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For the EcoCAR 2 collegiate engineering competition, The University of Tennessee is modifying a 2013 Chevrolet Malibu Eco from a mild hybrid into a series-parallel plug-in hybrid electric vehicle. For this design, the team is exchanging the engine for one that is E85 compatible, slightly separating the engine and transmission, and coupling an electric generator to the engine. In the rear of the vehicle, a modified all-wheel drive subframe will be implemented. This subframe will house a traction motor and a single gear electric drive transmission. A custom fuel tank and fuel system will be constructed for the vehicle, in order to use E85 fuel. Furthermore, an energy storage system will be placed in the rear of the vehicle, in the trunk and spare tire space. Modifications for the packaging must be made and analysis must be performed to validate the structural integrity of all modifications.

The University of Tennessee, Knoxville's (UTK) EcoCAR 2 team developed a Series-Parallel Plug-In Hybrid Electric Vehicle (PHEV) that utilizes E85 fuel. The vehicle was developed and modeled in Year One of the EcoCAR 2 competition. The team has spent Year Two refining the theoretical design from Year One and implementing the design into a working mule vehicle. The developed architecture has been integrated into a 2013 Chevrolet Malibu, which was donated by General Motors. The team focused on strengthening the replacement and modified components, integrating the new vehicle components, bench testing the vehicle controller and implementing the entire design into a working vehicle.

Plug-in hybrid electric vehicles (PHEV) operate predominantly as electric vehicles (EV) with intermittent assist from the engine. As a consequence, the engine can be subjected to multiple cold start events. These cold start events have a significant impact on tailpipe emissions due to degraded catalyst performance and starting the engine under less than ideal conditions. On current conventional vehicles, the first cold start of the engine dictates whether or not the vehicle will pass federal emissions tests. PHEV operation compounds this problem due to infrequent, multiple engine cold starts. ORNL, in collaboration with the University of Tennessee, developed an Engine-In-the-Loop (EIL) test platform to investigate cold start emissions on a 2.0l Gasoline Turbocharged Direct Injection (GTDI) Ecotec engine coupled to a virtual series hybrid electric vehicle.

The University of Tennessee, Knoxville's (UTK) EcoCAR 2 team chose to develop a Plug-In Series-Parallel Hybrid Electric Vehicle that will utilize E-85 fuel. The architecture will be integrated into a 2013 Chevrolet Malibu, donated by General Motors. Throughout the first year of the competition, Tennessee implemented the EcoCAR 2 Vehicle Development Process. The team focused on the development of the supervisory controller through software simulations and Hardware-in-the-Loop (HIL) simulations. Simultaneously, packaging studies were performed via Computer Aided Design (CAD) for powertrain components, as well as the development of the energy storage system, and finite-element analysis (FEA) of modified vehicle components.

Plug-in hybrid electric vehicle (PHEV) technologies have the potential for considerable petroleum consumption reductions, possibly at the expense of increased tailpipe emissions due to multiple “cold” start events and improper use of the engine for PHEV specific operation. PHEVs operate predominantly as electric vehicles (EVs) with intermittent assist from the engine during high power demands. As a consequence, the engine can be subjected to multiple cold start events. These cold start events may have a significant impact on the tailpipe emissions due to degraded catalyst performance and starting the engine under less than ideal conditions. On current hybrid electric vehicles (HEVs), the first cold start of the engine dictates whether or not the vehicle will pass federal emissions tests. PHEV operation compounds this problem due to infrequent, multiple engine cold starts.

This paper describes the on-road evaluation of emissions from student-produced biodiesel. The study compared the emissions of B100, B50 and B20 with commercial ULSD. A modern diesel vehicle powered by a 1.9L turbocharged direct injected compression ignition (DIG) engine was used along with the Original Equipment Manufacturer (OEM) oxidation catalyst and diesel particulate filter. A portable emissions measurement system (PEMS) was used to measure tailpipe NOx, CO and HC. The on-road drive cycle was conducted in a mixture of city and interstate driving. Repeatability and accuracy of the drive-cycle was evaluated. The study found that NOx increased with the amount of biodiesel in the fuel. The study also found that tailpipe CO was insignificant with all blends tested. The HC data using the PEMS were not useful.

Recent investigations of advanced combustion have demonstrated that simultaneous low engine-out nitrogen oxides and particular matter emissions are possible, without a decrease in efficiency. So-named High Efficiency Clean Combustion (HECC) or Modulated Kinetics (MK) modes reduce NOx and PM due to low temperature combustion, including premixed combustion along with prolongation of the ignition delay. Theoretical research using powerful computational tools looks very promising because of the possibility of performing parametric analyses, incorporating simultaneous variation of an unlimited number of engine parameters. Relatively low temperatures in some zones of the diesel engine cylinder corresponding to the HECC regimes require application of chemical kinetics to the numerical simulation of this advanced mode of combustion because of low rates of the chemical reactions compared to the small residence time of the combustion products in the cylinder.

As interest has grown in diesel emissions and diesel engine aftertreatment, so has the importance of analyzing all components of the exhaust. One of the more costly and difficult measurements to make is the collection and analysis of semivolatile organic compounds (SOCs) in the exhaust. These compounds include alkane and alkenes from C12-C24, and the 2-5 ring polycyclic aromatic hydrocarbons (PAH). These compounds can be present in both the particulate (i.e. on the filter) and gaseous phase, and cannot be collected with bag samples. Typically, a sorbent is used downstream of the particulate collection filters to collect these compounds. Sorbent phases include polyurethane foam (PUF), Tenax™, XAD-type resins, and activated carbon. The SOCs are removed from the sorbent either by solvent extraction (PUF and XAD) or thermal desorption (Tenax™ and activated carbon). Each of these methods have advantages and disadvantages.