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Diesel particulate filters (DPFs) are well assessed aftertreatment devices, equipping almost every modern diesel engine on the market to comply with today's stringent emission standards. However, an accurate estimation of soot loading, which is insttumental to ensuring optimal performance of the whole engine-after-treatment assembly, is stilt a major challenge. In fact, several highly coupled physical-chemical phenomena occur at the same time, and a vast number of engine and exhaust dependent parameters make this task even more daunting. This challenge may he solved with models characterized by different degrees of detail (0-D to 3-D} depending on the specific application. However, the use of real-time, but accurate enough models, may be the primat y hurdle that has to be overcome when confronted with advanced exhaust emissions control challenges, such as the integration of the DPF with the engine or other critical aftertreatment components (selective catalytic reduction or other A/O, control components), or to properly develop model-based OBD sensors. This paper aims at addressing real time DPF modeling issues with special regard to key parameter settings, by using the 1-D code called E.xhAUST (exhaust aftertreatment unified simulation tool), which was jointly developed by the University of Rome Tor Vergata and West Virginia University. ExhAUST is characterized by a novel and unique full analytical treatment of the wall that allows a highly detailed representation of the soot loading evolution inside the DPF porous matrix. Numerical results are compared with experimental data gathered at West Virginia University engine laboratory using a MY2004 Mack'MP7-355E, an II liter, 6-cylinder, inline heavy-duty diesel engine coupled to a Johnson Matthey CCRT diesel oxidation catalyst -f CDPF, catalyzed DPF exhau.'it aftertreatment system. To that aim, the engine test bench was equipped with a DPF weighing system to track soot loading over a specifically developed engine operating procedure. Residts indicate that the model is accurate enough to capture .wot loading and back pressure histories with regard to different steady state engine operating points, without a need for any tuning procedure of the key parameters. Thus, the use of ExhAUST for application to advanced after-treatment control appears to be a promising tool at this .stage.

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This paper describes the development of small rotary internal combustion engines developed to operate on the High Efficiency Hybrid Cycle (HEHC). The cycle, which combines high compression ratio (CR), constant-volume (isochoric) combustion, and overexpansion, has a theoretical efficiency of 75% using air-standard assumptions and first-law analysis. This innovative rotary engine architecture shows a potential indicated efficiency of 60% and brake efficiency of >50%. As this engine does not have poppet valves and the gas is fully expanded before the exhaust stroke starts, the engine has potential to be quiet. Similar to the Wankel rotary engine, the 'X' engine has only two primary moving partsa shaft and rotor, resulting in compact size and offering low-vibration operation. Unlike the Wankel, however, the X engine is uniquely configured to adopt the HEHC cycle and its associated efficiency and low-noise benefits. The result is an engine which is compact, lightweight, low-vibration, quiet, and fuel-efficient. Two prototype engines are discussed. The first engine is the larger X1 engine (70hp), which operates on the HEHC with compression-ignition (CI) of diesel fuel. A second engine, the XMv3, is a scaled down X engine (70cc / 3HP) which operates with spark-ignition (SI) of gasoline fuel. Scaling down the engine presented unique challenges, but many of the important features of the X engine and HEHC cycle were captured. Preliminary experimental results including firing analysis are presented for both engines. Further tuning and optimization is currently underway to fully exploit the advantages of HEHC with the X architecture engines.

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Diesel Particulate Filters (DPFs) are well assessed aftertreatment devices, equipping almost every modern diesel engine on the market to comply with today’s stringent emission standards. However, an accurate estimation of soot loading, which is instrumental to ensuring optimal performance of the whole engine-after-treatment assembly is still a major challenge. In fact, several highly coupled physical-chemical phenomena occur at the same time, and a vast number of engine and exhaust dependent parameters make this task even more daunting. This challenge may be solved with models characterized by different degrees of detail (0-D to 3-D) depending on the specific application. However, the use of real-time, but accurate enough models, may be of primary importance to face with advanced control challenges, such as the integration of the DPF with the engine or other critical aftertreatment components (Selective Catalytic Reduction (SCR) or other NOx control components), or to properly develop model-based OBD sensors. This paper aims at addressing real time DPF modeling issues with special regard to key parameter settings, by using the 1D code ExhAUST (Exhaust Aftertreatment Unified Simulation Tool), developed jointly by the University of Rome Tor Vergata and West Virginia University. ExhAUST is characterized by a novel and unique full analytical treatment of the wall that allows faithful representation with high degree of detail the evolution of soot loading inside the porous matrix. Numerical results are compared with experimental data gathered at West Virginia University (WVU) engine laboratory using a Mack heavy-duty diesel engine coupled to a Johnson Matthey CCRT (DOC, Diesel Oxidation Catalyst+CDPF, Catalyzed DPF) aftertreatment system. To that aim, the engine test bench has been equipped with a DPF weighing setup to track soot load over a specifically developed engine operating procedure. Obtained results indicate that the model is accurate enough to capture soot loading and back pressure histories with regard to different steady state engine operating points, without needing any tuning procedure of the key parameters. Thus, the use of ExhAUST for application to advanced after-treatment control appears promising at this stage.