ABOVE THE WING OF A SWEPT-WINGED AIRCRAFT J. A. Bagley (RAE, Farnborough, Engl.) 20 prefs (See N72-10009 01-01) 6. INFLUENCE OF A JET ON THE AERODYNAMIC PROPERTIES OF WINGS POSITIONED ABOVE THE JET NOZZLE W. Baumert and L. Harms (DFVLR, Goettingen, West Ger.) 20 prefs (See N72-10010 01-01) 7. THE INFLUENCE OF AN INCLINED JET ON THE AERODYNAMIC CHARACTERISTICS OF A CONTROL SURFACE M. Seidel (DFVLR, Brunswick) 28 prefs (See N72-10011 01-01) 8. FORCE AND DOWNWASH MEASUREMENTS WITH JET SIMULATION ON MODELS OF THE EUROPEAN AIRBUS IN A LOW SPEED WIND TUNNEL W. Geissler (DFVLR, Goettingen, West Ger.) 22 p refs (See N72-10012 01-02) 9. INVESTIGATIONS OF EXHAUST JETS OF TL-ENGINE MODELS E. Schwantes (DFVLR, Brunswick) 33 prefs (See N72-10013 01-28) 10. CALCULATION OF THE PRESSURE DISTRIBUTION ON AN AIRCRAFT FUSELAGE WITH EMERGING LIFTING JETS USING SINGULARITIES G. Schulz (DFVLR, Porz, West Ger.) 36 p refs (See N72-10014 01-01) 11. AERODYNAMIC CALCULATIONS FOR THE INTERFERENCE OF SEVERAL PROPELLER-JETS WITH AN AEROFOIL G. Loebert (Ver. Flugtech. Werke Fokker, Munich) 43 p refs (See N72-10015 01-02) E. Melzer and R. Wulf In DGLR Aerodyn. Interference Between Experiments were carried out in a low speed wind tunnel to determine jet aircraft/engine interference with several aircraft models. After a discussion of the similarity parameters of engine intake and exhaust models, some possibilities of jet generation are explained, including compressed air, motor-driven fans or propellers, and the use of compressed air for ejectors of turbines. The power plants involved are described, and their possibilities and limitations are discussed. ESRO N72-10006# Saab Aircraft Co., Linkoping (Sweden). INTERFERENCE EFFECTS FROM JETS ON AIRCRAFT STATIC STABILITY. WIND TUNNEL METHODS USED IN SWEDEN G. Bennich In DGLR Aerodyn. Interference between Aircraft and Engine Jet Apr. 1971 16 p (See N72-10004 01-01) Avail: NTIS HC $6.00/MF $0.95; ZLDI Munich: 54 DM The development of equipment for measuring jet interference in aircraft models is described. The main object of these tests was the determination of jet interference effects on the static stability of the twin engined SAAB 105 aircraft and the single engined SAAB-37 Viggen which has an ejector type of afterbody. Special supports enabled the measurement of yaw stability for the twin-engined aircraft; the single engined model support permitted variation in angle of attack and yaw. The supply of compressed air was regulated to simulate all engine settings. ESRO N72-10007# Messerschmitt-Boelkow-Blohm G.m.b.H., Munich (West Germany). Unternehmensbereich Flugzeuge-Entwicklung. TECHNIQUE OF PROPULSION SYSTEM SIMULATION WITH HIGH PRESSURE EJECTORS FOR SUBSONIC WIND TUNNEL MEASUREMENTS ON A FIGHTER AIRCRAFT MODEL WITH VERTICAL TAKEOFF CHARACTERISTICS [TECHNIK DER TRIEBWERKSSIMULATION MIT HOCHDRUCKEJEKTOREN BEI UNTERSCHALLWINDKANALMES TURBULENT AND LAMINAR JET PROPAGATION IN R. Schmidt and J. T. Heynatz In DGLR Aerodyn. Interference The kinematics and dynamic laws governing the propagation of a jet emerging from a rotating arm tip are derived for a fixed coordinate system. Using typical mixing laws for rectilinear jet propagation as an approximation, the cases of plane and round laminar and turbulent jets are compared. The spatial deviation of a jet in a rotor wake results from a further approximation. The transferability of the theoretical statements on jet propagation from one reference system to another is discussed. The principles of jet propagation in rotating systems are treated in a system of corrolated coordinates. The theoretical derivations are clarified with examples of jets with temperature equal to or higher than their environment. In addition, the characteristic properties of jet propagation are experimentally investigated using smoke photographs. ESRO SOME EXPERIMENTS ON AN ENGINE INSTALLATION ABOVE THE WING OF A SWEPT-WINGED AIRCRAFT J. A. Bagley In DGLR Aerodyn. Interference between Aircraft and Engine Jet Apr. 1971 20 p refs (See N72-10004 01-01) (RAE-TM-AERO-1271) Avail: NTIS HC $6.00/MF $0.95; ZLDI Munich: 54 DM Experiments are described for a possible large diameter turbofan engine nacelle installation above the wing of a transport aircraft. The current generation of turbofan engines for transport aircraft have nacelle diameters of about 3m, and as engine bypass ratio increases, the nacelles will become even larger. To fit such engines in the conventional position below the wings will be increasingly difficult. Tests were first made on a partial model of the wing and nacelle with the jet represented by blowing from an external supply. Interference between the jet and wing was investigated by measuring pressures on the wing. by surveys of the total-head distribution in the jet, and by schlieren and oil-flow photography. These tests were followed by force measurements in a low-speed wind tunnel on a model of swept wing and fuselage, fitted with a pair of free-flow nacelles. The results suggest that the lift-dependent drag of such an installation may be significantly larger than that of a conventional installation below the wing. Author (ESRO) N72-10010# Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt, Goettingen (West Germany). Abteilung Aerodynamik. INFLUENCE OF A JET ON THE AERODYNAMIC PROPERTIES OF WINGS POSITIONED ABOVE THE JET W. Baumert and L. Harms In DGLR Aerodyn. Interference Rectangular and swept wings were investigated; position, inclination and velocity of the jet were varied. Wing and nacelle were mounted separately so that the wind tunnel balance did not measure jet thrust. A simple determination of jet interference was possible with this arrangement. The jet decreased wing lift, for the ratio of jet velocity and free stream velocity from 2 to 17 the lift loss increased linearly with the velocity ratio. The lift loss also increased with jet angle. The induced pitching moment is dependent on velocity ratio and varies with position of the jet. ESRO N72-10011# Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt, Brunswick (West Germany). Inst. Aerodynamik. THE INFLUENCE OF AN INCLINED JET ON THE AERODYNAMIC CHARACTERISTICS OF A CONTROL SURFACE [DER EINFLUSS EINES GENEIGTEN STRAHLS AUF DIE AERODYNAMISCHEN EIGENSCHAFTEN EINES LEITWERKS] M. Seidel In DGLR Aerodyn. Interference between Aircraft and Engine Jet Apr. 1971 28 prefs In GERMAN (See N72-10004 01-01) Avail: NTIS HC $6.00/MF $0.95; ZLDI Munich: 54 DM The variations in lift of a freestanding control surface due to a round, cold, engine jet were investigated. The most important parameter in VTOL longitudinal stability is the inclination of the jet engine to the flow direction. The measurements show that inclined incident jets result in lift losses of the control surface and thus are generally unfavorable to longitudinal stability. An empirical formula is derived for the estimation of lift loss due to ESRO jet impingement. N72-10012# Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt, Goettingen (West Germany). Abteilung Aerodynamik. FORCE AND DOWNWASH MEASUREMENTS WITH JET SIMULATION ON MODELS OF THE EUROPEAN AIRBUS IN A LOW SPEED WIND TUNNEL [KRAFT- UND ABWINDMESSUNGEN MIT TRIEBWERKSSIMULATION AN MODELLEN DES EUROPAEISCHEN AIRBUS IM NIEDERGESCHWINDIGKEITSBEREICH] c02 W. Geissler In DGLR Aerodyn. Interference between Aircraft and Engine Jet Apr. 1971 22 p refs In GERMAN; ENGLISH summary (See N72-10004 01-01) Avail: NTIS HC $6.00/MF $0.95; ZLDI Munich: 54 DM Extensive wind tunnel measurements of the European Birbus, including jet simulation, are reported. The jet interference influence on longitudinal stability led to repositioning of the nacelles. Simulation with the improved engine position did not indicate any reduction in jet interference, whilst bypass jet simulation showed further stability deterioration. Near ground, on the other hand, a clear improvement of longitudinal stability was observed. Further investigation at higher Reynolds numbers is necessary. ESRO A systematic investigation of hot gas free jets, with an excess temperature of 550C, with critical nozzle pressure, and five differently shaped convergent nozzles is described. Large differences were noted with free jet measurements at lower nozzle Mach number. The exhaust jet emerged from the convergent nozzle with very high static overpressure, and accelerated to hypersonic speed within a core of approximately five nozzle diameters. The jet disintegration and the spatial jet propagation were less for the high speed jet than for a free jet with lower nozzle exhaust velocity due to weather turbulence. The jet propagation angle is almost the same for hot and cold jets, but thermal lifting forces resulted in a deformation of the ESRO circular cross section for horizontal hot gas jets. N72-10014# Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt, Porz (West Germany). Inst. fuer Angewandte Gasdynamik. CALCULATION OF THE PRESSURE DISTRIBUTION ON AN AIRCRAFT FUSELAGE WITH EMERGING LIFTING JETS USING SINGULARITIES [BERECHNUNG DER DRUCKVERTEILUNG AUF EINEM FLUGZEUGRUMPF MIT AUSTRETENDEN HUBSTRAHLEN MITTELS SINGULARITAETEN] G. Schulz In DGLR Aerodyn. Interference between Aircraft and Engine Jet Apr. 1971 36 р refs In GERMAN (See N72-10004 01-01) Avail: NTIS HC $3.00/MF $0.96; ZLDI Munich: 54 DM The influence of a lifting jet perpendicular to a cylindrical aircraft fuselage is theoretically calculated. The secondary action of the jet is twofold: ambient air is drawn in as an injector, whilst the external airflow around the jet is considered as that around a solid body. The injector action is determined by a half empirical relation. The injector is represented as a line sink in potential theory. The displacing action of the jet is represented by dipole distribution on the jet axis. Both sink and dipoles cause undue disturbances near the fuselage surface by velocity components normal to the contour. These disturbances can be corrected by additional singularities. The determination of these singularities is the essential problem of the investigation. ESRO N72-10015# Vereinigte Flugtechnische Werke-Fokker G.m.b.H., Munich (West Germany). AERODYNAMIC CALCULATIONS FOR THE INTERFERENCE OF SEVERAL PROPELLER-JETS WITH AN AEROFOIL [BERECHNUNG DER AERODYNAMIK DES VON MEHREREN STRAHLEN BEAUFSCHLAGTEN TRAGFLUEGELS] c02 G. Loebert In DGLR Aerodyn. Interference between Aircraft and Engine Jet Apr. 1971 43 p refs In GERMAN; ENGLISH summary (See N72-10004 01-01) Avail: NTIS HC $6.00/MF $0.95; ZLDI Munich: 54 DM The suitability of the lifting surface theory for V/STOL aircraft for the calculation of the aerodynamics of a wing immersed in one or more propeller slipstreams was investigated by comparison with experimental results. The comparison was conducted on the basis of lift, drag, pitching moment, normal-force distribution, and wake characteristics. The impact pressure distribution and field of direction in the airfoil wake are discussed. The influence of the main propeller-wing interference characteristics on the descent capability of propeller driven V/STOL aircraft is investigated. ESRO N72-10016# National Physical Lab., Teddington (England). Aerodynamics Div. BOUNDARY LAYER MEASUREMENTS ON THE WALLS J. L. Fulker Sep. 1970 13 prefs The results from measurements of the wall boundary layers around the working section of a low speed wind tunnel are given. These results show that the floor boundary layer is somewhat thicker than the wall values, probably due to the roughness of the floor. Author (ESRO) N72-10017# National Physical Lab., Teddington (England). Aerodynamics Div. A WIND TUNNEL STUDY OF THE WIND LOADING ON A MODEL COOLING TOWER OF IGLOO (CIRCULAR ARC GENERATOR) FORM R. W. F. Gould and W. G. Raymer May 1970 12 p refs (NPL-AERO-SR-040) Avail: NTIS The surface pressure distribution was measured on a rigid mode cooling tower shell in a uniform wind at a Reynolds number of 13.700,000 calculated on the base diameter. The full scale windspeed for buckling failure was estimated from tests on two flexible models. Limited information was obtained on the vibrational behavior of these shells in a wind. Author (ESRO) N72-10018# National Physical Lab., Teddington (England). Aerodynamics Div. A PROGRAMME OF RESEARCH INTO VISCOUS ASPECTS OF FLOW ON SWEPT WINGS B. G. Thompson, G. A. Carr-Hill, and B. J. Powell (Kingston Polytech.) Sep. 1970 69 prefs (NPL-AERO-NOTE-1100; ARC-32402; FM-4175; PERF-2947) Avail: NTIS Current research to produce forward and inverse design programs for swept wings is described briefly. Calculations of linearized velocities, boundary layer development, and of external streamlines from surface pressures are presented. Problems affecting airfoil design and testing in viscous, nominally two-dimensional flow are also considered. Author (ESRO) N72-10019# National Physical Lab., Teddington (England). Aerodynamics Div. FURTHER EXPERIMENTS ON THE DRAG OF PERFORATED SHROUDS L. R. Wootton and D. Yates Jul. 1970 22 prefs (NPL-AERO-1321) Avail: NTIS The load on perforated shrouds (designed to prevent vortex-induced oscillations) surrounding circular cylinders has been measured. The drag increases as the gap between the shroud and the cylinder increases, and may be a large proportion of the load taken by the combined cylinder and shroud. Author (ESRO) N72-10020# National Physical Lab., Teddington (England). SOME EXPERIMENTS ON A WIND TUNNEL WALL Experiments on a localized two-dimensional boundary layer bleed on the sidewalls of a transonic wind tunnel with slotted roof and floor are described. The slotted walls are shown to have a powerful alleviating effect upon the disruption of the tunnel longitudinal pressure gradient that such a bleed system tends to produce. Author (ESRO) N72-10021# National Physical Lab.. Teddington (England). A NOTE ON SUBSONIC LINEARISED THEORY FOR Formulae are given for the streamwise and spanwise components of perturbation velocity due to thickness, as predicted by subsonic linearized theory, in the neighborhood of the crank formed by the junction of two semi-infinite swept wings of different sweep angles. The implications of these formulae for the magnitude of the crank effect are discussed qualitatively, including the influence of free stream Mach number. Author (ESRO) N72-10022# National Physical Lab., Teddington (England). Aerodynamics Div. SEPARATION MEASUREMENTS ON A DELTA WING IN A SHOCK TUNNEL AT M=8.6 USING MONOCHROME AND COLOUR-SCHLIEREN PHOTOGRAPHY R. F. Cash and A. M. Catley Sep. 1970 14 p refs Original contains color illustrations (NPL-AERO-NOTE-1097; ARC-32399) Avail: NTIS The measurements were made on a 76 deg swept delta wing in a 400 mm (16 in) shock tunnel and the free stream Reynolds number was 49,000 cm (125,000 in) for stagnation conditions of 150 atmospheres and 2000 K. A series of schlieren photographs of the established separated flow, induced by spanwise steps and wedges fixed at the rear of the model, were taken in monochrome and color. The technique, equipment, and the relative merits of the two systems are discussed in detail. Author (ESRO) N72-10023# National Physical Lab., Teddington (England). Aerodynamics Div. THE MECHANICAL DESIGN OF AN ADJUSTABLE NOZZLE FOR THE NPL 25 in BY 20 in (635 mm BY 508 mm) TRANSONIC WIND TUNNEL N. G. Marcus Sep. 1970 28 prefs (NPL-AERO-NOTE-1098; ARC-32400) Avail: NTIS A description is given of the mechanical engineering design of a pair of steel flexible liners. These are positioned by simple motorized jack systems which easily adjust the flexible nozzle to control the tunnel Mach number. The aerodynamic loading. calculations, and design features are discussed. Author (ESRO) N72-10024# National Physical Lab., Teddington (England). Environmental Unit. A LINEAR THEORY FOR THE FLUCTUATING DRAG OF SIMPLE STRUCTURES IN TURBULENT FLOW J. B. Roberts Mar. 1971 37 prefs (NPL-AERO-1329) Avail: NTIS An approach was developed for predicting the drag spectrum of simple structures in turbulent flow. Expressions which directly relate the drag spectrum to the wave number spectrum of the turbulence are derived and the special case of isotropic turbulence is examined in some detail. For the case of a disk lattice in isotropic flow it has been possible to express the drag spectrum analytically. The theoretical drag spectra of a disk lattice and a square lattice are shown to collapse when scaled on an area basis. Comparisons are made between the present theoretical results, previous theoretical results, and experimental results on flat plates. Author (ESRO) N72-10025*# National Aeronautics and Space Administration. Lewis Research Center, Cleveland, Ohio. EFFECT OF CASING TREATMENT ON OVERALL AND BLADE ELEMENT PERFORMANCE OF A COMPRESSOR ROTOR Royce D. Moore, George Kovich, and Robert J. Blade Washington Nov. 1971 65 p refs (NASA-TN-D-6538; E-6119) Avail: NTIS CSCL 20D An axial flow compressor rotor was tested at design speed with six different casing treatments across the rotor tip. Radial surveys of pressure, temperature, and flow angle were taken at the rotor inlet and outlet. Surveys were taken at several weight flows for each treatment. All the casings treatments decreased the weight flow at stall over that for the solid casing. Radial surveys indicate that the performance over the entire radial span of the blade is affected by the treatment across the rotor tip. Author N72-10026*# National Aeronautics and Space Administration. Glenn A. Michell Washington Nov. 1971 37 prefs (NASA-TM-X-2405; E-8418) Avail: NTIS CSCL 20D Vortex generators were investigated as a means of controlling the throat boundary layer in a Mach 2.5 mixed-compression inlet. With or without throat bleed, the generators were unable to produce the inlet peak recoveries available with good performance bleed. Generators placed on the unbled inlet centerbody ahead of the cowl shock impingement point degraded inlet performance. Generators placed further aft on the unbled centerbody, but ahead of the throat, improved inlet performance at conditions where the terminal shock could cause boundary layer separation. Adding generators to the inlet with throat bleed reduced performance. Bleed aft of the generators degraded the vortex flow field. Author N72-10030# Boston Univ., Mass. Engineering Labs. TURBULENCE INDUCED ROLLING MOMENTS ON FINNED VEHICLES Interim Report Daniel G. Udelson Mar. 1971 32 p refs (Contract F19628-68-C-0148; Proj. AF-7659) (AD-724724; AFCRL-71-0094; SR-4) Avail: NTIS CSCL 19/7 Expressions are derived for the rolling moment on long cylindrical finned missiles moving through a turbulent fluid at zero angle of attack. The moment is a function of the time average and fluctuating velocity components in the turbulent boundary layer of the vehicle. Solutions for these velocities are found from the Reynolds' momentum equations by making suitable assumptions, and contain parameters which must be determined experimentally. Author (GRA) N72-10027# Boston Univ., Mass. Engineering Labs. AN INVESTIGATION OF VORTEX PATH AND STRENGTH OF FINNED MISSILES AT HIGH ANGLE OF ATTACK AND NUMERICAL CALCULATION OF INDUCED ROLLING MOMENT Interim Labs. Charles S. W. Wong Mar. 1971 73 p refs (Contract F19628-68-C-0148; Proj. 7659) (AD-725061; AFCRL-71-0092; SR-2) Avail: NTIS CSCL 19/1 The vortex paths and strengths generated by finless, planar and cruciform missiles have been measured in the subsonic wind tunnel. Measurements for the finless missile were taken at wind tunnel speeds of 70 and 100 m.p.h. and at angles of attack of 10, 15, 20 degrees. The planar and cruciform missile measurements were taken at wind tunnel speeds of 70 m.p.h. with angles of attack of 15 and 20 degrees for the planar fin and 15 degrees. for the cruciform fin. Computer program results have been generated for the vortex induced rolling moment on a missile with planar fins at a high angle of attack with the input vortex positions and strengths taken from the results of this report. Author (GRA) N72-10028# Boston Univ., Mass. Engineering Labs. (Contract F19628-68-C-0148; AF PROJ. 7659) N72-10029# Boston Univ., Mass. Engineering Labs. Daniel G. Udelson Mar. 1971 35 p refs A solution is found for the unsteady contribution to rolling moment on long cylindrical bodies with planar fins under ideal flow conditions due to vortices which are formed on the body at high angle of attack and washed past the fins at the tail. This contribution must be added to the steady state solution which was obtained in an earlier work. The theoretical development employs the classical Blasius contour integral. Author (GRA) N72-10031*# National Aeronautics and Space Administration. Ames Research Center, Moffett Field, Calif. FULL-SCALE WIND-TUNNEL TESTS OF A SMALL UNPOWERED JET AIRCRAFT WITH A T-TAIL Paul T. Soderman and Thomas N. Aiken Washington Nov. 1971 99 p refs Prepared in cooperation with Army Air Mobility Res. and Develop. Lab. (NASA-TN-D-6573; A-3135) Avail: NTIS CSCL 01A The aerodynamic characteristics of a full scale executive type jet transport aircraft with a T-tail were investigated in a 40 x 80 ft (12.2 by 24.4 meter) wind tunnel (subsonic). Static, longitudinal, and lateral stability, and control characteristics were determined at angles of attack from -2 deg to +42 deg. The aircraft wing had 13 deg of sweep and an aspect ratio of 5.02. The aircraft was tested power off with various wing leading- and trailing-edge high lift devices. The basic configuration was tested with and without such components as engine nacelles, wing tip tanks, and empannage. Hinge-moment data were obtained and downwash angles in the horizontal-tail plane location were calculated. The data were obtained at Reynolds numbers of 4.1 million and 8.7 million based on mean aerodynamic chord. The model had static longitudinal stability through initial stall. Severe tail buffett occurred near the angle of attack for maximum lift. Above initial stall the aircraft had pronounced pitch-up. characteristic of T-tail configurations. A stable trim point was possible at angles of attack between 30 deg and 40 deg (depending on c.g. location and flap setting). Hinge-moment data showed no regions with adverse effects on stick force. Comparisons of wind-tunnel data and flight-test are presented. Author N72-10032 National Lending Library for Science and Technology. Boston Spa (England). A NOMOGRAM FOR DETERMINING THE REYNOLDS NUMBER V. V. Sterligov 1971 5 P Transl. into ENGLISH from Izv. Vyssh. Ucheb. Zaved., Chern. Met. (Moscow), no. 4, 1971 p 147-148 (NLL-M-21096-(5828.4F)) Avail: Natl. Lending Library, Boston Spa, Engl.: 1 NLL photocopy coupon A method of plotting and using a nomogram for determining the Reynolds number is given. It can be used for determining modelling conditions, calculating the aerodynamics of furnaces, and other purposes. Author 02 AIRCRAFT Includes fixed-wing airplanes, helicopters, gliders, balloons, ornithopters, etc; and specific types of complete aircraft (e.g., ground effect machines, STOL, and VTOL); flight tests; operating problems (e.g., sonic boom): safety and safety devices; economics; and stability and control. For basic research see: 01 Aerodynamics. For related information see also: 31 Space Vehicles; and 32 Structural Mechanics. N72-10033*# National Aeronautics and Space Administration. Lewis Research Center, Cleveland, Ohio. MULTIPLE FAN INTEGRATED PROPULSION WING SYSTEM Patent Application Roger W. Luidens, inventor (to NASA) Filed 21 Jun. 1971 14 P (NASA-Case-LEW-11224-1; US-Patent-Appl-SN-154934) Avail: NTIS CSCL 01B A system for directing air against the wing flaps of STOL aircraft to produce both lift and forward thrust is described. Airpumps provide high pressure air to small tip turbine fans disposed spanwise under the wings and forward of the flaps; the fans then direct the air against the flaps to produce the lift and thrust. J.G.M. N72-10034# Messerschmitt-Boelkow-Blohm G.m.b.H., Munich (West Germany). Unternehmensbereich Flugzeuge. PRELIMINARY TESTS AND PERFORMANCE OF ROLLING VERTICAL TAKEOFF AND LANDING OF THE VJ 101 C-X2 WITH IGNITED AFTERBURNERS [VORUNTERSUCHUNGEN UND DURCHFUEHRUNG VON ROLLENDEN SENKRECHTSTARTS UND -LANDUNGEN MIT DER VJ 101 C-X2 MIT GEZUENDETEN NACHBRENNERN] O. Richarz, H. Heidrich, and V. Zeidler Bonn Bundeswehramt 1971 38 p In GERMAN; ENGLISH summary Sponsored by Bundesmin. der Verteidigung (BMVg-FBWT-71-13) Avail: NTIS; Bundeswehramt, Bonn: 25 N72-10035# National Physical Lab., Teddington (England). A NEW BASIS FOR AIRCRAFT NOISE RATING Starting with the definition of noise pollution level, it is shown that the incremental value of this quantity due to the occurrence of an aircraft noise provides a logical basis for rating the noise. This measure has simple additive properties which permit the same definition to be extended to an arbitary series of events, including the background noise and its fluctuations. By specifying reference values of certain parameters, a formula is evolved which is suitable for aircraft noise certification purposes; the relation of this measure to effective perceived noise level is discussed. Author (ESRO) N72-10036# Defense Documentation Center, Alexandria, Va. NOISE POLLUTION AIRPLANE NOISE, VOLUME 1 Bibliography, Aug. 1947 - Dec. 1970 Jun. 1971 147 p refs 2 Vol. (AD-724850; DDC-TAS-71-26-1) Avail: NTIS CSCL 20/1 The annotated bibliography is an unclassified compilation of references on airplane noise pollution in a series of bibliographies on environmental pollution. References deal primarily with effects of noise exposure on hearing, speech, communications and community/airport noise. Computer-generated indexes for corporate author-monitoring agency, subject, and title are included. requesting AD-722 910. Author (GRA) N72-10037# Naval Ship Research and Development Center, Washington, D.C. Aviation and Surface Effects Ratios. THEORETICAL PERFORMANCE OF A PURE JET FLAP ROTOR AT HIGH ADVANCE RATIOS Robert M. Williams and Charles L. Bernitt Dec. 1970 49 p refs (Proj. WF32.421.202) (AD-726706; TN-AL-189) Avail: NTIS CSCL 01/3 The theoretical performance of a jet flap rotor at advance ratios greater than 1.0 is examined. The rotor is four bladed with purely elliptical airfoils of fifteen percent thickness ratio. Each airfoil has two plenum chambers which supply air to slots located beneath the leading and trailing edges, respectively. The rotor operates in cruise at advance ratios greater than unity so that the 'retreating blade is immersed in reverse flow. The lift and moments are controlled by ejecting a jet sheet out of the trailing edge on the advancing side of the azimuth and both the leading and trailing edge on the retreating side of the azimuth. Standard blade element theory is used to calculate jet flap rotor performance thrust coefficients representative of actual full-scale rotor operation. It is shown that good performance can be obtained using the jet flap and that substantially better performance can be achieved using a circulation control airfoil. Author (GRA) N72-10038# National Transportation Safety Board, Washington, BRIEFS OF ACCIDENTS INVOLVING AMATEUR/HOME (PB-201438; NTSB-AMM-71-2) Avail: NTIS CSCL 01B The publication contains statistical, cause/factor and injury tables, accident rates and the briefs of accidents involving amateur built aircraft. Author (GRA) N72-10039# National Transportation Safety Board, Washington, D.C. Bureau of Aviation Safety. BRIEFS OF ACCIDENTS INVOLVING WEATHER AS A CAUSE RELATED FACTOR: US GENERAL AVIATION, 1968 Jun. 1971 196 p (PB-201437: NTSB-AMM-71-1) Avail: NTIS CSCL 01B The publication contains statistical, cause/factor and injury tables, accident rates and the briefs of accidents involving weather. Author (GRA) N72-10040# Quality Assurance Directorate (Materials), London (England). THE INFRA-RED ANALYSIS OF AIRCRAFT CABIN-GAS ATMOSPHERES D. J. Bishop and J. K. Corbett Oct. 1970 31 prefs (QAD-MATS-174) Avail: NTIS The analysis of the air-bleed cabin gas produced by Olympus and Pegasus engines has been carried out by infra-red spectrometry. The method utilizes a conventional double beam recording infra-red spectrophotometer equipped with a pair of multireflection long path cells. The lower limits of detection of the various contaminants listed in the specification have been determined both individually and in conjunction with large amounts of other impurities. This method has also been extended to cover air-bleed cabin gas samples which have been taken from development engines in which malfunctions of the engine components have been simulated. Author (ESRO) |