The Aerosol and Particle Technology Laboratory (APTL) of CERTH/CPERI was established in 1996, with the objective to conduct basic and applied research as well as to develop new technological products relying on the understanding of the science of fine particles and their suspensions in various media. The Laboratory’s growth and development strategy has been based on well acknowledged market needs, offering solutions in many Environmental/Health, Energy and Materials/Process Industries related issues. The exploitation of computational technology has had a central role in the R&D work at APTL since its establishment, both in the design/analysis of experimental work as well as in the transfer of scientific results to the industry.
The Fluent code came into use at APTL in 1998 and the SimTec team has supported us throughout our evolution as users of this CFD platform, from early exploratory steps up to advanced use of User Defined Functions for the coupling of our in-house aerosol dynamics and filtration media models. It has been a great benefit to have this enduring support available in our home city of Thessaloniki and a pleasure to have collaborated with SimTec Ltd. in the hosting of the Southeastern Europe Fluent UGM 2002. In spite of accumulated experience, for the future APTL continues to look forward to support from SimTec Ltd for maintaining a state-of-the-art and cost-effective tool set within the very dynamic CFD landscape.
Project 1. Coated Sintered Metal Trap (COMET)
European Commission GROWTH Programme project contract G3RD-CT-2002-00811 (2002-2005).
The COMET project was part of a proactive response to the strict reductions in heavy duty Diesel engines emissions, at the time planned to become effective in 2005 (Euro IV limits) and in 2008 (Euro V limits). The focus of the COMET project was to investigate emission control systems for heavy duty engines based on the use of sintered metal filter media for the Diesel soot particulate trap. The investigation covered all aspects of the soot filter system, from the material microstructure level, where catalytic coating technologies were considered, all the way up to the application scale where the aerodynamic behaviour was critical to both system performance as well as robustness. The central element of the sintered metal soot traps is a block of pleated sheet material, with sintered metal filter media being stacked and edge-to-edge welded in such a way so as to provide a large filtration surface area within a relatively compact volume. This stacked/pleated geometry posed a major challenge for the CFD simulation effort needed to understand the system aerodynamic behaviour – it was neither possible to represent the flow between the pleats directly (computationally intractable) nor was the filter medium block amenable to effective porous medium representation due to the presence of distinct in-flow (with soot) and out-flow (cleaned exhaust) spaces, coupled to each other by the pressure and by the continuity condition. APTL developed a suite of UDFs in Fluent such that the pleated filter medium block could be fully represented at the same mesh resolution as the surrounding exhaust system geometry, thereby meeting project needs.
Project 2. Integrated Material and Information Technologies for Novel Emission Control Systems (IMITEC)
European Commission IST Programme project contract IST-2001-34874 (2001-2004).
The scope of the IMITEC project was to develop an integrated sensor platform for next-generation automotive emission control systems such as Diesel particulate (soot) filters and nitrogen oxide converters, through systems integration of micro/nano materials technologies, virtual sensor simulation algorithms and instrumentation of emission control devices. This research effort was in direct response not only to the market potential of these technologies but also to explicit statements of the European Commission to push emissions sensor development for automotive applications by 2008. The use of Fluent was of fundamental importance to the research effort in relating exhaust flow conditions to mass transfer rate of the measured substances (soot nanoparticles or gaseous pollutants) towards the sensor elements inside protective caps. Different cap designs evaluated with respect to their effect of sensor performance while correlations of exhaust flow conditions and measurant concentration at the sensor surfaces were derived. The use of CFD for the above tasks permitted most experimental resources to then be allocated to the development of the experimental sensor technologies themselves.