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Advanced Cu-zeolite based SCR (selective catalytic reduction) catalyst technologies were evaluated in a laboratory reactor as a component of a diesel LNT (lean NOx trap) plus in-situ SCR system (i.e., NH3 generation over the LNT vs injection via urea). New-generation LNT formulations, with lower desulfation temperatures and improved durability characteristics relative to previous LNTs, were also evaluated. The combined new-generation LNT+Cu-zeolite SCR systems showed a much wider temperature window of high NOx conversion compared to either LNT catalysts alone or LNT+SCR systems utilizing Fe-zeolite SCR catalysts. The new-generation Cu-zeolite SCR catalysts retained high activity even after repeated exposure to high-temperature rich DeSOx conditions in a laboratory 3-mode aging cycle simulating 120,000 mile vehicle driving.

For diesel applications, cold start accounts for a large amount of the total NOx emissions during a typical Federal Test Procedure (FTP) for light-duty vehicles and is a key focus for reducing NOx emissions. A common form of diesel NOx aftertreatment is selective catalytic reduction (SCR) technology. For cold start NOx improvement, the SCR catalyst would be best located as the first catalyst in the aftertreatment system; however, engine-out hydrocarbons and no diesel oxidation catalyst (DOC) upstream to generate an exotherm for desulfation can result in degraded SCR catalyst performance. Recent advances in vanadia-based SCR (V-SCR) catalyst technology have shown better low temperature NOx performance and improved thermal durability. Three V-SCR technologies were tested for their thermal durability and low-temperature NOx performance, and after 600°C aging, one technology showed low-temperature performance on par with state-of-the-art copper-zeolite SCR (Cu-SCR) technology.

This paper presents a comprehensive overview of Brazilian On-Board Diagnostic (OBD) regulations, Inspection and Maintenance (I/M) Programs and Aftermarket Catalyst regulations as well as an overview of similar regulations in the United States and Europe. Opportunities and technical risks are described in this context. Regulatory information contained in this Paper is intended to serve as reference only. Updated and complete rules and regulations must be used for official purposes. The implementation of the second stage of Brazilian OBD (OBDBr-2), starting in 2010, represents a significant improvement towards exhaust emission control and on-board diagnostic monitoring. Its effectiveness and credibility will be heavily influenced by how this new technology is integrated into I/M programs and how well it meshes with aftermarket catalyst regulations. Currently, Brazilian I/M regulations do not incorporate any OBD requirements and only Rio de Janeiro State has implemented an I/M Program.

A laboratory flow reactor study was utilized to determine the durability impact of alkali metal (Na and K) exposure on three Pt/Pd-based diesel oxidation catalysts (DOC), two vanadium-based selective catalytic reduction (SCR) catalysts, and two Cu/zeolite-based SCR catalysts. All catalyst samples were contaminated by direct deposition of Na or K by an incipient wetness technique. The activity impact on the contaminated DOCs was accomplished by evaluating for changes in CO and HC light-off. The activity impact on the contaminated SCR catalysts was accomplished by evaluating for changes in the Standard SCR Reaction, the Fast SCR Reaction, the Ammonia Oxidation Reaction, and the Ammonia Storage Capacity. Contamination levels of 3.0 wt% Na was found to have a higher negative impact on Pt-based and zeolite containing DOCs for T-50 CO and HC light-off.

Phosphorous poisoning on customer-aged catalysts was investigated by material analysis and performance testing. Most of the phosphorus was associated with the oxide components in the washcoat. These contaminants were roughly classified as aluminum phosphate, cerium phosphate, zinc-calcium phosphate. Deactivation of the catalyst with aluminum phosphate was strong and followed a linear correlation from oxalic acid testing. Phosphorus scavenging additives were researched to inhibit increase of aluminum phosphate. According to thermodynamic calculations, lower free energy of compounds of additive and phosphate is expected to prevent formation of aluminum phosphate.

This paper describes a transient, thermodynamic, crank angle-based engine model in Modelica that can be used to simulate a range of advanced engine technologies. A single cylinder model is initially presented and described, along with its validation against steady-state dynamometer test data. Issues related to this single cylinder validation are discussed, including the appropriate conservation of hot residual gases under very early intake valve opening (IVO) conditions. From there, the extension from a single cylinder to a multi-cylinder V8 engine model is explained and simulation results are presented for a transient cylinder-deactivation scenario on a V8 engine.

Emission studies were carried out on clear-fueled and MMT®-fueled 100,000-mile Escort vehicles from the Alliance study [SAE 2002-01-2894]. Alliance testing had revealed substantially higher emissions from the MMT-fueled vehicle, and the present study involved swapping the engine cylinder heads, spark plugs, oxygen sensors, and catalysts between the two vehicles to identify the specific components responsible for the emissions increase. Within 90% confidence limits, all of the emissions differences between the MMT- and Clear-vehicles could be accounted for by the selected components. NMHC emission increases were primarily attributed to the effects of the MMT cylinder head and spark plugs on both engine-out and tailpipe emissions. CO emission increases were largely traced to the MMT cylinder head and its effect on tailpipe emissions. NOx emission increases were linked to the MMT catalyst.

An electromechanically driven valve train offers unprecedented flexibility to optimize engine operation for each speed load point individually. One of the main benefits is the increased fuel economy resulting from unthrottled operation. The absence of a restriction at the entrance of the intake manifold leads to wave propagation in the intake system and makes a direct measurement of air flow with a hot wire air meter unreliable. To deliver the right amount of fuel for a desired air-fuel ratio, we therefore need an open loop estimate of the air flow based on measureable or commanded signals or quantities. This paper investigates various expressions for air charge in camless engines based on quasi-static assumptions for heat transfer and pressure.

This paper describes an investigation into the fluid flow and heat transfer on the windshield as well the effect of the air discharge from the defroster vents on passenger comfort. The investigation is both experimental and computational. Full-scale tests are conducted on a current vehicle model using non-intrusive diagnostic methods. The results presented are from numerical simulations validated by experimental measurements. The numerical predictions compare well with the experimental measurements. The locations of maximum velocity and pressure, as well as width and length of re-circulation regions, are correctly predicted.

A control strategy is presented to limit the rate of heat release by Diesel Particulate Filters (DPF) during regeneration reactions between oxygen and the collected soot. Heat release is managed by limiting the oxygen supplied to the DPF, which limits the rate of the regeneration reaction. Three actuators are used to control the amount of oxygen flowing in the exhaust system: an exhaust gas re-circulation (EGR) valve, an intake throttle (ITH), and a hydrocarbon injector located upstream of the DPF in the exhaust system. The EGR valve and ITH are low-bandwidth actuators that control slowly varying changes in oxygen flow, while the hydrocarbon injector is a high-bandwidth actuator that controls the corresponding fast changes in oxygen flow.

The parameterization of variable geometry turbochargers for mean-value modeling is typically based on compressor and turbine flow and efficiency maps provided by the supplier. At low turbocharger speeds, and hence low airflows, the heat exchange via the turbocharger housing affects the temperature-based measurements of the efficiencies. Therefore, the low-speed operating regime of the turbocharger is excluded from the supplied maps and mean-value models mainly rely on extrapolation into this region, which is regularly met in emission drive cycles, and hence of significance. This paper presents experimental data from a 2.0-liter turbocharged common-rail diesel engine. While the flow maps extend from the high-speed region in a natural way, the efficiency maps are severely affected by the heat transfer effect. It is argued that this effect should be included in the mean-value model.

The relationship between engine oil formulations and catalyst performance was investigated by comparatively testing five engine oils. In addition to one baseline production oil with a calcium plus magnesium detergent system, the remaining four oils were specifically formulated with different additive combinations including: one worst case with no detergent and production level zinc dialkyldithiophosphate (ZDTP), one with calcium-only detergent and two best cases with zero phosphorus. Emissions performance, phosphorus loss from the engine oil, phosphorus-capture on the catalyst and engine wear were evaluated after accumulating 100,000 miles of taxi service in twenty vehicles. The intent of this comparative study was to identify relative trends.

Recently, several factors as advent of catalyst converter, tighter packages, calibration strategies with higher exhaust temperatures as well as corporate requirements concerning safety and passenger comfort have contributed to increase the necessity of applying concepts of heat transfer to vehicle development process, to make sure that heat rejection is properly managed in order to accomplish all these items. Traditionally, the method to verify these items has been physical tests in prototype vehicles. The most important advantage concerning this method is the accuracy of measurement results, since the prototype is usually close to the final product design level, being extremely representative. On the other hand, some disadvantages that can be pointed out in this method are concerning timing and costs involved in prototypes building process.

Increased cooling demands in Hybrid Electric Vehicles (HEVs), compactness of engine compartment, and the additional hardware under the hood make it challenging to provide an effective cooling system that has least impact on fuel economy, cabin comfort and cost. Typically HEVs tend to have a dedicated cooling system for the hybrid components due to the different coolant temperatures and coolant flow rates. The additional cooling system doubles the hardware, maintenance, cost, weight and affects vehicle fuel economy. In addition to the cooling hardware, there are several harnesses and electronics that need air cooling under the hood. This additional hardware causes airflow restriction affecting the convective heat transfer under the hood. It also affects the radiation heat transfer due to the proximity of hardware close to the major heat sources like the exhaust pipe.

A transient nonlinear Finite Element Analysis (FEA) method has been developed to simulate the inelastic deformation and estimate the thermo-mechanical fatigue life of cast iron and cast steel exhaust manifolds under dynamometer test conditions. The FEA uses transient heat transfer analysis to simulate the thermal loads on the manifold, and includes the fasteners, gasket and portion of the cylinder head. The analysis incorporates appropriate elastic-plastic and creep material models. It is shown that the creep deformation is the most single critical component of inelastic deformation for cast iron manifold ratcheting, gasket sealing, and crack initiation. The predicted transient temperature field and manifold deformation of the FEA model compares exceptionally well with two experimental tests for a high silicon-molybdenum exhaust manifold.

Maintaining adequate visibility at all times, through a vehicle windshield, is critical to the safe usage of the vehicle. The ability of the windshield defrosting and demisting system to quickly and completely melt ice on the outer windshield surface and remove mist formed on the inner surface is therefore of paramount importance. The objectives of this paper are to investigate the fluid flow and heat transfer on the windshield as well the effect of the air discharge from the defroster vents on passenger comfort. The results presented are from numerical simulations validated by experimental measurements both carried out a model and full-scale. The numerical predictions compare well with the experimental measurements at both scales. The effects of the defrosting and demisting air on occupants' comfort and safety are examined.

This study was performed by the Department of Emissions Research at Southwest Research Institute (SwRI®) in response to a request from the ASTM OPEST II (Oil Protection of Emissions Systems Test) Task Force. The objective of the study was to develop and demonstrate a preliminary catalyst oil-poisoning aging and screening procedure to evaluate and differentiate the effect of oils with varying levels of phosphorus on catalyst performance. The ultimate objective was to begin the groundwork for creating a procedure that could demonstrate the impact of engine oil formulations on catalyst performance. The oils used in this program were fully formulated oils referred to as ‘OilA’ and ‘OilB.’ OilA contained 0.11 and OilB contained 0.06 weight percent phosphorus, with both containing the same levels of ash-forming compounds. The procedure developed used a gasoline-fueled burner with an isolated oil injection subsystem.

A laboratory study was performed to assess the effectiveness of LNT+SCR systems for NOx control in lean exhaust. The effects of the catalyst system length and the spatial configuration of the LNT & SCR catalysts were evaluated for their effects on the NOx conversion, NH₃ yield, N₂O yield, and HC conversion. It was found that multi-zone catalyst architectures with four or eight alternating LNT and SCR catalyst zones had equivalent gross NOx conversion, lower NH₃ and N₂O yield, and significantly higher net conversion of NOx to N₂ than an all-LNT design or a standard LNT+SCR configuration, where all of the SCR volume is placed downstream of the LNT. The lower NH₃ emissions of the two multi-zone designs relative to the standard LNT+SCR design were attributed to the improved balance of NOx and NH₃ in the SCR zones.

High density polyethylene (HDPE) is widely used in automotive industry applications. When a specimen made of HDPE tested under cyclic loading, the inelastic deformation causes heat generated within the material, resulting in a temperature rise. The specimen temperature would stabilize if heat transfer from specimen surface can balance with the heat generated. Otherwise, the temperature will continue to rise, leading to a thermo assist failure. It is shown in this study that both frequencies and stress levels contribute to the temperature rise. Under service conditions, most of the automotive components experience low cyclic load frequency much less than 1 Hz. However, the frequency is usually set to a higher constant number for different stress levels in current standard fatigue life tests.

It is widely recognized in the automotive industry that, in very cold climatic conditions, the driving range of an Electric Vehicle (EV) can be reduced by 50% or more. In an effort to minimize the EV range penalty, a novel thermal energy storage system has been designed to provide cabin heating in EVs and Plug-in Hybrid Electric Vehicles (PHEVs) by using an advanced phase change material (PCM). This system is known as the Electrical PCM-based Thermal Heating System (ePATHS) [1, 2]. When the EV is connected to the electric grid to charge its traction battery, the ePATHS system is also “charged” with thermal energy. The stored heat is subsequently deployed for cabin comfort heating during driving, for example during commuting to and from work. The ePATHS system, especially the PCM heat exchanger component, has gone through substantial redesign in order to meet functionality and commercialization requirements.