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Wiener Neustadt, Austria

The University of Applied science Wiener Neustadt is an Austrian Fachhochschule founded in 1994. It has seven areas of specialization. The main campus is in Wiener Neustadt and two smaller campuses are located in Wieselburg and Tulln . The business school also offers a course called "Business Consultancy International", a bachelor degree program, which is exclusively taught in English. Another program taught in English is the "Aerospace Engineering" Master program. Wikipedia.

Krejci D.,Fotec GmbH | Woschnak A.,Fotec GmbH | Scharlemann C.,University of Applied Sciences Wiener Neustadt | Ponweiser K.,Vienna University of Technology
Chemical Engineering Research and Design | Year: 2012

Hydrogen peroxide is under investigation with regard to its potential to replace the presently used highly toxic rocket propellants NTO and MON-3. Catalytically decomposed hydrogen peroxide results in a steam-oxygen mixture at elevated temperature and can be used either as a monopropellant or as an oxidizer in a bipropellant system. To guide the monolith catalyst design, a lumped parameter model of the decomposition implemented into a numerical thermal model has been developed. The one dimensional flow model includes decomposition and is coupled to a finite element structural domain of the decomposition chamber and catalyst to investigate the impact of the catalyst and the chamber structure on the decomposition behavior. Special focus is laid on the transitional behavior of hydrogen peroxide conversion to facilitate immediate start-up of the thruster system after valve opening command. The numerical results have been validated with experimental data. Major findings of the model such as the existence of a radial temperature gradient across the catalyst have been experimentally validated. The presented theoretical method predicted a strong impact of structural mass capacities of catalyst and decomposition chamber on the transient decomposition performance. This prediction has shown to be in good correlation with the experimental results. © 2012 The Institution of Chemical Engineers. Source

Scharlemann C.,University of Applied Sciences Wiener Neustadt
47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2011 | Year: 2011

The possibility of replacing presently used highly toxic propellants by so-called Green Propellants has captured the attention of research groups as well as of the relevant industry worldwide. And indeed the potential of Green Propellants seems inspiring. The lower level of toxicity reduces the risk for personnel handling such propellants and therefore allows simplified and more cost efficient handling procedures. A variety of authors have outlined other areas of possible cost reduction when using propellants with a lower toxicity level. This includes a simplification of the propellant logistic and storage, fueling infrastructures at the launch pads, and propellant procurement to name only some. Most authors have focused on one particular Green Propellant in their experimental work and outlined the characteristics and benefits of it. Although very promising results have been reported, Green Propellants in general have up to now failed to generate a confidence level sufficient for the major industry to initiate first steps to implement them into a commercially available propulsion system. Contributing to this hesitation is the lack of a comprehensive effort to investigate Green Propellants and to provide industry with information they can use to re-evaluate their future strategy in respect to Green Propellants. For this reason a European consortium, financed by the European Commission in the 7th Framework Program (FP7) and consisting of 11 entities from 7 European countries, was established. The project, "Green Advanced Space Propulsion" (GRASP) aspires to provide such an information background. In the first phase of the project, GRASP has compiled a data base of more than 100 Green Propellant. This data base contains physical properties as well as information with regard to the individual toxicity levels and performance data. Based on this data base a preliminary selection was conducted to identify the most promising Green Propellant candidates. In the present phase of the project those candidate propellants are experimentally investigated to further down-select the candidates. The present paper provides an overview of the GRASP activities and discusses the selection process and the GRASP objectives in general and test goals obtained up to now in particular. © 2011 by Carsten Scharlemann. Source

Hochrainer M.J.,University of Applied Sciences Wiener Neustadt
Conference Proceedings of the Society for Experimental Mechanics Series | Year: 2015

Tuned liquid column gas damper (TLCGD) show excellent vibration absorbing capabilities appropriate for applications in wind- and earthquake engineering. However, in the early regime of strong motion seismic excitation or to counteract strong wind gusts the performance of the passive device can be increased substantially by active elements obtained from adding a pressurized gas supply with input-output valves to the sealed ends of the TLCGD. To prove the working principle of active TLCGD several small scale laboratory experiments have been performed with single and multiple degree of freedom host structures. To obtain a desired dynamic behavior, a conventional feedback control law is used to compute small active pressure inputs to the TLCGD. The experiments have proven that the active device is able to substantially reduce the dynamic system response in a broad frequency range. In fact, dangerous structural resonances of lightly damped structures can be avoided even if the passive absorber is not tuned perfectly. For multiple degree of freedom host structures a suitable control enables a single active TLCGD to counteract several modes of vibrations thereby avoiding the need to install numerous passive devices. © The Society for Experimental Mechanics, Inc. 2015. Source

Hochrainer M.J.,University of Applied Sciences Wiener Neustadt
Sound and Vibration | Year: 2014

The visualization of structural vibrations has always been a key technology when teaching vibration analysis. If the structural motion can be perceived directly without numerical simulation or extensive measurements, basic modal analysis concepts like mode shapes, natural frequencies or resonances and antiresonances are intuitively understood. The application of stroboscopes has a long tradition in vibration analysis and is particularly well established in rotor dynamics. Nevertheless an inexpensive and simple device for the visualization of larger structures like car spoilers was missing. The application of several arrays of white-light, high-power, light-emitting diodes together with an electronic power supply resulted in an innovative and highly flexible distributed light source perfectly suited to visualize resonant structural vibrations in the mid-frequency range. Furthermore, the effect of aliasing is demonstrated convincingly and the results can be compared qualitatively to experimental modal analysis. In combination with an electrodynamic shaker, the setup has been applied successfully to visualize vibrations of parts of car bodies, tennis racquets, skis, piano or cello strings, as well as plate and shell structures. Source

Murin J.,Slovak University of Technology in Bratislava | Aminbaghai M.,Vienna University of Technology | Hrabovsky J.,Slovak University of Technology in Bratislava | Kutis V.,Slovak University of Technology in Bratislava | Kugler S.,University of Applied Sciences Wiener Neustadt
Composites Part B: Engineering | Year: 2013

In the proposed contribution the effect of the shear correction function is originally studied and evaluated in modal analysis of the functionally graded material (FGM) beams. Spatially continuous variations of the material properties are considered. The shear correction function is calculated from the shear strain energy equation including spatial Poisson′s ratio variations. The equations of the homogenized FGM beam free vibration and their solution is presented including the shear correction function. Four coupled differential equations are derived and used in the modal analysis of beams with polynomial continuous longitudinal and transversal variations of material properties. Further, 2nd order beam effects and longitudinal varying elastic beam foundations are considered. The influence of using an average shear correction factor is evaluated through numerical experiments. Additionally, the longitudinal eigenfrequencies are calculated. Continuum solutions using solid finite elements are taken as a reference for comparison purposes. © 2012 Elsevier Ltd. All rights reserved. Source

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