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This book may be considered as a tribute to the works of Theodore Von Karman and Frank Wattendorf, his close associate and first Director of AGARD. Dr. von Karman (1881-1963), a well know aeronautical scientist with friends in many countries, was intensely interested in international scientific cooperation. Soon after NATO was established in 1949, he conceived the idea of an Advisory Group for Aeronautical Research and Development (AGARD) under the umbrella of NATO, and he succeeded in starting it as a group of NATO early in 1952. It became the first scientific agency of NATO. As the first Chairman of this NATO Agency, he developed a unique structure of technical-scientific Panels composed of scientists and engineers from the NATO countries who exchanged information, organized meetings, produced thousands of timely high quality publications, carried out joint projects, organized study groups for the NATO Military Committee and assisted each other in developing their research and development capabilities. AGARD grew to an organization with over 500 Panel members and some 1300 people contributed annually to lectures, in working groups, in study teams, etc. In 1997, forty-five years after its formation, AGARD was amalgamated with the Defence Research Group (DRG) to form the Research and Technology Organization (RTO). The book records the deliberations of the AGARD National Delegates Board and aspects of the work of the Aerospace Applications Studies Committee and of the Technical Panels which constituted the main activity of AGARD., Supercedes ADA375864 which was first published in case-bound paper form in 1999. Copies of this version may still be available from Research and Technology Organization, BP 25, 7 Rue Ancelle, F-92201 Neuilly-Sur-Seine CEDEX, France. The original document contains color images.

Thermal barrier coatings are an emerging technology which will enable either an increase in turbine inlet temperatures, or a reduction in the duty temperature of the blades and as a result, an extension of their life-cycle. This Workshop presented the state of the art, gave a description of the existing or emerging technologies, summarized our present knowledge of damage mechanisms, including microstructural, mechanical and thermal aspects, and reported on the benefits and drawbacks of the various families as perceived by engine manufacturers and users. A final discussion attempted to identify future R&D requirements., Papers presented at the 85th Meeting of the AGARD Structures and Materials Panel, held in Aalborg, Denmark, 15-16 October 1997. Text in English and French.

Modern defence systems must have a comprehensive surveillance capability. A key component of a surveillance system is the ability to detect and to locate radio signals. Requirements are both for global surveillance and for local areas in situations of rapid deployment of forces. The entire radio spectrum is of interest: long wave radio waves radio waves are used for strategic communications; the HF band remains one of the important frequency regions used by large and small countries for global and regional communications; the frequency range above 50 MHz through to the millimeter wave region is extensively used for both communications and surveillance purposes. Effects of the propagation medium play an important role in applying location techniques. For HF frequencies and below, the primary medium is the ionosphere; for higher frequencies important environmental effects are due to atmospheric refraction. In the entire radio band booth natural and man-made noise (including jamming) often play an important role in direction finding and location applications. Radiolocation techniques are concerned with the angle of arrival of a signal and location of an emitter

Anecdotal evidence suggests that soft tissue neck injury may be an occupational hazard for fighter pilots, particularly those in the later generation trainer and combat aircraft. Recent advances in helmet-mounted devices increase the potential for injury. There is an acute need for guidance on the maximum mass and mass distribution characteristics of head-mounted devices. The Symposium discussed the extent of risk and its control through the design of helmet-mounted devices, protective systems and aircrew training and conditioning. Keywords: High acceleration; Acceleration tolerance; NATO., Preface in English and French. Presented at the Aerospace Medical Panel Symposium, Munich, Germany, 24-28 Apr 89.

The Course presented a comprehensive review of fundamental procedures used during a fighter pre-development phase concentrating on basic mission requirements and aircraft sizing; aerodynamic design including performance, stability and control; materials, structural optimization and aeroelasticity; aircraft dynamics; engine intake and nozzle integration; and airframe store- compatibility Experimental and theoretical work has been demonstrated to play complementary roles and recommendations for future development of engineering tools are given in conclusion. Keywords: Fighter aircraft, Design, Aerodynamic characteristics, Materials, External stores, Engine inlets.

Papers were presented covering the following headings: Terrain reference navigation methods; Positioning by image processing or GPS; Mission and sensor management; New techniques and algorithms; Sensor technology; Systems applications. (edc), Preface in English and French.

This report is intended to review the status of cryogenic test technology based on information which has become available since the report of the Conveners' Group which was completed in 1981. The major events since the Conveners' report have been the completion and commissioning of the National Transonic Facility, the suspension of further work on the Douglas 4-CWT blowdown tunnel, the conversion of ONERA T2 for cryogenic operation, the steady progress with the DRVLR KKK, and the slow but positive progress with the ETW project, including installation of the pilot tunnel PETW. In addition there has been a recent AGARD Fluid Dynamics Panel Symposium on Wind Tunnels and Testing Techniques at Cesme, Turkey which produced several new papers of interest. Also, a meeting of specialists on cryogenic wind tunnel strain gauge balance technology was arranged by ETW in conjunction with ONERA at the Modane Test Centre. Additional keywords: NATO furnished; Materials; Instrumentation; Flow visualization; and Laser velocimetry., See also Rept. no. AGARD-AR-174, AD-A117 518.

The flight-test techniques for measuring continuous atmospheric turbulence are briefly outlined and available measurements of the power spectrum of atmospheric turbulence reviewed. The measured results are examined in order to determine how well they approximate the idealized models of a stationary Gaussian random process and of isotropic turbulence. Finally, some recent results on the variation with altitude of the probability distribution of the root-mean-square gust velocity are presented and the application of these results to operational response history calculations indicated., Presented at the Meeting of the Structures and Materials Panel (5th) on 29 Apr-3 May 1957 held in Copenhagen, Denmark. Text in English, Summary in French.

This AGARDograph presents a review of the extensive efforts made during the last 15 years to develop practical transonic wind tunnels and discusses their performance and limitations. Emphasis is placed on the design and operational characteristics of both types of modern transonic wind tunnels, that is, on wind tunnels with either longitudinally slotted or perforated test sections. Each chapter of the AGARDograph has been made as complete as possible, with its own series of figures and a separate list of references and bibliographical material.

Flight loads investigations are conducted primarily for the purpose of confirming wind-tunnel results by comparing the full-scale results with comparable wind-tunnel results as frequently as deemed necessary; assessing the maneuvering conditions required of the aircraft and determining the associated dynamic loading conditions for the maneuvers; and bringing to light loads problems as a result of conducting flight research. The research airplane program in the United States included from the beginning extensive programs on flight loads measurements. This Report summarizes some of the results from these investigations for three aircraft: the X-1 rocket-powered airplane; the X-5 variable-sweep airplane; and the XF-92A delta-wing airplane., Presented at the Meeting of the Structures and Materials Panel (5th) held in Copenhagen, Denmark from 29 Apr-3 May 1957. Text in English, summary in English and French.

A discussion is presented on the transition phenomena associated with distributed roughness, a correlation of three-dimensional roughness effects at both subsonic and supersonic speeds, and the effect of laminar boundary-layer stability as influenced by heat transfer, pressure gradients, and boundary-layer control on the sensitivity of laminar flow to distributed roughness. Results indicate that the transition-triggering mechanism of three-dimensional type surface roughness appears to be the same at supersonic and subsonic speeds. In either case, a Reynolds number based on the height of the roughness and the local flow conditions at the top of the roughness can be used to predict with reasonable accuracy the height of three-dimensional roughness required to cause premature transition. Neither the three-dimensional roughness Reynolds number nor the lateral spread of turbulence behind the roughness is changed to any important extent by increasing the laminar boundary-layer stability to theoretically small disturbances. Therefore, for a given stream Mach number and Reynolds number, surface cooling, boundary-layer suction, or a favorable pressure gradient will, in the presence of three-dimensional roughness, promote rather than delay transition.

Report presented at the 13th Meeting of the Flight Test Panel held from 20-25 October 1958 at Copenhagen, Denmark.

There are two techniques currently in use for investigating the flutter characteristics of an aircraft by studying the response of the aircraft to a sinusoidal force input. They are the amplitude response technique and the vectorialANALYSIS TECHNIQUE. Electrodynamic vibrators were utilized for in flight measurement of the response of an aircraft wing to harmonic excitation. Other factors considered for flight flutter testing were structural dynamics, basic excitation, simple harmonic excitation, pulse excitation, airborne instrumentation, data system and analysis, and flight test techniques. (Author)

The paper begins with a review of earlier supersonic design problems, now mostly solved or alleviated; conclusions are drawn from this review, in the light of which the newer problems of heating are then examined. Current experience of temperature as a design parameter is discussed, especially in relation to flight factors, and it is concluded that the solutions to heating problems themselves will not be entirely without relief. New materials, and methods of presenting their properties at high temperature, are also discussed. (Author), NATO Furnished. Presented at the Meeting of the Structures and Materials Panel (8th), held in Copenhagen (Denmark), 20-25 Oct 58.

Many coordinated methods were utilized in the study of the dynamic characteristics of the aircraft Breguet 940. Methods of study included utilization of a fixed model in a wind tunnel, a motorized flying model, an electronic flight simulator, and observations of the aircraft itself in flight., NATO Furnished. Text in French; discussion partly in English; addendum in English.

The influence of the non-linear effects on the flight behaviour of modern high-performance aircraft under control inputs is demonstrated withA NUMBER OF SYSTEMATIC CALCULATIONS. These illustrate the coupling effects with various symmetrical and unsymmetrical control inputs at different Mach numbers and altitudes. In addition, the effects of changing the aerodynamic derivatives, of the engine gyroscopic couple, and of the ratio of moments of inertia are demonstrated. (Author)

The estimation of subsonic rotary stability derivatives of wings is treated. The unsteady potential flow problem is solved by a superposition of steady-flow solutions. Numerical results for the damping coefficients of triangular wings are presented as functions of aspect ratio and Mach number, and are compared with experimental results over the Mach number range 0 to 1. Experimental results are used to point out a close correlation between the non-linear variations with angle of attack of the static pitchingmoment curve slope and the damping-in-pitch coefficient. The underlying basis for the correlation is found as a result of an analysis in which the indicial function concept and the principle of superposition are adapted to apply to the non-linear problem. The form of the result suggests a method of estimating non-linear damping coefficients from results of static wind-tunnel measurements. (Author)

BILITY OF HIS FLOW HAS NOT YET BEEN FULLY INVESTIGATED. The analysis sho s t i is possibl however, o obtain an exact solution for thi tability probl , a uch a solution is developed. (Aut or)

The over-all organization, facilities and methods used by the U.S. Navy to test and evaluate aircraft weapon systems are described as follows: (1) The birth of a Naval aircraft weapon system; (2) The concept of Navy testing; (3) The Navy's testing organization; (4) A chronology of the tests; and (5) Management of the tests. Detail test procedures are not discussed, but these conform to normal practice. (Author)

A method for calculating the characteristic values of the turbulent boundary layer with suction is given. The method is based on an approximate solution of the momentum- and energy-integral equations of the boundary layer. It is applicable to arbitrary continuous distributions of both potential velocity and suction velocity. The assumptions for the shearing stress at the wall and the turbulen dissipation are taken from the theory of the turbulent boundary layer without suction in a slightly modified form by introducing a not yet specified function of the suction velocity. The calculation yields the momentum thickness and a shape factor which is regarded as a criterion for the position of the point of separation. Soutions in closed form are obtained for the flat plate at zero incidence with homogeneous suction and for boundary layer flows with similar velocity profiles (similar solutions). It is demonstrated by numerical examples that in order to avoid separation on the upper side of an aerofoil it is more economic to concentrate suction on a small region near the pressure minimum than to extend it over a larger area. (Author), This Report is one in the Series 253-284 of papers presented at the Boundary Layer Research Meeting of the AGARD Fluid Dynamics Panel held from 25th to 29th April, 1960, in London, England.

The three-dimensional incompressible flow of fluid along the corner of two semi-infinite plates intersecting at right angles, especially the interference of the boundary layers of the two plates, is discussed. Mainly, the more important case of turbulent boundary layer is treated by means of experimental studies carried out at the Technical University of Braunschweig. Some theoretical results for laminar flow are also taken into account. In order to describe the interference effects in the boundary layer, an interference displacement thickness and an interference skin friction have been introduced. It is shown from experiments and also from theoretical considerations how these two quantities depend on Reynolds number. Furthermore, the influence of interference on the transition from laminar to turbulent flow is investigated. In addition, some preliminary results are given about the effect of the pressure gradient on the interference effects. (Author)

(OVER) CONTENTS: Use and value of the step test for selecting airmen and evaluating their cardiac tolerance to stress; The stool test; Response evaluation in the muscular exercise fitness test and respiratory responses to the stool test; The work electrocardiogram; A test battery for evaluation of the circulatory function during pressure breathing; Blood pressure changes in the Flack test; Experimental research on the calibration of some respiratory and cardiocirculatory functional tests; Calibration in groups of pilots of the main respiratory and cardio-circulatory responses to low barometric pressure; The Stipple test: A follow-up study including notes on hyperventilation; Biophysical and physiological considerations of skin resistance, with special reference to findings in isolation; Recommendations for selection criteria for pilots of NATO air forces.

This AGARDograph describes various flow visualization techniques in current use in British wind tunnel practice which are not dealt with fully elsewhere. Emphasis is on such of these techniques that have been developed during recent years - particularly those devised for the understanding of separated flows. These include two of the most valuable methods for investigating three-dimensional flow; namely, the vapour screen and surface oil flow techniques. Other techniques described are various techniques for locating boundary-layer transition, and smoke techniques for use in lowspeed wind tunnels. Included in the AGARDograph are many References, and also an extensive Bibliography covering the complete range of indicator techniques.

Presented at the Meeting of the Flight Test Panel (13th) 20-25 Oct 58 in Copenhagen (Denmark).

Presented at the Meeting of the Flight Test Panel (13th) 21-25 Oct 58 in Copenhagen (Denmark).

A number of important considerations are discussed in connection with variable-sweep aeroplanes, particularly the question of where the pivot should be located. As well as the main advantages to be gained from matching sweep angle to speed, it also offers some less obvious possibilities of adjusting trim drag and stability, and a new method of lateral control at high sweep angles. (Author), Presented at the Twenty-Second Meeting of the Flight Mechanics Panel, held in Torino, Italy, 16-19 Apr 63.

This paper is an introduction to the problem of defining and selecting an automated data processing system for a wind tunnel facility. The restraints imposed by speed and accuracy requirements, and the characteristics of various facilities and types of testing are discussed. Typical systems and system elements are described. A tabulation listing the present data processing systems for many wind tunnel installations and a sample specification for a modern system are included.

This report reviews the theory of wall pressure fluctuations in incompressible flow, and shows how the character of the pressure fluctuations changes in passing from the flow to the wall. Attention is drawn to the more important interactions giving rise to the pressure fluctuations, as well as to the region of the boundary layer mainly responsible for the wall pressure fluctuations. The work is extended to include the effects of compressibility. It is found that an analysis similar to that of Phillips to appropriate, although, unlike the latter work, this new treatment is not restricted to the case of very high supersonic Mach numbers. The analysis makes use of the ratio a sub w as a large parameter, where a sub w is the speed of sound at the wall and u sub tau is the shear velocity. This is certainly true for a very wide range of Mach numbers provided that the wall is not subjected to large rates of heat transfer. It is shown that the wall pressure fluctuations are now the result of fluctuations in both the vorticity and sound mode. At high Mach numbers, the latter contribution is in the form of eddy Mach waves, as suggested by Phillips. On making certain assumptions regarding the dominant interactions, estimates of the magnitude and spectrum of the wall pressure fluctuations are made which show similar trends to the measurements of Kistler and Chen., Paper presented at the AGARD Specialists' Meeting on 'The Mechanism of Noise Generation in Turbulent Flow' held at the Training Center for Experimental Aerodynamics, Rhode-Sait-Genese, Belgium, 1-5 Apr 1963.

By using a photomultiplier and cathode-ray oscillograph responsive only to changes in light signal, the sodium-line reversal technique has been adapted for time-resolved studies of temperature behind shock waves produced by a bursting diaphragm. A double-beam system has also been developed, which eliminates changes due to varying concentration of added metal, and interference filters can be used instead of a spectrograph. General agreement between calculated and observed temperatures is obtained, but both air and oxygen show a high-temperature region due to burning at the interface with the hydrogen driver gas. In nitrogen around 2400 K, a low temperature region close to the shock front may be attributed to a vibrational energy lag of the order of 100 microseconds, the sodium excitation following the effective vibrational temperature rather than the translational temperature of the nitrogen. In oxygen, evidence for a dissociation relaxation effect is obtained for shocks, giving temperatures of around 2500 K; this produces an abnormally high temperature near the front.