fundamentals of data communication systems aboard aircrafts, the technical requirements and operational behavior of optical components, and existing fly by light concepts are presented. Fly by light technology is compared with conventional technology. Further application of fiber optics elements in aircrafts are discussed.
N89-28519# Institut Franco-Allemand de Recherches, Saint-Louis
Presented at the 11th Symposium on Turbulence, Rolla, MO, 17-19 Oct. 1988 (ISL-CO-226/88; ETN-89-95033) Avail: NTIS HC A03/MF A01
Mean-flow and turbulence characteristics are measured in a high-temperature axisymmetric jet exhausting from an aero engine. The effects of exit Mach number and temperature on the jet flow field are studied. A laser Doppler velocimeter is used to map the flow characteristics over a range of Mach numbers from 0.46 to 0.84. Radial distributions of the mean axial velocity and the root mean square of the corresponding fluctuations are obtained at different axial stations in the flow. The various distributions are found to collapse when plotted in appropriate coordinates. The collapsed data can be approximated by a universal profile. The radial mean-velocity scans at various axial stations exhibit a strong similarity when compared in reduced lateral coordinates. The spread of the mixing layer decreases with increasing exit Mach number and temperature.
09 RESEARCH AND SUPPORT
Includes airports, hangars and runways; aircraft repair and overhaul facilities; wind tunnels; shock tubes; and aircraft engine test stands.
For related information see also 14 Ground Support Systems and Facilities (Space).
08 AIRCRAFT STABILITY AND
Includes aircraft handling qualities; piloting; flight controls; and autopilots.
For related information see also 05 Aircraft Design, Testing and Performance.
N89-28523# Naval Civil Engineering Lab., Port Hueneme, CA. JOINT SEALANTS FOR AIRPORT PAVEMENTS. PHASE 1: LABORATORY AND FIELD INVESTIGATIONS Final Report, Jul. 1986 - Dec. 1988 C. M. Inaba, M. C. Hironaka, and T. Novinson Dec. 1988 63 p (Contract DTFA01-86-1-02015) (DOT/FAA/DS-89/2-Phase-1) Avail: NTIS HC A04/MF A01
The objectives were to determine the essential characteristics of sealants for joints in Portland cement concrete (PCC) airport pavements that should be incorporated in specifications and select . best candidate sealants for field evaluation. Laboratory and field investigations of sealants were performed for data needed to meet these objectives. Major factors that sealants must be resistant to are: chemicals (jet fuel, hydraulic fluid, lubricating oil), physical (elongation, compression, intrusion), and environmental (thermal, sunlight, weathering). In laboratory specification conformance tests, only 3 of 18 (17 percent) of the sealants passed the tests. In field inspection of sealants and discussions with airport personnel, there was no one clearly outstanding performing seal that was identified; however, several airports favored the Dow Corning 888 silicone seal. There is a strong indication of material of specification (or both) deficiencies. Sealants selected for evaluation in Phase 2 have the following material compositions: silicone, polyurethane, coal tar/polyvinyl chloride, and chloroprene.
N89-28520# Naval Postgraduate School, Monterey, CA.
A comparison of two different autopilot configurations and their effect on missile response is presented. The comparison includes the steps taken in determining missile parameters from wind tunnel data and flight condition data. The missile parameters are coupled with two different autopilot configurations to determine any significant advantage of one configuration over the other. Pole placement is used in determining required autopilot feedback and feed forward gains. Simulations of each autopilot are conducted and the responses are compared.
GRA N89-28521# National Aeronautical Lab., Bangalore (India). Systems Engineering Div. MODEL SIMPLIFICATION BASED ON THE CONCEPT OF EQUIVALENT DEAD TIME Shaik Ismail Dec. 1988 38 p (NAL-TM-SE-8802) Avail: NTIS HC A03/MF A01
The concept of equivalent dead time and its use in the simplification of s-domain and z-domain higher order transfer functions (HOTF) is examined. A preliminary lower order transfer function (LOTF) is obtained by retaining a few dominant poles and zeros of the HOTF. This lower order model is then enhanced by including a pure time delay element. This element is related to the difference between equivalent dead times of HOTF and the preliminary LOTF. FORTRAN routines are developed for this procedure and several examples are given to illustrate the procedure.
N89-28524# Mitre Corp., McLean, VA.
This concept of operations is one of a set that in total describes the operation of the National Airspace System (NAS) when the projected upgrades are completed. The Direct User Access Terminal (DUAT) is a Federal Aviation Administration (FAA) program that enables pilots to obtain self-briefings and submit flight plans, much as they receive these services from Flight Service Stations (FSSs) and Automated FSSs (AFSSs) today; however, DUAT is provided by the private sector. DUAT Service capabilities and interactions between the user, the DUAT Service, and NAS subsystems are described. It is intended to provide a common perspective for personnel engaged in DUAT-related activities.
N89-28522# Technische Univ., Berlin (Germany, F.R.). Inst.
N89-28525# Mainz Univ. (Germany, F.R.).