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Hydrogen is widely considered a promising fuel for future transportation applications for both, internal combustion engines and fuel cells. Due to their advanced stage of development and immediate availability hydrogen combustion engines could act as a bridging technology towards a wide-spread hydrogen infrastructure. Although fuel cell vehicles are expected to surpass hydrogen combustion engine vehicles in terms of efficiency, the difference in efficiency might not be as significant as widely anticipated [1]. Hydrogen combustion engines have been shown capable of achieving efficiencies of up to 45 % [2]. One of the remaining challenges is the reduction of nitric oxide emissions while achieving peak engine efficiencies. This paper summarizes research work performed on a single-cylinder hydrogen direct injection engine at Argonne National Laboratory.

The addition of exhaust gas recirculation (EGR) has demonstrated the potential to significantly improve engine efficiency by allowing high CR operation due to a reduction in knock tendency, heat transfer, and pumping losses. In addition, EGR also reduces the engine-out emission of nitrogen oxides, particulates, and carbon monoxide while further improving efficiency at stoichiometric air/fuel ratios. However, improvements in efficiency through enhanced combustion phasing at high compression ratios can result in a significant increase in cylinder pressure. As cylinder pressure and temperature are both important parameters for estimating the durability requirements of the engine - in effect specifying the material and engineering required for the head and block - the impact of EGR on surface temperatures, when combined with the cylinder pressure data, will provide an important understanding of the design requirements for future cylinder heads.

Since transient vehicle HVAC computational fluids (CFD) simulations take too long to solve in a production environment, the goal of this project is to automatically create a lumped-parameter flow network from a steady-state CFD that solves nearly instantaneously. The data mining algorithm k-means is implemented to automatically discover flow features and form the network (a reduced order model). The lumped-parameter network is implemented in the commercial thermal solver MuSES to then run as a fully transient simulation. Using this network a “localized heat transfer coefficient” is shown to be an improvement over existing techniques. Also, it was found that the use of the clustering created a new flow visualization technique. Finally, fixing clusters near equipment newly demonstrates a capability to track localized temperatures near specific objects (such as equipment in vehicles).

Southwest Research Institute (SwRI) converted a 2012 Buick Regal GS to use an engine with Dedicated EGR™ (D-EGR™). D-EGR is an engine concept that uses fuel reforming and high levels of recirculated exhaust gas (EGR) to achieve very high levels of thermal efficiency [1]. To accomplish reformation of the gasoline in a cost-effective, energy efficient manner, a dedicated cylinder is used for both the production of EGR and reformate. By operating the engine in this manner, many of the sources of losses from traditional reforming technology are eliminated and the engine can take full advantage of the benefits of reformate. The engine in the vehicle was modified to add the following components: the dedicated EGR loop, an additional injector for delivering extra fuel for reformation, a modified boost system that included a supercharger, high energy dual coil offset (DCO) ignition and other actuators used to enable the control of D-EGR combustion.

The ongoing pursuit of improved engine efficiency and emissions is driving gasoline low-pressure loop EGR systems into production around the globe. The Dedicated EGR (D-EGR®) engine was developed to minimize some of the challenges of cooled EGR while maintaining its advantages. The D-EGR engine is a high efficiency, low emissions internal combustion engine for automotive and off-highway applications. The core of the engine development focused on a unique concept that combines the efficiency improvements associated with recirculated exhaust gas and the efficiency improvements associated with fuel reformation. To outline the differences of the new engine concept with a conventional LPL EGR setup, a turbocharged 2.0 L PFI engine was modified to operate in both modes. The second part of the cooled EGR engine concept comparison investigates efficiency, knock resistance, combustion stability, and maximum load potential at high load conditions.

In light of the increasingly stringent efficiency and emissions requirements, several new engine technologies are currently under investigation. One of these new concepts is the Dedicated EGR (D-EGR®) engine. The concept utilizes fuel reforming and high levels of recirculated exhaust gas (EGR) to achieve very high levels of thermal efficiency. While the positive impact of reformate, in particular hydrogen, on gasoline engine performance has been widely documented, the on-board reforming process and / or storage of H2 remains challenging. The Water-Gas-Shift (WGS) reaction is well known and has been used successfully for many years in the industry to produce hydrogen from the reactants water vapor and carbon monoxide. For this study, prototype WGS catalysts were installed in the exhaust tract of the dedicated cylinder of a turbocharged 2.0 L in-line four cylinder MPI engine. The potential of increased H2 production in a D-EGR engine was evaluated through the use of these catalysts.

In this work, a dynamically loaded hydrodynamic journal bearing test rig is developed and introduced. The rig is a novel design, using a hydraulic actuator with fast acting spool valves to apply load to a connecting rod. This force is transmitted through the connecting rod to the large end bearing which is mounted on a spinning shaft. The hydraulic actuator allows for fully variable control and can be used to apply either static load in compression or tension, or dynamic loading to simulate engine operation. A variable speed electric motor controls shaft speed and is synchronized to the hydraulic actuator to accurately simulate loading to represent all four engine strokes. A high precision torque meter enables direct measurements of friction torque, while shaft position is measured via a high precision encoder.

The study of spray-wall interaction is of great importance to understand the dynamics that occur during fuel impingement onto the chamber wall or piston surfaces in internal combustion engines. It is found that the maximum spreading length of an impinged droplet can provide a quantitative estimation of heat transfer and energy transformation for spray-wall interaction. Furthermore, it influences the air-fuel mixing and hydrocarbon and particle emissions at combusting conditions. In this paper, an analytical model of a single diesel droplet impinging on the wall with different inclined angles (α) is developed in terms of βm (dimensionless maximum spreading length, the ratio of maximum spreading length to initial droplet diameter) to understand the detailed impinging dynamic process.

The worldwide trend of tightening CO2 emissions standards and desire for near zero emissions is driving development of high efficiency natural gas engines for a low CO2 replacement of traditional diesel engines. A Cummins Westport ISX12 G was previously converted to a Dedicated EGR® (D-EGR®) configuration with two out of the six cylinders acting as the EGR producing cylinders. Using a systems approach, the combustion and turbocharging systems were optimized for improved efficiency while maintaining the potential for achieving 0.02 g/bhp-hr NOX standards. A prototype variable nozzle turbocharger was selected to maintain the stock torque curve. The EGR delivery method enabled a reduction in pre-turbine pressure as the turbine was not required to be undersized to drive EGR. A high energy Dual Coil Offset (DCO®) ignition system was utilized to maintain stable combustion with increased EGR rates.

Improving vehicle response through advanced knowledge of traffic behavior can lead to large improvements in energy consumption for the single isolated vehicle. This energy savings across multiple vehicles can even be larger if they travel together as a cohort in harmonization. Additionally, if the vehicles have enough information about their immediate path of travel, and other vehicles’ in that path (and their respective critical forward-looking information), they can safely drive close enough to each other to share aerodynamic load. These energy savings can be upwards of multiple percentage points, and are dependent on several criteria. This analysis looks at criteria that contributes to energy savings for a cohort of vehicles in synchronous motion, as well as describes a study that allows for better understanding of the potential benefits of different types of cohorted vehicles in different platoon arrangements.

Downsizing is an important concept to reduce fuel consumption as well as emissions of spark ignition engines. Engine displacement is reduced in order to shift operating points from lower part load into regions of the operating map with higher efficiency and thus lower specific fuel consumption [ 1 ]. Since maximum power in full load operation decreases due to the reduction of displacement, engines are boosted (turbocharging or supercharging), which leads to a higher specific loading of the engines. Hence, a new combustion phenomenon has been observed at high loads and low engine speed and is referred to as Low-Speed Pre-Ignition or LSPI. In cycles with LSPI, the air/fuel mixture is ignited prior to the spark which results in the initial flame propagation quickly transforming into heavy engine knock. Very high pressure rise rates and peak cylinder pressures could exceed design pressure limits, which in turn could lead to degradation of the engine.

The general benefits of automation are well documented. Order of magnitude improvements are achievable in processing speeds, production rates, and efficiency. Other benefits include improved process consistency (inversely, reduced process variation), reduced waste and energy consumption, and risk reduction to operators. These benefits are especially true for the automation of the aerospace paint removal (or "depaint") processes. Southwest Research Institute® (SwRI®) developed and implemented two systems in the early 1990s for depainting full-body fighter aircraft at Robins Air Force Base (AFB) at Warner Robins, Georgia, and Hill AFB at Ogden, Utah. These systems have been in production use, almost continuously for approximately 20 years, for the depainting of the F-15 Eagle and the F-16 Falcon fighter aircraft, respectively.

This paper presents an overview of the connected controls and optimization system for vehicle dynamics and powertrain operation on a light-duty plug-in multi-mode hybrid electric vehicle developed as part of the DOE ARPA-E NEXTCAR program by Michigan Technological University in partnership with General Motors Co. The objective is to enable a 20% reduction in overall energy consumption and a 6% increase in electric vehicle range of a plug-in hybrid electric vehicle through the utilization of connected and automated vehicle technologies. Technologies developed to achieve this goal were developed in two categories, the vehicle control level and the powertrain control level. Tools at the vehicle control level include Eco Routing, Speed Harmonization, Eco Approach and Departure and in-situ vehicle parameter characterization.

There is growing interest in additive manufacturing technologies for prototype if not serial production of complex internal combustion engine components such as cylinder heads and pistons. In support of this general interest the authors undertook an experimental bench test to evaluate opportunities for cooling jacket improvement through geometries made achievable with additive manufacturing. A bench test rig was constructed using electrical heating elements and careful measurement to quantify the impact of various designs in terms of heat flux rate and convective heat transfer coefficients. Five designs were compared to a baseline - a castable rectangular passage. With each design the heat transfer coefficients and heat flux rates were measured at varying heat inputs, flow rates and pressure drops. Four of the five alternative geometries outperformed the baseline case by significant margins.

The application of hydrogen (H2) as an internal combustion (IC) engine fuel has been under investigation for several decades. The favorable physical properties of hydrogen make it an excellent alternative fuel for fuel cells as well as IC engines and hence it is widely regarded as the energy carrier of the future. The potential of hydrogen as an IC engine fuel can be optimized by direct injection (DI) as it provides multiple degrees of freedom to influence the in-cylinder combustion processes and consequently the engine efficiency and exhaust emissions. This paper studies a single-hole nozzle and examines the effects of injection strategy on engine efficiency, combustion behavior and NOx emissions. The experiments for this study are done on a 0.5 liter single-cylinder research engine which is specifically designed for combustion studies and equipped with a cylinder head that allows side as well as central injector location.

The performance and efficiency of spark ignited gasoline engines is often limited by end-gas knock. In particular, when operating the engine at high loads, combustion phasing is retarded to prevent knock, resulting in a significant reduction of engine efficiency. Since the invention of the spark ignition (SI) engine, much work has been devoted to improve and regulate fuel characteristics, such as octane number, to suppress engine knock. The auto-ignition tendency of the engine lubricant however, as described by cetane number (CN), has received little attention, as it has been assumed that engine lubricant effects on knock are insignificant, primarily due to low levels of average oil consumption. However, with modern SI engines being developed to operate at higher loads and closer to knock limits, the reactivity of engine lubricants can impact the knock behavior.

Commercial vehicles are moving in the direction of improving brake thermal efficiency while also meeting future diesel emission requirements. This study is focused on improving efficiency by replacing the variable geometry turbine (VGT) turbocharger with a high-efficiency fixed geometry turbocharger. Engine-out (EO) NOX emissions are maintained by providing the required amount of exhaust gas recirculation (EGR) using a 48 V motor driven EGR pump downstream of the EGR cooler. This engine is also equipped with cylinder deactivation (CDA) hardware such that the engine can be optimized at low load operation using the combination of the high-efficiency turbocharger, EGR pump and CDA. The exhaust aftertreatment system has been shown to meet 2027 emissions using the baseline engine hardware as it includes a close coupled light-off SCR followed by a downstream SCR system.

Connected and automated driving technology is known to improve real-world vehicle efficiency by considering information about the vehicle’s environment such as traffic conditions, traffic lights or road grade. This study shows how the powertrain of a hybrid-electric vehicle realizes those efficiency benefits by developing methods to directly measure real-time transient power losses of the vehicle’s powertrain components through chassis-dynamometer testing. This study is a follow-on to SAE Technical Paper 2019-01-0116, Test Methodology to Quantify and Analyze Energy Consumption of Connected and Automated Vehicles [1], to understand the sources of efficiency gains resulting from connected and automated vehicle driving. A 2017 Toyota Prius Prime was instrumented to collect power measurements throughout its powertrain and driven over a specific driving schedule on a chassis dynamometer.

A 2-D CFD model was developed to describe the heat transfer, and reaction kinetics in a honeycomb structured ceramic diesel particulate trap. This model describes the steady state as well as the transient behavior of the flow and heat transfer during the trap regeneration processes. The trap temperature profile was determined by numerically solving the 2-D unsteady energy equation including the convective, heat conduction and viscous dissipation terms. The convective terms were based on a 2-D analytical flow field solution derived from the conservation of mass and momentum equations (Opris, 1997). The reaction kinetics were described using a discretized first order Arrhenius function. The 2-D term describing the reaction kinetics and particulate matter conservation of mass was added to the energy equation as a source term in order to represent the particulate matter oxidation. The filtration model describes the particulate matter accumulation in the trap.

This study focuses on how to predict hot spots of one of the cylinders of a V8 5.4 L FORD engine running at full load. The KIVA code with conjugate heat transfer capability to simulate the fast transient heat transfer process between the gas and the solid phases has been developed at the Michigan Technological University and will be used in this study. Liquid coolant flow was simulated using FLUENT and will be used as a boundary condition to account for the heat loss to the cooling fluid. In the first step of calculation, the coupling between the gas and the solid phases will be solved using the KIVA code. A 3D transient wall heat flux at the gas-solid interface is then compiled and used along with the heat loss information from the FLUENT data to obtain the temperature distribution for the engine metal components, such as cylinder wall, cylinder head, etc.