Airbus - ein gelungenes Beispiel für beschäftigungsorientierte Industriepolitik?

Spätestens seit dem offiziellen Verkaufsstart des A3XX am 23.6.2000 ist der Airbus wieder in aller Munde. Am selben Tag wurde die Überführung des Konsortiums in eine eigenständige Aktiengesellschaft nach französischem Recht bekanntgegeben. Zusammen mit der Fusion drei der vier Airbus-Mutter-Unternehmen (Aerospatiale Matra,Casa und DASA) zum neuen europäischen Luft- und Raumfahrtunternehmen EADS und dem Börsengang am 1O.7.2llllll ist eine Entwicklung zum vorläufigen Abschluß gekommen, die in den 60er Jahren begann. Ziel war es damals gewesen, den Rückstand Europas gegenüber den USA im zivilen Großflugzeugbau aufzuholen. Es sollte die vermutete technologische Lücke geschlossen werden. Die Luftfahrtindustrie wurde als strategische Zukunftsbranche betrachtet: zum einen wegen der militärischen Relevanz, zum anderen wegen dem Rückstand gegenüber den USA. Nicht zuletzt erhoffte man sich die Schaffung von Arbeitsplätzen in einem zukunftsorientierten Bereich, ein Anliegen, das seit den 80er und 90er Jahren des vergangeneu Jahrhunderts auf Grund der verschärften Arbeitsmarktprobleme in Europa an Bedeutung hinzugewonnen hat. Aus diesen Grunden wurden erhebliche öffentliche Mittel in die Unterstützung der Entwicklung neuer Flugzeuge investiert. Das Airbus-Projekt wurde zu einem der größten Subventionsempfänger in Europa. Aus theoretischer Sicht wurde der Airbus zu einem klassischen Fall vertikaler (das heißt, sektoraler, auf einzelne Branchen bezogener) Industriepolitik, zu deren Rechtfertigung Elemente der Theorie der Strategischen Handelspolitik herangezogen wurden. Er eignet sich deshalb besonders gut für eine an industriepolitischen Fragestellungen interessierten Untersuchung. Aus dem Gesagten ergibt sich die Vergebensweise der vorliegenden Untersuchung. Im ersten Schritt ist die historische Entwicklung des Airbus nachzuzeichnen. Im zweiten Schritt wird die Praxis der theoretischen Überprüfung unterzogen: Durch welche Charakteristika ist die Produktion ziviler Großraumflugzeuge gekennzeichnet? Welche staatlichen Handlungsoptionen lassen sich daraus vor dem Hintergrund der Theorie der strategischen Handelspolitik ableiten? Welche Ergebnisse empirischer Studien liegen vor Danach sind die Beschäftigungswirkungen zu analysieren. Im letzten Abschnitt werden die Ergebnisse zusammengefasst. --

Investigation of passive flow control techniques to enhance the stall characteristics of a microlight aircraft

This report investigates the enhancement of aerodynamic stall characteristics of a Skyranger microlight aircraft by the use of passive flow control techniques, namely vortex generators and turbulators. Each flow control device is designed and scaled to application conditions. Force balance measurements and surface oil flow visualisation are carried out on a half-model of the microlight to further investigate the nature of the flow on the aircraft with and without the flow control devices. The results indicate a clear advantage to the use of turbulators compared with vortex generators. Turbulators increased the maximum lift coefficient by 2.8%, delayed the onset of stall by increasing the critical angle by 17.6% and reduced the drag penalty at both lower (pre-stall) and higher angles of attack by 8% compared to vortex generators. With vortex generators applied, the results indicated a delayed stall with an increase in the critical angle by 2% and a reduced drag penalty at higher angles of attack

A Simple Method for High-Lift Propeller Conceptual Design

In this paper, we present a simple method for designing propellers that are placed upstream of the leading edge of a wing in order to augment lift. Because the primary purpose of these "high-lift propellers" is to increase lift rather than produce thrust, these props are best viewed as a form of high-lift device; consequently, they should be designed differently than traditional propellers. We present a theory that describes how these props can be designed to provide a relatively uniform axial velocity increase, which is hypothesized to be advantageous for lift augmentation based on a literature survey. Computational modeling indicates that such propellers can generate the same average induced axial velocity while consuming less power and producing less thrust than conventional propeller designs. For an example problem based on specifications for NASA's Scalable Convergent Electric Propulsion Technology and Operations Research (SCEPTOR) flight demonstrator, a propeller designed with the new method requires approximately 15% less power and produces approximately 11% less thrust than one designed for minimum induced loss. Higher-order modeling and/or wind tunnel testing are needed to verify the predicted performance

Aerodynamic and Aeroacoustic Performance of Small UAV Propellers in Static Conditions

The proliferation of small multi-rotor UAVs in commercial, recreational, and surveillance spheres has garnered significant interest in the noise produced by these vehicles. The current research aims to study the relationship between the aerodynamic performance and acoustic characteristics of small-scale UAV propellers. Three commercially available propellers for the DJI Phantom 2/3 UAV were selected for preliminary development and validation of an aeroacoustic experimental test setup and associated data reduction methods. Propeller thrust, torque, and power measurements were recorded at static conditions. Upon successful validation of the test bench, acoustic measurements were taken at the propeller disk’s upstream and in-plane locations. The power spectral density of these acoustic signals was estimated using the modified periodogram (Welch’s) method to identify frequency content and calculate sound pressure levels (SPLs) at each of the observation locations. Additionally, time-frequency analysis verified the periodogram results and identified possible sources of transient noise at static thrust. These methods found the nonrotor noise to be a major contributor to the SPL at higher frequencies and the propeller noise dominating the SPL spectra at the lower frequencies. Experimental thrust, torque, power, and sound pressure level (SPL) data were then compared for each propeller to identify relationships between aerodynamic performance and acoustic characteristics with variations in propeller geometry and blade loading

Preliminary noise assessment of aircraft with distributed electric propulsion

Electric and hybrid-electric propulsion technologies in aviation are becoming more attractive for aviation stakeholders not only due to the resulting reduction or elimination of the dependency on oil, whose availability and price are uncertain, but also because they are more reliable and efficient than traditional internal combustion engines. Moreover, combined with distributed electric propulsion (DEP), these technologies have shown potential in significantly reducing civil aircraft community noise impact and contribute towards delivering the strict mid-to-long-term environmental goals set by organisations worldwide, such as ACARE and NASA. This paper examines the noise impact of a concept tube and wing aircraft that falls in the A320 category and features various DEP systems using different power supply units (turboshaft engines or batteries) and number of electric propulsors. Meanwhile, considerations required for the transition from conventional to electric propulsion are discussed. Estimated Noise-Power-Distance (NPD) curves and noise exposure contour maps are also presented. It is concluded that indeed, the propulsors’ number is a key parameter for optimising the environmental performance of DEP aircraft and hence maximising the noise benefits. Also, it is shown that based on the entry into service year (2035) technology, totally electric aircraft tend to have a larger noise footprint than aircraft using hybrid electric propulsion systems

Static Testing of Propulsion Elements for Small Multirotor Unmanned Aerial Vehicles

The growing use of small multirotor aircraft has increased the interest in having better performance results especially with the propulsion system. The size of the propellers used on these aircraft operate at low Reynolds numbers that are typically less than 200,000. Static performance testing of ten propeller pairs (tractor and pusher) were completed and is the beginning of a systematic test of propellers used on multirotor systems. The propellers chosen for this initial set of tests were selected from four popular quadrotors. Besides testing the propellers provided with the aircraft, propellers that are sold as replacements from third-party companies were also tested. Both the 3D Robotics Solo and DJI Phantom 3 had multiple propellers tested and a method to compare the resulting endurance is discussed

Internal Transcribed Spacer 2 (nu ITS2 rRNA) Sequence-Structure Phylogenetics: Towards an Automated Reconstruction of the Green Algal Tree of Life

L). Some have advocated the use of the nuclear-encoded, internal transcribed spacer two (ITS2) as an alternative to the traditional chloroplast markers. However, the ITS2 is broadly perceived to be insufficiently conserved or to be confounded by introgression or biparental inheritance patterns, precluding its broad use in phylogenetic reconstruction or as a DNA barcode. A growing body of evidence has shown that simultaneous analysis of nucleotide data with secondary structure information can overcome at least some of the limitations of ITS2. The goal of this investigation was to assess the feasibility of an automated, sequence-structure approach for analysis of IT2 data from a large sampling of phylum Chlorophyta.Sequences and secondary structures from 591 chlorophycean, 741 trebouxiophycean and 938 ulvophycean algae, all obtained from the ITS2 Database, were aligned using a sequence structure-specific scoring matrix. Phylogenetic relationships were reconstructed by Profile Neighbor-Joining coupled with a sequence structure-specific, general time reversible substitution model. Results from analyses of the ITS2 data were robust at multiple nodes and showed considerable congruence with results from published phylogenetic analyses.Our observations on the power of automated, sequence-structure analyses of ITS2 to reconstruct phylum-level phylogenies of the green algae validate this approach to assessing diversity for large sets of chlorophytan taxa. Moreover, our results indicate that objections to the use of ITS2 for DNA barcoding should be weighed against the utility of an automated, data analysis approach with demonstrated power to reconstruct evolutionary patterns for highly divergent lineages

Governance im Politikfeld Wirtschaftspolitik

This paper gives an overview of the topic "economic governance". This term is used in economics and neighboring social sciences as a generic term under which usually all activities are subsumed that are conducted by economic policymakers to 'steer' or 'control' the economic system, individual markets therein or certain economic actors (e.g., businesses, consumers). In addition to a more detailed clarification of the concept of "economic governance" and the presentation of actors and instruments of economic governance, the paper discusses why and in what situations economic governance is necessary. The latter issue is the subject of a continuing debate in politics, the public and the social sciences