Redbull hangár

Redbull hangár

2011. december 19., hétfő

House of applied science - Visit at Joanneum university’s aviation department

IV. part - The youngest generation of teachers

Text and photos: Gabriella

Simon Jauk and Andreas Tramposch may represent the youngest generation of teachers at Joanneum’s aviation department. They got their diploma here in 2008 and since that time they have been employed as research assistants.  They spoke about their most recent research projects and told their view about the future of aviation. (Although I’m planned to publish in this part the interview with my friend Joachim too, who is studying here, but taking its length, I decided to post it separately in the next part.)

Simon Jauk and Andreas Tramposch at the icing facility

Gabriella: As I heard, there are several research projects going on at the university´s aviation department. Could you mention some of them?

Andreas Tramposch: As an academic staff member of the working group Fluid Dynamics and Heat Transfer, I can mention some research projects located in this field. The Objectivity, one of our projects in cooperation with our project partner AIRBUS, was about the investigation of methods to determine the mixing behavior of different airstreams in a mixer manifold, which is one part of the air conditioning system of passenger aircrafts.
Within this investigation we designed a scaled mock-up model of the mixer manifold and operated a test bench to execute detailed experimental measurements. Additionally, we performed numerical fluid dynamics simulations with the aim of finding a proper turbulence model for a good resolving of the flow structure, but by reducing the calculation effort as much as possible.

G: When did the project start?
AT: In 2009, and it ended about half a year ago.

G: Was this project paid by AIRBUS?
AT: No, it was financed by the FFG, a national research booster of the Austrian Government. AIRBUS provided us the data and information that we needed for the research.

G: If it was financed by Austria, what was the real purpose of the project? Which fields could you mention, where the results will be used?
AT: The aim of such national research projects is that companies or academic institutions –such as the FH JOANNEUM– could gain knowledge in a special research field in Austria.
In detail, spoken for the FH JOANNEUM, these projects allow us to operate and continue modifying our test facilities –for example our own closed icing wind tunnel which we use in some of our other projects. With the aid of the financing we also have the resources to employ academic staff and to ensure the continuation of the operation and the extension of our high performance computing laboratory, which currently consists of 16 quad-core work stations.

G: Could you summarize the results of this project?
AT: Of course, the investigations show that the mixing quality of the mixer unit can be determined successfully with an especially developed carbon dioxide tracer gas method. An advantage of this tracer gas method is, besides low expenses and high flexibility, that there is no need of optical access to the mixer unit which would be necessary for some other measurement methods.
Modifications, for example additional turbulence grids in the pre-mixer, can influence the air jets and possibly lead to a better mixing behavior. With the described tracer gas measurements, the influences of such modifications on the mixing quality can be examined experimentally in a fast way.
The comparisons between measurement data and simulation results carried out within this investigation show that the application of a special scale adaptive simulation turbulence model is in good agreement with the experimental results.

G: Do you know if AIRBUS or any other companies already use this solution?
AT: The gained research results could be used by AIRBUS during the preliminary design phase of the mixer unit.  By using the proposed turbulence model, as well the tracer gas method, the efficiency of the air conditioning system could be improved.

G: Do you think that the passengers will notice this?
AT: Passengers may notice this improvement in the form of a higher comfort feeling inside the passenger cabin.

Problems caused by icing – and the modern solutions

G: Could you speak about the ongoing projects?
AT: Some of our ongoing projects deal with the icing of aircraft components.
During the climb and landing phase airplanes may pass through clouds which contain subcooled water droplets. Because of missing condensation nucleus these water droplets maintain liquid at subfreezing temperatures and freeze immediately when they impact on the airplane. This leads to a very fast ice growing process and represents therefore an especially dangerous scenario in aviation.
Nowadays, several anti-icing and de-icing systems are used to prevent the icing and its problematic consequences. Together with our research partners we are investigating some innovative anti-icing and de-icing systems. For example, in cooperation with the Austrian Research Center we have tested special coatings with hydrophobic properties which should prevent the accretion of water droplets. With our project partner Profactor we tested a de-icing system making use of the inverse piezo effect which leads to a material deformation after applying a certain voltage. If a high frequent change in voltage is used, test objects like airfoils vibrate at high frequency as well and the already existing ice will be removed. Other ongoing investigations concern the testing of a conductive coating developed by Villinger GmbH which gets hot after applying a certain voltage.

G: Do you think that this can prevent the icing of the pitot tube (outer sensor which transfers air data to the board computer), too, which also can cause accidents?
AT: Especially the conductive coating is very promising because of its flexible application and could also be used to prevent pitot tube icing. But also the existing anti-icing systems will prevent most icing accidents. Most of the icing accidents are still caused by human failure.

G: Is there a dedicated time for this project?
AT: Two years. We are in its second year.

Simon Jauk is explaining the operation of the flight simulator

Effective air cargo, alternative fuels

G: Are there more projects which you would like to mention?
Simon Jauk: Yes, for example the sCAT project, which was already finished in March. sCAT stands for small cargo air transporter. It was a concept study including a market study, competitor analysis and a preliminary design. We were working on it as a project partner in some work packages. Our main part was to make the preliminary design of an aircraft which could fulfill the defined mission profile which resulted from the market study.

G: Is it some kind of a logistic problem?
SJ: Yes of course, today often big cargo aircraft are used to transport small and light express cargo. Everyone can imagine that it is not efficient and economic when an aircraft with a maximum payload of around 100 tons transports only a few tons of cargo. But the customer pays for it, because it is so urgent and no small freighters are available. So it makes sense to provide an appropriate freighter for this market niche.

G: And what was the result of this project?
SJ: Our part was the technical one, so we got the specification (mission profile) and we did a preliminary design. Preliminary design means the general layout and sizing: is it a high or low wing configuration, the configuration of the tail and fuselage, wing-sizing and wing geometry, the calculation of the required thrust (selection of an appropriate engine) and the design of the high lift devices. Because there is also the requirement to serve small airfields the transporter should be designed for short landing and take-off. So the main purpose was to design an aircraft to make the cargo market more efficient and flexible.

G: How can you see the future of aviation from a technical point of view? What are the main directions of the developments?
SJ: I think the future will lead to the use of alternative fuels (for example biofuel) and alternative propulsion systems. These days there are also some research projects done by the DLR (Deutsches Zentrum für Luft- und Raumfahrt) to use fuel cells for the electrical supply of aircraft and to replace the APU (auxiliary power unit). Also the use of electrical nose wheels was already tested. With such nose wheels aircraft can taxi to the runway without using the engine. This reduces emissions and noise because the engine run-up can be done later.

G: Do you believe, that biofuels will be really used worldwide in the next 30 year?
SJ: Yes, I think that the use of biofuel in aviation will rise in the next years. But to fulfill the demand for biofuel the production has to be increased. Producing biofuels needs agricultural area. I think a lot of studies and research has to be done in the future to ensure that biofuel is produced in a sustainable way and the production never competes with food production.

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