Your Selections

Fragkiadoulakis, Pavlos
Show Only


File Formats

Content Types









SCR System Optimization and Control Supported by Simulation Tools

Aristotle University of Thessaloniki-Grigorios C. Koltsakis, Pavlos Fragkiadoulakis, Zissis Samaras
Exothermia SA-Christos Manetas
Published 2013-04-08 by SAE International in United States
The successful design and especially the control of the SCR system is a challenging process that can be supported by the application of simulation tools. As a first step, we employ physico-chemically informed ‘off-line’ models that are calibrated with the help of targeted small- and full-scale tests. Despite their high level of sophistication, this SCR model is able to be integrated in a control-oriented simulation software platform and connected to other powertrain simulation blocks. The target is to use this simulation platform as a virtual environment for the development and optimization of SCR control strategies. The above process is demonstrated in the case of a passenger car SCR. The model is calibrated at both fresh and aged catalyst condition and validated using experimental data from the engine bench under a wide variety of operating conditions. Next, the calibrated model was coupled with embedded control models, developed for Euro 6 passenger car powertrains. The final simulation platform enabled the precalibration and optimization of dosing control strategies, saving significant experimental effort and costs. Finally, it allowed the…
Annotation icon

Exhaust Particle Sensor for OBD Application

Aristotle Univ. Thessaloniki-Leonidas Ntziachristos, Pavlos Fragkiadoulakis, Zissis Samaras
Pegasor Oy-Kauko Janka, Juha Tikkanen
Published 2011-04-12 by SAE International in United States
Efforts to develop a sensor for on-board diagnostics (OBD) of diesel vehicles are intensive as diesel particulate filters (DPFs) have become widespread around the world. This study presents a novel sensor that has been successfully tested for OBD diagnosis of damaged DPFs. The sensor is based on the "escaping current" technique. Based on this, a sample of exhaust gas is charged by a corona-ionized flow and is pumped by an ejector dilutor built in the sensor's construction. While the majority of ions return to the grounded sensor's body, a small quantity is lost with the charged particles exiting the sensor. This "escaping current" is a measurement of the particle concentration in the exhaust gas. Such a sensor has been developed and tested in real-exhaust of a diesel car and a diesel engine. The sensor provides high resolution (1 Hz, 0.3 s response time) and high sensitivity superseding OBD requirements. The sensor was used on an engine to monitor the efficiency of damaged DPFs. The signal was found to perform similar to the smokemeter, a widespread…
Annotation icon