News Releases
October 2006
Thin film sensors and thermal barriers:
beginning of the European HEATTOP program
The European Heattop program began on August the 1st for three years. It involves 17 partners: turbine manufacturers like Volvo Aero, Siemens and Rolls Royce, small companies that market sensors like Auxitrol Kema and Vibro-meter, and laboratories and research institutes like VKI, the universities of Lund, Cambridge and Oxford, but also Onera, which is developing technological solutions.
Heattop aims to study and validate, in real and severe environments (up to 1200°C ) some ten thermal and mechanical measurement techniques for applications in the gas turbines used in aeronautics, but also in other industrial sectors. The "Thin Film Sensors" team, directed by Patrick Kayser, will be developing temperature measurements techniques based on thin-film thermocouples on turbine blades. "While our work on this subject previously resulted in certain developments," he said, "it has never been validated on an engine, under real operating conditions at the engine manufacturers, which should be possible by 2009 in the framework of Heattop ."
The innovative aspect of this program is that is associates these thin-film sensors with thermal barriers. This is because engine manufacturers want to be able to measure the temperatures at the interface of the thermal barriers and the turbine blades. "We will also be trying to associate our thermocouples in thin films with these thermal barriers, either by inserting them inside, or by getting closer to the barrier-metal interface," said the research engineer. In this field where there is competition, between Europe and the United States and at the level of turbine manufacturers, the Heattop results could, in the end, lead to industrialization of the most promising technologies. "Participating in this type of program is also an opportunity for our team to open up to other sectors than aeronautics – sectors that could then support our developments." The first laboratory tests should begin in the course of 2007.
Nicolas Carrère rewarded for his work on composites
AMAC (the "association for composite materials"), which includes most researchers working on composites in France, awards the Daniel Valentin prize each year to a researcher less than 35 years old, for work on this type of material. This year, the association chose to reward Nicolas Carrère. For him, composites are no longer news, because starting with his university studies and then his masters at the University of Bordeaux, he dealt with them on placement. After his doctorate, still centered on composites, he wrote his thesis on the theme. "The field is in full expansion," he explained, "and the rate of progress is enormous."
At Onera since 2001, he is working on the multi-scale mechanics of composite materials and the calculation of composite structures, essentially in the framework of Americo, a major research program financed by the DGA (armaments procurement agency), 
whose objective is to develop methods to dimension composite structures better and reduce their certification costs. "Currently, we are in the fourth and last phase of this program, which will be completed in June 2007. This is the validation and demonstration phase that should make it possible for us to show that the original methods we developed during the previous phases can bring a significant gain," summarized Nicolas Carrère, who will receive his prize in June 2007 in the framework of the "National composite days" that will be held in Marseilles.
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Onera involved in Nanores, an ANR project
Used to developing vibrating structures like accelerometers and rate gyros in the Physical Measurements department (DMPH), Olivier Le Traon’s team was entrusted with the design of a vibration sensor based on nano-resonators as part of the ANR’s (national research agency) Nanores project, for which the CEA/Leti is prime contractor. This project, in which the Fundamental Electronics Institute (IEF) at Orsay and manufacturers in various sectors, including PSA, Philips and MBDA, will also be participating, will last for 36 months. The aim is to develop a network of nano-resonators for spectral analysis of broadband vibrations. "In this project, which should lead to the manufacture of a demonstrator, Onera is charged with the design and sensor definition aspects," said Olivier Le Traon, who coordinates the project in his department.
Two of his colleagues are deeply involved in the Nanores project. Steve Masson is working on simulation and mechanical design and Jean Guérard is evaluating the possibilities of processing the signal that can be associated with the sensor. As soon as the project was launched, the Châtillon team faced a challenge: "There is an incompatibility between the low frequency analysis band and the idea of a nano-resonator. The smaller the object, the higher its vibrations," they recalled. These engineers managed to find an original way to get around this apparent contradiction in order to get on with the next phase of execution in the white rooms of the Leti.
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A group of Polytechnique students discovers form memory alloys
For Anne Denquin, who agreed to supervise seven Ecole Polytechnique students in their scientific project, it was a first. Interested by form memory alloys, this group’s objective was to design a hanger with form memory to avoid ironing tee-shirts. As she had been working for nearly two years on form memory alloys at high temperature (900° to 1000° C), the research engineer at Onera’s Metallic Materials and Processes department (DMMP) was thus a well-suited tutor for these students, who did not want to just do a bibliographical study, but wanted to get into research and come out with a product. "They were especially interested in nickel-titanium alloy and its phase transitions. They took part in various experiments with Karine Chastaing, a doctoral student, and also with the team of her thesis director, profession Richard Portier of the Structural Metallurgy Laboratory of the Ecole Nationale Supérieure of chemistry in Paris ," summarized Anne Denquin. This project began in October 2005 and was completed last June by the presentation of a demonstrator when this original work was classified second out of some 70 projects. "That was an enriching experience. Above all, these students discovered what research is really like. In my opinion, that is what’s most important."
