Deutsche Aerospace. Das Geschaeftsjahr 1991

Dem Bericht des Aufsichtsrats- und des Vorstandsvorsitzenden folgt ein ausfuehrlicher, reich illustrierter Lagebericht. Eingegangen wird darin u.a. auf ruecklaeufige Tendenzen in der Luft- und Raumfahrtindustrie, auf die neue Fuehrungsstruktur in der Deutschen Aerospace und auf die Ausweitung internationaler Kooperationen. Der Konzernumsatz hielt sich auf Vorjahreshoehe. Der Belegschaftsstand im DASA-Konzern betraegt derzeit 56.000 Mitarbeiter. Anschliessend werden Umsatz, Auslandsanteil und Beschaeftigtenzahl sowie Entwicklungsschwerpunkte in der Luft- und Raumfahrt sowie der Verteidigung und der zivilen Systeme sowie andere Aktivitaeten der Konzernunternehmen wie Dornier, MBB, MTU und TST aufgezeigt. Abschliessend wird ueber die Jahresabschluesse ein umfangreiches Tabellenmaterial vorgelegt. (HWJ)The reports by the respective chairmen of the Supervisory Board and the Board of Management are followed by a very detailed and illustrated report on the state of the concern. It examines the reverse trends in the aerospace industry, the new managerial structure at Deutsche Aerospace and the widening of international cooperation. The concern recorded the same turnover as it had achieved in the previous year. DASA currently employs a staff of 56,000. The report then outlines turnover figures, percentages recorded in operations abroad, numbers of employees and core areas of development in aviation and space travel, defence, civil systems and in the concern's other spheres of involvement, for example Dornier, MBB, MTU and TST. Extensive tabular data is finally presented detailing the concern's end-of-year figures. (HWJ)SIGLEAvailable from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Detonation profiles in HE-charges with longitudinal gaps

Precursor air shocks with velocities that are 50% higher than the velocity of detonation occur not only in cylindrical holes, but also in flat slits. By attaching to the test charge a sufficiently long plexiglass body with the same hole or slit profiles it is possible to observe the end face of the test charge and, thus, to record the changes in the detonation profile caused by slits, in particular by such that are oblique to the direction of detonation. One result is, that there is no through-detonation across thin slits that are at a flat angle to the detonation wave. (orig.)Available from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Heliradar - a synthetic aperture radar with rotating antennas

Nowadays available radar instruments are not capable to guide a helicopter pilot safely during approach and landing under poor visibility conditions. This is due to lack of resolution and lack of elevation (height) information. The basic technology that could be used to improve the radar significantly is the ROSAR technology, a synthetic aperture radar based on rotating antennas. On the basis of encourating research work on the ROSAR technology, Eurocopter Deutschland (ECD) started in 1992 a research program to investigate the feasibility of a ROSAR based imaging radar: HeliRadar. The objective of HeliRadar is to provide a photolike image whose resolution is good enough to safely guide a pilot under poor visibility conditions to the target destination. (orig.)Available from TIB Hannover: RR 2088(33-93 PUB)ME / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Instability suppression mechanisms

One of the major technical issues in the development of liquid propellant rocket engines is the high frequency combustion instability, which is the most destructive kind of instability and the hardest to control. The most successfully used suppression mechanisms are baffles and quarterwave as well as Helmholtz resonators. For the first lay-out these damping devices acoustical tests with full scale chamber models were performed under ambient conditions with the aim, to gain information regarding the efficiency of various types of resonators. With the theory shown in this paper and empirical values of comparable engines these results are transfered to hot gas conditions. Then the hot gas tests in the original engine are taken to varify the first lay-out and to improve the accuracy of the tuning if necessary. In this paper special emphasis was given first to t orifice shapes of the resonators, to make an impedance adaptation between the resonators and the combustion chamber to receive a high absorption coefficient and second to nonlinear effects due to high sound pressure levels. Transfer function measurements between cavity and chamber dynamic pressure during hot tests gave more precise data regarding cavity resonances and impedances. It can be shown in this study, that the lay-out of quarterwave is more predictable as for Helmholtz resonators because the #lambda#/4-resonators are less sensitive to pressure variations. The numerical and the test results indicate, that baffles and resonators can effectively suppress pressure oscillations in the combustion chambers. (orig.)SIGLEAvailable from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Computer aided optimization of circular corrugated horns

The paper describes two different concepts for a computer aided design optimization of circular corrugated horms. Both methods combine a well proven analysis routine by Kuehn und Hombach (Ref. 1) based on mode matching techniques and a sequential quadratic programming (SQP) routine by Schittkowski (Ref. 2) for the minimization of non linear problems. Starting with an initial horn geometry each of the resulting computer algorithms synthesizes the geometry of the optimized horn design. Both methods are briefly discussed, and a classification of different horn types (i.e. axially or radially corrugated horms), for which the one or the other method should be selected, is given. Both methods have been successfully applied for the optimization of various corrugated horn types e.g. the feed horns of the two INTELSAT VIII Ku-Band Spot Beam Antennas, the INTELAST VIII C-Band Global Coverage Antennas, feed horns for DASA's compensated compact antenna test range, and feed horns for different Earth stations, taking into account mechanical and manufacturing aspects as additional optimization restrictions. A considerable reduction of time and man power for the horn optimization was achieved, and the resulting horn designs fulfilled the electrical and mechanical requirements with sufficient margin. (orig.)SIGLEAvailable from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Overview on microsystems technology MST-CAD/CAE - overview and requirements

The definition of microsystems is followed by examples of microsystems technology. In conclusion, technologies for the production of microsystems are explained. Research programs from the U.S.A., Germany, and Europe are briefly outlined. (CT)Available from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

MOMS-02 auf D2 Endbericht

Remote sensing of the earth, with the branch of land observation, is a component of the 4th Space Program of the Federal Republic of Germany. The national activities are complementary to ESA's European Earth Observation Program, to which the Federal Republic makes a considerable contribution. The activities promoted under this program comprise preliminary scientific and technological studies, the development of new satellite carried instruments and the execution of pilot projects to demonstrate and broaden the geoscientific utilization of instruments. Within this framework, MBB has been promoting instrument development of the Modular Optoelectronic Multispectral Scanner MOMS for land observation within the optical spectrum since 1976. One basic concept of the MOMS development line, pursued from the beginning, is that of a far-reaching modularity to permit a considerable reduction of the effort involved as compared to similar instruments, in order to achieve an extension toward more and narrower spectral channels and toward stereoscopic imaging techniques. For these purposes, MOMS-02 on Spacelab D-2 was a logical continuation of this development line. (orig.)SIGLEAvailable from TIB Hannover: F95B1918+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany); Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA) GmbH, Bonn (Germany)DEGerman

Configuration and program status of Eurocopter's new light twin helicopter EC135

In October 1988 the first flight of the BO108 VT01 took place. This helicopter has been used as a flying test bed to verify the characteristics and performances of the main systems. More than 250 h has been flown with the VT01. Several presentations have been given with regard to development of main systems [1], used technologies [2] or test results [3]. In June 1991 the second prototype VT02 joined the test program. This h/c was for the first time equipped with a FADEC controlled engine (TM 319-1B). Beside fine tuning of the main systems the primary task for VT02 was to develop the engine interfaces and engine control for serial production. In autumn 1991 an actualized market survey led to different requirements. Especially the need for more seating capacity was clearly recommended. In addition with the merge of Aerospatiale's and MBB's Helicopter Divisions the full range of AS technology has been made available for this helicopter. Eurocopters new light twin helicopter - now called EC135 - is the evolution of the BO 108 but with - increased seating capacity without changing the outer dimensions drastically; - a completely new designed Fan-in-Fin anti torque system; - new designed main transmission in terms of housing material and height; - an improved low noise concept' - an improved BMR. Special attention was given to the production cost in order to offer the customer an attractive aquistition price. So the 'Design to Cost Principle' had been fully applied during the redesign phase. The EC135 program foresees the use of two preproduction aircrafts with first flights in February 1994 (S01 with TM 319-2B) and April 1994 (S02 with PW 206B) for the certification. Design freeze is planned in the second half of 1994, VFR certification in early 1996 and IFR certification in early 1997. The first customer aircraft will be available in mid 1996. (orig.)Available from TIB Hannover: RR 2088(29-93 PUB)ME / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Dreidimensionale Netzgenerierung und Eulerrechnung fuer eine Fluegel-Rumpf-Canard Konfiguration

Under this thesis a three-dimensional multiblock grid was generated for the vortex flow model. The method of grid generation consists essentially of three parts: Preliminary work in a CAD system, DOGRID surface grid generation, and three-dimensional grid generation. The grid was used to perform Euler calculations for the configuration with and without canard. A comparison of calculated results with the measurements of NLR has shown that this method for multiblock generation can be used to simulate the canard's influence on the flow. (orig.)In dieser Diplomarbeit wurde ein dreidimensionales Multiblock-Netz fuer das Vortex Flow Model erzeugt. Das Verfahren zur Netzgenerierung besteht im wesentlichen aus drei Teilen: Den Vorarbeiten in einem CAD-System, der DOGRID-Oberflaechennetzerzeugung und der Raumnetzgenerierung. Mit dem Netz wurden Eulerrechnungen fuer die Konfiguration mit und ohne Canard durchgefuehrt. Ein Vergleich der Rechenergebnisse mit den Messungen der NLR hat gezeigt, dass mit diesem Verfahren zur Multiblock-Netzgenerierung der Einfluss des Canards auf die Stroemung simuliert werden kann. (orig.)Available from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Verallgemeinerung eines Viscous-Shock-Layer Loesungsverfahrens zur Beruecksichtigung dreidimensionaler Effekte in Staupunktnaehe

The solution of viscous shock-layer equations requires a stagnation point approach. Previous approaches have started from a rotationally symmetrical body in the stagnation point region. The objective of the present thesis is to generalize the stagnation point solution in order to be able to cancel the limitation associated with the premise of a rotationally symmetrical flow in the stagnation point. The extension of the stagnation point solution requires a new derivation of the stagnation point equations from locally quasi-two-dimensional viscous shock-layer approaches, permitting calculation of three-dimensional effects in the vicinity of the stagnation point. Averaging the locally quasi-two-dimensional stagnation point solutions results in good starting solutions for ratios of the main radii of curvature in the stagnation point smaller than 1/1.5. These starting solutions are suitable for the calculation of a three-dimensional body. (orig.)Zur Loesung der Viscous-Shock-Layer-Gleichungen ist eine Staupunktloesung erforderlich. Bisherige Ansaetze sind von einem rotationssymmetrischen Koerper im Staupunktbereich ausgegangen. Ziel der vorliegenden Arbeit ist die Verallgemeinerung der Staupunktloesung, damit die Einschraenkung der Voraussetzung einer rotationssymmetrischen Stroemung im Staupunkt aufgehoben werden kann. Die Erweiterung der Staupunktloesung verlangt eine neue Herleitung der Staupunktgleichungen aus lokal quasi-zweidimensionalen Viscous-Shock-Layer-Ansaetzen, die eine Berechnung dreidimensionaler Effekte in Staupunktnaehe ermoeglicht. Eine Mittelung der lokal quasi-zweidimensionalen Staupunktloesungen bringt bei Verhaeltnissen der Hauptkruemmungsradien im Staupunkt die kleiner als 1/1,5 sind, gute Startloesungen. Diese sind zur Berechnung eines dreidimensionalen Koerpers geeignet. (orig.)Available from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman