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Vehicle-to-everything (V2X) communication, primarily designed for communication between vehicles and other entities for safety applications, is now being studied for its potential to improve vehicle energy efficiency. In previous work, a 20% reduction in energy consumption was demonstrated on a 2017 Prius Prime using V2X-enabled algorithms. A subsequent phase of the work is targeting an ambitious 30% reduction in energy consumption compared to a baseline. In this paper, we present the Eco-routing algorithm, which is key to achieving these savings. The algorithm identifies the most energy-efficient route between an Origin-Destination (O-D) pair by leveraging information accessible through commercially available Application Programming Interfaces (APIs). This algorithm is evaluated both virtually and experimentally through simulations and dynamometer tests, respectively, and is shown to reduce vehicle energy consumption by 10-15% compared to the baseline over real-world routes.

Engine knock is one of the limiting factors in determining the compression ratio and engine efficiency for spark ignited engines. Using the Southwest Research Institute Knock-CoV test method, it was previously shown that the knock limited load versus combustion phasing (CA50) has a constant slope. All of the knock mitigation strategies tested provided a shift to these knock limited loads but also increased the slope. That is, for the same CA50 retard the knock limited load could be increased more. Our hypothesis was that due to fuel sensitivity, or the difference between the RON and MON, the reactions that lead to knock will behave differently as the pressure-temperature history changes with engine speeds and loads. The fuel affects on the knock and CoV limits were studied by testing fuels with various sensitivities including methanol, E85 (85% ethanol) and Iso-octane.

1Increasing adoption of downsized, boosted, spark-ignition engines has improved vehicle fuel economy, and continued improvement is desirable to reduce carbon emissions in the near-term. However, this strategy is limited by damaging preignition events which can cause hardware failure. Research to date has shed light on various contributing factors related to fuel and lubricant properties as well as calibration strategies, but the causal factors behind an individual preignition cycle remain elusive. If actionable precursors could be identified, mitigation through active control strategies would be possible. This paper uses artificial neural networks to search for identifiable precursors in the cylinder pressure data from a large real-world data set containing many preignition cycles. It is found that while follow-up preignition cycles in clusters can be readily predicted, the initial preignition cycle is not predictable based on features of the cylinder pressure.

Conventional diesel combustion (CDC) is known to provide high efficiency and reliable engine performance, but often associated with high particulate matter (PM) and nitrogen oxides (NOX) emissions. Combustion of fossil diesel fuel also produces carbon dioxide (CO2), which acts as a harmful greenhouse gas (GHG). Renewable and low-carbon fuels such as renewable diesel (RD) and methanol can play an important role in reducing harmful criteria and CO2 emissions into the atmosphere. This paper details an experimental study using a single-cylinder research engine operated under dual-fuel combustion using methanol and RD. Various engine operating strategies were used to achieve diesel-like fuel efficiency. Measurements of engine-out emissions and in-cylinder pressure were taken at test conditions including low-load and high-load operating points.

Dedicated-EGR™ (D-EGR™) is a concept where the exhaust of one dedicated cylinder (D-Cyl) is routed into the intake thus producing EGR to be used by the whole engine. The D-Cyl operates rich of stochiometric which produces syngas that enhances the EGR stream permitting faster combustion and greater knock mitigation. Operating an engine using D-EGR improves the knock resistance which can permit a higher compression ratio (CR) thereby increasing efficiency. One challenge of traditional D-EGR is that the D-Cyl combustion becomes unstable operating with both rich and EGR dilute conditions. Therefore, the ‘Split Intake D-EGR’ concept seeks to resolve this problem by feeding fresh air to the D-Cyl, thus allowing even richer operation in the D-Cyl which further increases the H2 and CO yield thereby enhancing the efficiency benefits.

This program involved the detailed evaluation of a novel laser-based in-exhaust ammonia sensor using a diesel fuel-based burner platform integrated with an ammonia injection system. Test matrix included both steady-state modes and transient operation of the burner platform. Steady-state performance evaluation included tests that examined impact of exhaust gas temperature, gas velocity and ammonia levels on sensor response. Furthermore, cross sensitivity of the sensor was examined at different levels of NOX and water vapor. Transient tests included simulation of the FTP test cycles at different ammonia and NOX levels. A Fourier transform infrared (FTIR) spectrometer as well as NIST traceable ammonia gas bottles (introduced into the exhaust stream via a calibrated flow controller) served as references for ammonia measurement.

The automotive sector is rapidly transitioning to decarbonized, electric vehicles solutions. However, due to challenges with such rapid adoption, Internal combustion engines (ICE) are expected to be used for decades to come. In this transition period it is important to continue to improve ICE efficiency. A key design parameter to increase ICE efficiency is the compression ratio. For gasoline engines, the compression ratio is limited so as to avoid knock. Engine designers can employ several strategies to mitigate knock and enable higher compression ratios. In this study, a new methodology has been developed to compare various knock mitigation strategies. By comparing the knock limited load at a given combustion phasing the expected compression ratio increase can be inferred.

Aftertreatment durability demonstration is a required validation exercise for on-road medium and heavy-duty diesel engine certification. The demonstration is meant to validate emissions compliance for the engine and aftertreatment system at full useful life or FUL. Current certification practices allow engine manufacturers to complete partial aging and then extrapolate emissions performance results to FUL. While this process reduces the amount of service accumulation time, it does not consider changes in the aftertreatment deterioration rate. Rather, deterioration is assumed to occur at a linear rate, which may lead to false conclusions relating to emissions compliance. With CARB and EPA’s commitment to the reduction of criteria emissions, emphasis has also been placed on revising the existing certification practices. The updated practices would require engine manufacturers to certify with an aftertreatment system aged to FUL.

Internal combustion engines (ICE) will be a part of personal transportation for the foreseeable future. One recent trend for engines has been downsizing which enables the engine to be run more efficiently over regulatory drive cycles. Due to downsizing, engine power density has increased which leads to problems with engine knock. Therefore, there is an increasing need to find a means to reduce the knock propensity of downsized engines. One of the ways of reducing knock propensity is by introducing Exhaust Gas Recirculation (EGR) into the combustion chamber, however, volumetric efficiency also reduces with EGR which places challenges on the boosting system. The individual benefits of high-pressure (HP-EGR) and low-pressure (LP-EGR) loop EGR system to assist the boosting system of a 2.0 L Gasoline Direct Injection (GDI) production engine are explored in this paper.

This paper describes a new method for measuring oil consumption using laser induced breakdown spectroscopy (LIBS). LIBS focuses a high energy laser pulse on a sample to form a transient plasma. As the plasma cools, each element produces atomic emission lines which can be used to identify and quantify the elements present in the original sample. In this work, a LIBS system was used on simulated engine exhaust with a focus on quantifying the inorganic components (termed ash) of the particulate emissions. Because some of the metallic elements in the ash almost exclusively result from lube oil consumption, their concentrations can also be correlated to an oil consumption rate. Initial testing was performed using SwRI’s Exhaust Composition Transient Operation Laboratory®(ECTO-Lab®) burner system so that oil consumption and ash mass could be precisely controlled.

Southwest Research Institute (SwRI) utilizes the burner-based Exhaust Composition Transient Operation LaboratoryTM (ECTO-Lab) to accurately simulate transient engines and replicate real exhaust that is produced by light and heavy-duty engines for aftertreatment aging and evaluations. This system can generate and dose NOX over transient cycles from a range of 20 ppm to 1200 ppm where the NOX is generated by the in-situ decomposition and combustion of a fuel-bound, nitrogen containing compound. During the combustion and decomposition of the nitrogen containing compound over 95 % of the NOX generated is in the form of NO. To authentically simulate exhaust gases, it is necessary to account for the distribution of the NO to the NO2. Since previous work has established that the decomposition of nitric acid can be utilized as a method to generate NO2, the objective of this project was to develop control of NO and NO2 within SwRI’s ECTO-Lab through the decomposition of nitric acid.

Internal short-circuit in cells/batteries is a phenomenon where there is direct electrical contact between the positive and negative electrodes leading to thermal runaway. The nail penetration tests were used to simulate an internal short circuit within the battery, where a conductive nail was used to pierce the battery cell separator membrane which provided direct electrical contact between the positive and negative electrodes. The batteries tested during this work were common batteries used in existing automotive applications, and they included a nickel manganese cobalt (NMC) battery from a Chevrolet Bolt, a lithium manganese oxide (LMO) battery from a Chevrolet Volt, and a lithium iron phosphate (LFP) battery in a hybrid transit bus. The battery abuse and emissions tests were designed to intentionally drive the three different battery chemistries into thermal runaway while measuring battery temperatures, battery voltages and gaseous emissions.

Internal short-circuit in cells/batteries is a phenomenon where there is direct electrical contact between the positive and negative electrodes leading to thermal runaway. The nail penetration tests were used to simulate an internal short circuit within the battery, where a conductive nail was used to pierce the battery cell separator membrane which provided direct electrical contact between the positive and negative electrodes. The batteries tested during this work were common batteries used in existing automotive applications, and they included a nickel manganese cobalt (NMC) battery from a Chevrolet Bolt, a lithium manganese oxide (LMO) battery from a Chevrolet Volt, and a lithium iron phosphate (LFP) battery in a hybrid transit bus. The battery abuse and emissions tests were designed to intentionally drive the three different battery chemistries into thermal runaway while measuring battery temperatures, battery voltages and gaseous emissions.

A push for more stringent emissions regulations has resulted in larger, increasingly complex aftertreatment solutions. In particular, oxides of nitrogen (NOX) and particulate matter (PM) have been controlled using two separate systems, selective catalytic reduction (SCR) and the catalyze diesel particulate filter (CDPF), or the functionality has been combined into a single device producing the SCR on filter (SCRoF). The SCRoF forgoes beneficial NO2 production present in the CDPF to avoid NH3 oxidation which occurs when using platinum group metals (PGM) for oxidation. In this study, mixed-metal oxides are shown to oxidize NO to NO2 without appreciable NH3 oxidation. This selectivity leads to enhanced performance when combined with a typical Cu-zeolite catalyst.

Increased electrification of future heavy-duty engines and vehicles can enable many new technologies to improve efficiency. Electrified oil pumps are one such technology that provides the ability to reduce or turn off the piston oil cooling jets and simultaneously reduce the oil pump flow to account for the reduced flow rate required. This can reduce parasitic losses and improve overall engine efficiency. In order to study the potential impact of reduced oil cooling, a GT-Power engine model prediction of piston temperature was calibrated based on measured piston temperatures from a wireless telemetry system. A simulation was run in which the piston oil cooling was controlled to target a safe piston surface temperature and the resulting reduction in oil cooling was determined. With reduced oil cooling, engine BSFC improved by 0.2-0.8% compared to the baseline with full oil cooling, due to reduced heat transfer from the elevated piston temperatures.

Water injection is an effective method for knock control in spark-ignition engines. However, the requirement of a separate water source and the cost and complexity associated with a fully integrated system creates a limitation of this method to be used in volume production engines. The engine exhaust typically contains 10-15% water vapor by volume which could be condensed and potentially stored for future use. In this study, the exhaust condensate composition was assessed for its use as an effective replacement for distilled water. Specifically, condensate samples were collected pre and post-three-way catalyst (TWC) and analyzed for acidity and composition. The composition of the pre and post-TWC condensates was found to be similar however, the pre-TWC condensate was mildly acidic. The mild acidity has the potential to corrode certain components in the intake air circuit.

The objective of this research was to mitigate urea-derived deposit formation within selective catalytic reduction (SCR) aftertreatment systems by application of specific superhydrophobic coatings to exhaust pipe surfaces. Coatings were applied using a plasma immersion ion processing (PIIP)-like process denoted LotusFlo™. This process utilizes high DC-impulse power waveforms in conjunction with appropriate chemical precursors to generate coatings suited to a specific application. For the present research, organosiloxane (Lotus-130) and fluorinated organosiloxane (Lotus-131) coated surfaces were evaluated. Deposit accumulation studies were executed using the Exhaust Composition Transient Operation LaboratoryTM (ECTO-LabTM) burner system. An in-situ imaging system was installed in the ECTO-Lab to observe differences in the deposit formation process between coated and uncoated exhaust pipes.

SCR-on-filter, or SCRoF, is an emerging technology for different market segments and vehicle applications. The technology enables simultaneous particulate matter trapping and NOX reduction, and provides thermal management and aftertreatment packaging benefits. However, there is little information detailing the lubricant derived exposure effects on functional SCR performance. A study was conducted to evaluate the impact of various oil consumption pathways on a light duty DOC and SCRoF aftertreatment system. This aftertreatment system was aged utilizing an engine test bench modified to enable increased oil consumption rates via three unique oil consumption pathways. The components were characterized for functional SCR performance, ash morphology, and ash deposition characteristics. This included utilizing techniques, such as SEM / EDS, to evaluate the ash structures and quantify the ash elemental composition.

Lithium plating refers to the phenomenon where lithium metal is deposited onto the surface of the anode instead of being intercalated into the carbon sites of the graphite. The lithium metal will cover a portion of the surface area of the anode, which blocks intercalation sites and increases charge gradients. Lithium plating most often occurs when charging the battery at low ambient temperatures or at a high current rate, but lithium plating formation has also been linked to solid electrolyte interface (SEI) growth towards the later stages of life. Lithium plating may significantly reduce a battery cell’s performance in terms of charge capacity, and if severe enough, the lithium metal may form a bridge across the separator of the cell, leading to short circuits and potential safety concerns. The internal research performed by Southwest Research Institute explored how to create a battery model to detect the formation of lithium plating in real time.

The confluence of increasing fuel economy requirements and increased use of ethanol as a gasoline blend component has led to various studies into the efficiency and performance benefits of higher octane numbers and high ethanol content fuels in modern engines. As part of a comprehensive study of the autoignition of different fuels in both the CFR octane rating engine and a modern, direct injection, turbocharged spark-ignited engine, a series of fuel blends were prepared with varying composition, octane numbers and ethanol blend levels. The paper reports on the third part of this study where cylinder pressures were recorded for fuels under knocking conditions in both a single-cylinder research engine (SCE), utilizing a GM LHU head and piston, as well as the CFR engines used for octane ratings.