Documents disponibles écrits par cet auteur

Validation of an infrared extinction method for fuel vapor concentration measurements towards the systematic comparison between alternative and conventional fuels for aviation / Johannes Fritzer in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 1 (Janvier 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 1 (Janvier 2012) . - 08 p. Titre : Validation of an infrared extinction method for fuel vapor concentration measurements towards the systematic comparison between alternative and conventional fuels for aviation Type de document : texte imprimé Auteurs : Johannes Fritzer, Auteur ; Fabrice Giuliani, Auteur ; Strzelecki, Alain, Auteur ; Virginel Bodoc, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Avionics  Chemical  variables  measurement  Climate  mitigation  Combustion  Fossil  fuels  Infrared  detectors  Iterative  methods  Measurement  by  laser  beam  Mie  scattering  Optimisation  Sprays  Transportation Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Due to increasing oil prices and the obvious influence of the combustion of fossil fuel-derivatives on climate change on the one hand and the steady growth of transportation needs on the other, it is necessary to develop alternatives to oil for aviation. For this purpose a specific research program on the investigation of adequate alternative fuels for aviation has been founded by the European Commission's Framework Program. The project Alfa Bird (Alternative Fuels and Bio-fuels in Aircraft Development) focuses on an identification of possible alternative fuels to kerosene, the investigation of the adequacy of the selected ones, an evaluation of the environmental and economic impact of them, and finally the creation of a future perspective for the industrial use of the “best” alternative. The main part of the investigation activities at TU Graz, in cooperation with ONERA Centre de Toulouse and Fauga-Mauzac on these specific topics consists of the analysis of the evaporation of the previously chosen fuel types in comparison to fully synthetic jet fuel. Therefore qualitative measurements to obtain vapor concentration gradients will be done using the infrared extinction (IRE) measurement method. Based on a simplified Beer–Bouguer–Lambert law the integral vapor concentrations can be obtained. The main hypothesis is that if the line-of-sight extinction due to Mie-scattering is similar for both infrared and visible wavelengths because of the presence of the spray, only infrared light will be absorbed by the fuel vapor, being transparent to visible light. This contribution focuses on the validation of the infrared measurement technique on a well characterized spray. The tests are performed under controlled boundary conditions. Therefore an existing IRE test arrangement at ONERA Toulouse using an ultrasonic atomizer injecting n-octane at atmospheric conditions has been analyzed. Error sources related to misalignments in the hardware have been considered and an iterative alignment method of the laser beams followed by a beam diameter and diffraction analysis have been performed. Optimizing the setup to obtain a stable operation point has been successful. Improved experimental results at this operation point were compared with existing simulation results for the evaporation of the ultrasonic atomizer used. The achieved data has shown good accordance to the existing simulation results. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000001 [...] [article] Validation of an infrared extinction method for fuel vapor concentration measurements towards the systematic comparison between alternative and conventional fuels for aviation [texte imprimé] / Johannes Fritzer, Auteur ; Fabrice Giuliani, Auteur ; Strzelecki, Alain, Auteur ; Virginel Bodoc, Auteur . - 2012 . - 08 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 1 (Janvier 2012) . - 08 p. Mots-clés : Avionics  Chemical  variables  measurement  Climate  mitigation  Combustion  Fossil  fuels  Infrared  detectors  Iterative  methods  Measurement  by  laser  beam  Mie  scattering  Optimisation  Sprays  Transportation Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Due to increasing oil prices and the obvious influence of the combustion of fossil fuel-derivatives on climate change on the one hand and the steady growth of transportation needs on the other, it is necessary to develop alternatives to oil for aviation. For this purpose a specific research program on the investigation of adequate alternative fuels for aviation has been founded by the European Commission's Framework Program. The project Alfa Bird (Alternative Fuels and Bio-fuels in Aircraft Development) focuses on an identification of possible alternative fuels to kerosene, the investigation of the adequacy of the selected ones, an evaluation of the environmental and economic impact of them, and finally the creation of a future perspective for the industrial use of the “best” alternative. The main part of the investigation activities at TU Graz, in cooperation with ONERA Centre de Toulouse and Fauga-Mauzac on these specific topics consists of the analysis of the evaporation of the previously chosen fuel types in comparison to fully synthetic jet fuel. Therefore qualitative measurements to obtain vapor concentration gradients will be done using the infrared extinction (IRE) measurement method. Based on a simplified Beer–Bouguer–Lambert law the integral vapor concentrations can be obtained. The main hypothesis is that if the line-of-sight extinction due to Mie-scattering is similar for both infrared and visible wavelengths because of the presence of the spray, only infrared light will be absorbed by the fuel vapor, being transparent to visible light. This contribution focuses on the validation of the infrared measurement technique on a well characterized spray. The tests are performed under controlled boundary conditions. Therefore an existing IRE test arrangement at ONERA Toulouse using an ultrasonic atomizer injecting n-octane at atmospheric conditions has been analyzed. Error sources related to misalignments in the hardware have been considered and an iterative alignment method of the laser beams followed by a beam diameter and diffraction analysis have been performed. Optimizing the setup to obtain a stable operation point has been successful. Improved experimental results at this operation point were compared with existing simulation results for the evaporation of the ultrasonic atomizer used. The achieved data has shown good accordance to the existing simulation results. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000001 [...]