Comparison of two acoustic analogies applied to experimental PIV data for cavity sound emission estimation

The aim of the present study is to compare two different acoustic analogies applied to time-resolved particle image velocimetry (PIV) data for the prediction of the acoustic far-field generated by the flow over a rectangular cavity. Recent developments in laser and camera technology allow the possibility to extend PIV to the study of aeroacoustic phenomena in air flows at moderate speed (up to V=20m/s, Ma=0.08). We make use of these new possibilities to obtain estimates of the acoustic emission from time-resolved PIV data. We consider the model problem of the sound radiating from an open, two dimensional, shallow cavity with an aspect ratio between its length and depth of 2 at a Reynolds number of 3:0£104 based on the cavity length. The study is carried out combining high speed two dimensional PIV imaging and sound measurements. The emitted sound is then calculated using Curle’s analogy and vortex sound theory. The prediction of the acoustic fields obtained by applying the two methods are analyzed and compared with the measured sound. Results show that both the analogies estimate the overall sound pressure level quite well and within a few dB of each other. Vortex sound theory seems to provide a better estimate for the amplitude of the tonal component and its harmonics, but suffers from higher broadband noise compare to Curle’s analogy. This is due to the higher smoothing of the data involved in the computation of the source term in Curle’s analogy, which reduces noise but also smoothes out the signal. Results show that great care must be taken in the treatment of the experimental PIV data, especially in the techniques used for spatial and temporal differentiation. The data sets obtained by PIV measurements can be, in fact, quite noisy while the spatial and temporal resolution are still limited.Process and EnergyMechanical, Maritime and Materials Engineerin

Which Side of the Coin? The Regional Governance of Science and Innovation

Koschatzky K., Kroll H. (2007) Which side of the coin? The regional governance of science and innovation, Regional Studies 41, 1115-1127. The paper deals with the impact of recent trends in the devolution of political powers in science, technology and innovation policies. It argues that some problems are associated with this regionalization because the emerging multi-level governance structures turn political action into a complex bargaining process between actor groups with partially conflicting interests. The paper sketches the theoretical potentials and limitations of science, technology and innovation policy designed at the regional level. Based on regional evidence from the German federal system, it demonstrates which policy aspects are suitable for devolution to regional governments and how they can be integrated in multi-level governance structures. Koschatzky K. et Kroll H. (2007) Quelle facette du probleme? La gouvernance reginale de la science et de l'innovation, Regional Studies 41, 1115-1127. Cet article cherche a traiter de l'impact des tendances recentes a la regionalisation des pouvoirs politiques dans le domaine des politiques en faveur de la science, de la technologie et de l'innovation. On affirme qu'un certain nombre de probleemes se rapportent a cette regionalisation parce que les structures de gouvernance a plusieurs niveaux naissantes peuvent transformet l'action politique en un processus de negociation complexe entre des groupes d'acteurs dont les interets sont en partie contradictoires. Cet article esquisse done le potentiel et la limite theoriques de la politique de science, de technologie et d'innovation elanoree sur le plan regional. A Partir des preuves provenant du systeme federal allemand, on presente les aspects de la politique qui se preent bien a leur transfer aux instances reegionles et comment ils peuvent s'integrer dans des structures de gouvernance a plusieurs niveaux. Govuvernance regionale Politique des science Intelligence strategique Gouvernance a plusieurs niveaux Systeme federal Bremes. Koschatzky K. und Kroll H. (2007) Which side of the coin? The regional governance of science and innovation, Regional Studies 41, 1115-1127. Der Beitrag befasst sich mit der Bedeutung der Dezentralisierung politischer Entscheidungsbefugnisse in der Wissenschafts-, Technologie- und Innovationspolitik, in dem er sich mit den Problemen und Chancen dieser Regionalisierung auseinander setzt. Es wird die These vertreten, dass durch die Multi-Ebenen-Governance Strukturen politisches Handeln zunehmend zu einem komplexen Aushandlungsprozess zwischen den beteiligten Akteursgruppen mit teilweise konfligierenden Interessen wird. Vor diesem Hintergrund umreisst der Beitrag die theoretischen Potenziale und Grenzen von auf der regionalen Ebene gestalteter Wissenschafts-, Technologie- und Innovationspolitik. Basierend auf regionalen Beispielen aus dem deutschen foderalen System zeigt das Papier auf, welche Politikmassnahmen geeignet fur die Ubertragung an regionale Regierungen sind und wie sie in die Multi-Ebenen-Governance Strukturen integriert werden konnen. Regionale Governance Wissenschaftspolitik Strategische Intelligenz Multi-Ebenen-Governance Foderales System Bremen. Koschatzky K. y Kroll H. (2007) �Que cara de la moneda? El gobierno regional de la ciencia y la innovacion, Regional Studies 41, 1115-1127. En este ensayo abordamos la repercusion de tendencias recientes en la transferencia de competencias en las politicas cientificas, tecnologicas y de innovacion. Sostenemos que esta regionalizacion causa numerosos problemas debido a que las nuevas estructuras gubernamentales multinivel convierten las medidas politicas en un complejo proceso de regateo entre los grupos protagonistas con intereses parcialmente conflictivos. Aqui resenamos las limitaciones y el potencial teoricos de las politicas cientifica, tecnologica y la innovacion disenadas en un nivel regional. Basandonos en ejemplos regionales del sistema federal de Alemania, demostramos que aspectos politicos son adecuados para la transferencia de competencias en gobiernos regionales y como pueden ser integrados en estructuras de gobiernos multinivel. Gobierno regional Politica cientifica Inteligencia estrategica Gobierno multinivel Sistema federal BremenRegional governance, Science policy, Strategic intelligence, Multi-level governance, Federal system, Bremen,

Potentialanalyse für Auftragsforschung in der Biotechnologie. Endbericht

Systematic information on R&D-activities in biotechnology has not been available so far. On this background the role of applied R&D in biotechnology has been analyzed for Germany based on an extensive survey of industrial activities. Biotechnology turned out to be very R&D intensive with the respective spendings ranging between 15 and 17% of turnover. Industrial R&D-activities are focussing mainly on pharmaceuticals, environmental applications, development of new methods and process engineering. R&D cooperations between industry and universities are an important feature of biotechnological R&D. Estimates for overal spendings for R&D are presented

Potentialanalyse fuer Auftragsforschung in der Biotechnologie Endbericht

This project was dedicated to the preparation of a biotechnological R and D 'research map' for the Federal Republic of Germany, and to the assessment of the future demand of German firms for institute contract research capacities with regard to the integration of the R and D institutions in the new Lands into a new general concept. The survey, the research results and questionaires are documented. (orig./RHM)Im Rahmen des vorliegenden Vorhabens wurde eine Forschungslandkarte zur biotechnologischen Forschung und Entwicklung (FuE) in der Bundesrepublik erstellt und der zukuenftige Bedarf deutscher Unternehmen an Vertragsforschungskapazitaeten entsprechender Institute ermittelt. Im Hintergrund der Befragung stand dabei auch die Integration der FuE-Institutionen der neuen Bundeslaender in ein neues Gesamtkonzept. Forschungsergebnisse und Fragebogen werden dokumentiert. (orig./RHM)SIGLEAvailable from TIB Hannover: F93B1408+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman