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Development of a 3rd Generation SCR NH3-Direct Dosing System for Highly Efficient DeNOx

2012-06-18
In this project funded by the Bayerische Forschungsstiftung two fundamental investigations had been carried out: first a new N-rich liquid ammonia precursor solution based on guanidine salts had been completely characterized and secondly a new type of side-flow reactor for the controlled catalytic decomposition of aqueous NH3 precursor to ammonia gas has been designed, applied and tested in a 3 liter passenger car diesel engine. Guanidine salts came into the focus due to the fact of a high nitrogen-content derivate of urea (figure 1). Specially guanidinium formate has shown extraordinary solubility in water (more than 6 kg per 1 liter water at room temperature) and therefore a possible high ammonia potential per liter solution compared to the classical 32.5% aqueous urea solution (AUS32) standardized in ISO 22241 and known as DEF (diesel emission fluid), ARLA32 or AdBlue®. Additionally a guanidine based formulation could be realized with high freezing stability down to almost ?30 °C (?
Collection

Fire Safety, 2012

2012-04-13
The 9 papers in this technical paper collection focus on fire safety. Topics covered include hot surface ignition, oxidation on steel surfaces, standard tests for assessing the effectiveness of transit vehicle fire extinguishing systems, and more. The 9 papers in this technical paper collection focus on fire safety. Topics covered include hot surface ignition, oxidation on steel surfaces, standard tests for assessing the effectiveness of transit vehicle fire extinguishing systems, and more.
Collection

Automotive Lighting Technologyand Human Factors in Driver Vision and Lighting, 2012

2012-04-13
The 14 papers in this technical paper collection cover automotive lighting technology and human factors in driver vision and lighting. Topics discussed include LED design and applications, signal lighting, side view cameras, red light cameras, high dynamic range photography, and more. The 14 papers in this technical paper collection cover automotive lighting technology and human factors in driver vision and lighting. Topics discussed include LED design and applications, signal lighting, side view cameras, red light cameras, high dynamic range photography, and more.
Collection

Fire Safety, 2014

2014-04-01
This technical paper collection focuses on current developments in the fields of vehicle fire science, statistics, risks, assessment and mitigation. Papers addressing vehicle design, live-fire tests and fire investigation issues applicable to traditional, electric and alternatively fueled vehicles are included.
Journal Article

Artificial Lightning Tests on Metal and CFRP Automotive Bodies: A Comparative Study

2019-01-07
Abstract Carbon fiber reinforced plastic (CFRP) has been used in automobiles as well as airplanes. Because of its light weight and high strength, CFRP is a good choice for making vehicle bodies lighter, which would improve fuel economy. Conventional metal bodies provide a convenient body return for electric wiring and offer good shielding against electromagnetic fields. Although CFRP is a conductor, its conductivity is much lower than that of metals. Therefore, CFRP bodies are usually not useful for electric wiring. In thunderstorms, an automotive body is considered to be a Faraday cage that protects the vehicle’s occupants from the potential harms of lightning. Before CFRP becomes widely applied to automotive bodies, its electric and electromagnetic properties need to be investigated in order to determine whether it also works as a Faraday cage against lightning. In this article, CFRP and metal body vehicles were tested under artificial lightning.
Journal Article

Hewing Out Evacuation Routes for Burning Buses by Linear-Shaped Charge Jet

2019-01-25
Abstract In recent years, several buses have ignited in some cities in China, causing numerous deaths and significant property damage. However, few research studies have been conducted to deal with such accidents. Therefore, in this work, a linear-shaped charge jet with rectangular cross sections was used to hew out evacuation routes for burning buses, and the parameter design for the shaped charge jet was improved according to asymmetry limitations and human tolerance. A numerical finite element simulation model of the behavior of a jet penetrating the jambs was established using ANSYS/LS-DYNA software. The asymmetrical characteristics of an arc segment in the structure of a rectangular-shaped charge were analyzed, in addition to the influence on the deviations of the jet penetration capacity and blast injuries to occupants caused by the side effects of detonation.
Journal Article

Improving Hole Expansion Ratio by Parameter Adjustment in Abrasive Water Jet Operations for DP800

2018-09-17
Abstract The use of Abrasive Water Jet (AWJ) cutting technology can improve the edge stretchability in sheet metal forming. The advances in technology have allowed significant increases in working speeds and pressures, reducing the AWJ operation cost. The main objective of this work was to determine the effect of selected AWJ cutting parameters on the Hole Expansion Ratio (HER) for a DP800 (Dual-Phase) Advanced High-Strength Steel (AHSS) with s0 = 1.2 mm by using a fractional factorial design of experiments for the Hole Expansion Tests (HET). Additionally, the surface roughness and residual stresses were measured on the holes looking for a possible relation between them and the measured HER. A deep drawing quality steel DC06 with s0 = 1.0 mm was used for reference. The fracture occurrence was captured by high-speed cameras and by Acoustic Emissions (AE) in order to compare both methods.
Journal Article

Application of a Flow Field Based Heat Transfer Model to Hydrogen Internal Combustion Engines

2009-04-20
2009-01-1423
A realistic modeling of the wall heat transfer is essential for an accurate analysis and simulation of the working cycle of internal combustion engines. Empirical heat transfer formulations still dominate the application in engine process simulations because of their simplicity. However, experiments have shown that existing correlations do not provide satisfactory results for all the possible operation modes of hydrogen internal combustion engines. This paper describes the application of a flow field-based heat transfer model according to Schubert et al. [1]. The models strength is a more realistic description of the required characteristic velocity; considering the influence of the injection on the global turbulence and on the in-cylinder flow field results in a better prediction of the wall heat transfer during the compression stroke and for operations with multiple injections. Further an empirical hypothesis on the turbulence generation during combustion is presented.
Journal Article

1D Thermo-Fluid Dynamic Modeling of Reacting Flows inside Three-Way Catalytic Converters

2009-04-20
2009-01-1510
In this work a detailed model to simulate the transient behavior of catalytic converters is presented. The model is able to predict the unsteady and reacting flows in the exhaust ducts, by solving the system of conservation equations of mass, momentum, energy and transport of reacting chemical species. The en-gine and the intake system have not been included in the simulation, imposing the measured values of mass flow, gas temperature and chemical composition as a boundary condition at the inlet of the exhaust system. A detailed analysis of the diffusion stage triggering is proposed along with simplifications of the physics, finalized to the reduction of the calculation time. Submodels for water condensation and its following evaporation on the monolith surface have been taken into account as well as oxygen storage promoted by ceria oxides.
Journal Article

The Poisoning and Desulfation Characteristics of Iron and Copper SCR Catalysts

2009-04-20
2009-01-0900
A laboratory study was performed to assess the effects of SO2 poisoning on the NOx conversion of iron (Fe) and copper (Cu) SCR catalysts. Thermally aged samples of the catalysts were poisoned with SO2 under lean conditions. At various times during the poisonings, the samples were evaluated for NOx conversion with NO and NH3 using lean temperature ramps. The low temperature NOx conversions of both catalysts decreased by 10 to 20% after 1 to 4 hours of poisoning but were stable with continued exposure to the SO2. The poisoned Cu SCR catalyst could be desulfated repeatedly with 5 minutes of lean operation at 600°C. Initially, the poisoned Fe SCR catalyst required 5 minutes of lean operation at 750°C to recover its maximum NOx conversion.
Journal Article

Thermodynamic Analysis of SI Engine Operation on Variable Composition Biogas-Hydrogen Blends Using a Quasi-Dimensional, Multi-Zone Combustion Model

2009-04-20
2009-01-0931
In this work, a quasi-dimensional, multi-zone combustion model is analytically presented, for the prediction of performance and nitric oxide (NO) emissions of a homogeneous charge spark ignition (SI) engine, fueled with biogas-H2 blends of variable composition. The combustion model is incorporated into a closed cycle simulation code, which is also fully described. Combustion is modeled on the basis of turbulent entrainment theory and flame stretch concepts. In this context, the entrainment speed, by which unburned gas enters the flame region, is simulated by the turbulent burning velocity of a flamelet model. A flame stretch submodel is also included, in order to assess the flame response on the combined effects of curvature, turbulent strain and nonunity Lewis number mixture. As far as the burned gas is concerned, this is treated using a multi-zone thermodynamic formulation, to account for the spatial distribution of temperature and NO concentration inside the burned volume.
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