Browse Topic: Catalytic converters

Items (188)

Performance Optimization of an Exhaust System for 4 Cylinder Engine by Implementation of Computational Fluid Dynamics, Acoustic and Thermal Analysis

2022-01-076503/29/2022

The engine system requirements have changed from being focused only on delivering engine power to now having to meet environmental emission standards. The exhaust system collects exhaust gases from the combustion cylinders, eliminates dangerous pollutants, decreases noise, and discharges the purified exhaust gases at a safe distance from the vehicle's occupants. Designs of lightweight models for exhausts were always aimed at using newer lighter materials. As the design of an exhaust is more or less fixed, this approach is hardly profitable anymore. The most important components of an exhaust system are the exhaust manifold, the catalytic converter, the muffler, the resonator and connecting all of them together are connecting exhaust pipes. In this paper, the optimization of the various elements of 4 cylinder 1.8L engine exhaust system is carried out with the help of analysis software ANSYS 19.2 workbench, by performing ‘Steady State Thermal Analysis’, ‘Acoustic Analysis’ and simulating

Aiyan, Mohammed, Sagar, S Sumanth, Raghav S, Sanjay

Investigations of Process and Component Parameters for the Number of Particles and Size Distribution of a Supercharged DI-SI Engine

2022-01-070003/29/2022

Due to the short mixture formation times in the direct injection of modern gasoline engines, there is an increase in the emission of undesirable particle emissions in gasoline engines. As a result of previous studies with a portable emission measurement system (PEMS) of raw emissions and cleaned emissions, the particle number (PN) of the sampling point after the catalyst was higher than before the catalyst at the same process parameters and engine operating points. Based on this reproducible phenomenon, several theories were proposed. The theories set up dealt on the one hand with the question of process control with regard to the formation of particles, but also fundamentally with the question of whether conventional exhaust gas aftertreatment systems (3-way catalytic converters) are suitable for influencing the number of particles. In addition, studies of the oil consumption via the blow-by system and its influence on particle emissions also played a role. To verify these theories

Dost, Tobias, Schambach, Ricardo, Getzlaff, Joern

Performance Optimisation of an Exhaust System for 4 Cylinder Engine by Implementation of Computational Fluid Dynamics, Acoustic and Thermal Analysis

2022-01-067703/29/2022

Aiyan, Mohammed, Raghav S, Sanjay, Sagar, S Sumanth

Regulatory Norms and effect on transmission component validation

2021-26-046009/22/2021

With the advent of BS VI regulations, automotive manufacturers are required to innovate the powertrains, fuel systems, exhaust and its after treatment systems to meet the regulatory requirements. The exhaust regulations can be met either by reducing the exhaust gases being generated by the engine (attacking the source) or by treating the exhaust gases in after treatment devices. The choice of the opted system varies with the manufacturer. The after-treatment devices such as catalytic converters are generally mounted in the engine compartment to take advantage of high temperature of exhaust gases to yield the reactions. Such an arrangement imposes a lot of thermal load on the peripheral components such as gearshift cables, bearings, oil seals, driveshafts etc. Thermal shields or thermal sleeve are used to address thermal issue and to protect transmission components. System level validation test requirement of transmission need to be re-visited to considering change in environmental

Tongaonkar, Yogesh Manohar, Patel, Hiral, Tendulkar, Vishveshvar, Bhosale, Vikas, halingale, Amol

Three-way catalyst model development using physical and machine learning methods for engine control design purposes

2021-01-122109/21/2021

Gasoline engine control strategies ensure a combustion control around stoichiometry. That is because the three-way catalytic converter allows CO and HC oxidation under lean operating conditions while ensuring NOx reduction for rich mixtures. In case of engine malfunction, the controller must adapt to compensate for potential torque losse and other critical attributes, potentially leading to significant deviation of the fuel-air mixture richness from stoichiometry and larger emission levels. Therefore, during development of the engine fault diagnostics the impact on the pollutant emissions must be considered. In this paper, a model-based development process is proposed. It is based on system simulation modelling techniques, where a complete exhaust line is represented in order to predict tail-pipe emissions under stoichiometric, lean and rich conditions, for engine control design purposes. Two different modelling approaches are applied and evaluated in this paper. First, a physics-based

LOUSSAIEF, Sana, Akhmetov, Yerlan, GROISIL, Melanie, Takahashi, Daisuke, Kuhara, Masaki, Isobe, Yoshiki, Mas, Peter

SYMPHONY in the key of C8

20AUTP10_0310/01/2020

Tenneco and GM solve multiple technical challenges to engineer the mid-engine Corvette's sweet-sounding active exhaust system. Few things in the automotive space are more soul-stirring than the sound of a V8 engine - at wide-open throttle, or top-gear cruising, or at any combination of engine speed and load in between. For Chevrolet Corvette enthusiasts, engine sound quality is Holy Grail stuff. But the Vette's classic roar is just one piece of an aural signature that has grown increasingly sophisticated in the car's last two (C7 and C8) generations. “Exhaust note is part of the Corvette's DNA, but the car also must meet pass-by noise laws and various global-market sound regulations,” observed Dmitri Konson, VP of global clean air engineering at Tenneco, which supplies the complete cold-side exhaust (from the catalytic converter to the exhaust tips) for the 2020 C8 Stingray and components for the LT2 V8. However, acoustics engineering isn't only about numbers and curves, Konson noted

Brooke, Lindsay

EDITORIAL: A restart into the unknown

20AUTP05_0405/01/2020

The global auto industry is gradually restarting. But going where? The COVID-19 crisis is leaving deep fiscal scars to add to the human toll. Individuals, businesses and even entire economies eventually will recover, but in an auto sector already in the throes of vast structural change, the COVID factor could have a much longer-lasting impact. Maybe not all of it has to be negative.

Visnic, Bill

Integration of Sensitivity Analysis and Design for Six Sigma (DFSS) Methodology into Transient Thermal Analysis

2020-01-138904/14/2020

In this paper we present an integrated approach which combines analysis of the effect of simultaneous variations in model input parameters on the component or system temperatures. The sensitivity analysis can be conducted by varying model input parameters using specific values that may be of interest to the user. The alternative approach is to use a structured set of parameters generated in the form of DFSS DOE matrix. The matrix represents a combination of simulation conditions which combine the control factors (CF) and noise factors. CF’s are the design parameters that the engineer can modify to achieve a robust design. Noise factors include parameters that are outside the control of the design engineer. In automotive thermal management, noise factors include changes in ambient temperature, exhaust gas temperatures or aging of exhaust system or heat shields for example. The integrated approach, presented in this paper, provides powerful tools that can significantly reduce the total

El-Sharkawy, Alaa, Sami, Amr, Arora, Dipan, Hekal, Abd El-Rahman

Heat Transfer Analysis of Catalytic Converters during Cold Starts

2019-24-016309/09/2019

The transient heat transfer behavior of an automotive catalytic converter has been simulated with OpenFOAM in 1D. The model takes into consideration the gas-solid convective heat transfer, axial wall conduction and heat capacity effects in the solid phase, but also the chemical reactions of CO oxidation, based on simplified Arrhenius and Langmuir-Hinshelwood approaches. The associated parameters are the results of data in literature tuned by experiments. Simplified cases of constant flow rates and gas temperatures in the catalyst inflow have been chosen for a comprehensive analysis of the heat and mass transfer phenomena. The impact of inlet flow temperatures and inlet flow rates on the heat up characteristics as well as in the CO emissions have been quantified. A dimensional analysis is proposed and dimensionless temperature difference and space-time coordinates are introduced. Using this suitably modified coordinates, for the case of negligible axial solid conduction, computed solid

Papetti, Viola, Dimopoulos Eggenschwiler, Panayotis, Della Torre, Augusto, Montenegro, Gianluca, Onorati, Angelo, Koltsakis, Grigorios

Optimization of Catalytic Converter Design to Improve Under-Hood Thermal Management

2019-01-126304/02/2019

The Catalytic Converter along with the inlet pipe and heat shields are part of the exhaust system that emits powerful heat to the surrounding components. With increasing need for tight under-hood spaces it is very critical to manage the heat emitted by the exhausts that may significantly increase temperature of surrounding components. In this paper a design methodology for catalytic converter has been applied which optimizes the design of the catalytic converter to reduce the surface temperature. The exhaust surface temperature is simulated as a function of time to account for transient effects. The simulation also considers various duty cycles such as road load, city traffic and grade driving conditions. To control the heat output of the exhaust system to the surrounding components different materials and properties of catalytic converter have been considered to reduce radiative heat transfer. The most influential design factors for the catalytic converter which affect the surface

El-Sharkawy, Alaa, Arora, Dipan, Huxford, Michael W.

High-Performance Rear- and Mid-Engine Vehicle Exhaust System Temperatures

2018-01-143604/03/2018

Hot surface ignition of combustible material is a known cause of vehicle fires. Although the detailed mechanisms of hot surface ignition are highly complex, the surface temperature is known to play a crucial role in this process. There has been limited previous work in the literature on this topic, much of which has focused on engine or exhaust system surface temperatures of the most common types of passenger vehicles. Also, much of this work was done in an unrepeatable manner and suffered from measurement technique induced errors. The focus of the present work is on repeatable and low measurement technique induced error temperature measurements of exhaust system surface temperatures of rear- and mid-engine sports cars. Temperature measurements were made at several points along the exhaust systems of vehicles both with and without turbo chargers on a 5-mile oval track. The exhaust system surface temperatures were examined under conditions of transient acceleration and steady-state

Papageorge, Michael, Colwell, Jeff

Thermo-Mechanical Fatigue Testing of Welded Tubes for Exhaust Applications

2018-01-009004/03/2018

Selected ferritic stainless steel sheets for exhaust applications were tested under thermo-mechanical fatigue (TMF) condition in the temperature range of 400-800 °C with partial constraint. Straight welded tubes were used as the testing coupons to withstand large compression without buckling, and to understand the effect of welding as well. Repeated tests confirmed the observed failure scenario for each material type. The hysteresis loop behaviors were also simulated using the mechanism-based integrated creep and fatigue theory (ICFT) model. Although more development work is needed, for quick material screening purpose this type of testing could be a very cost effective solution for materials and tube weld development for exhaust applications.

Quan, Guangchun, Wu, Xijia, Lafleur, Luc, zhang, Zhong

Reducing Harmful Emissions of the Vehicular Engine by Rapid After-Start Heating of the Catalytic Converter Using Thermal Accumulator

2018-01-078404/03/2018

The article examines the peculiarities of evaluating the vehicular engine harmful emissions in different heating modes when using thermal development system of the catalytic converter within phase-transitional thermal accumulators. The system under review uses thermal energy from different sources of the vehicular engine during its operation to accumulate it in thermal accumulators. The functional scheme of thermal development of the “vehicular engine - thermal accumulator - catalytic converter” system is shown. The functional scheme takes into account fuel consumption, mechanical energy and harmful emissions when operating the vehicular engine equipped with the exhaust gases cleaning system and the thermal development system with phase-transitional thermal accumulator. The article shows main mathematical dependencies to describe the processes of thermal development of the vehicular engine and the catalytic converter when using thermal development system with phase-transitional thermal

Gritsuk, Igor V., Mateichyk, Vasyl, Tsiuman, Mykola, Gutarevych, Yurii, Smieszek, Miroslaw, Goridko, Nataliia

FEA-Based Simulation of Exhaust Hanger Forces

2018-01-128804/03/2018

Exhaust systems can be a source of vibrations that transmit inside the vehicle through the exhaust hangers. These vibrations are caused by engine excitations under acceleration. During the upfront development stage, it is important to predict accurately the forces of the exhaust hangers in order to drive a robust exhaust system design and prevent objectionable noise and vibrations inside the vehicle. This paper describes an FEA-based simulation method to predict the exhaust hanger forces. It demonstrates the effect of temperature on the exhaust dynamic behavior and its importance for an accurate prediction of the exhaust hanger forces.

Xu, Zefang, Gummadi, Nagesh, Woytowich, Daniel, Zouani, Abdelkrim

Q&A: Dr. Abhaya Datye, Distinguished Professor, Department of Chemical and Biological Engineering, University of New Mexico, Albuquerque

TBMG-2870504/01/2018

Researchers at Washington State University, Pacific Northwest National Laboratory, and the University of New Mexico have created a catalyst capable of reducing pollutants at the lower temperatures expected in advanced engines. Their work presents a new way to create a more powerful catalyst while using smaller amounts of platinum — the most expensive component of emission-control catalysts.

Self-Healing, Self-Lubricating Tribofilm

TBMG-2769710/01/2017

Tribologists have developed a diamond-like film that is generated by the heat and pressure of an automotive engine. The ultra-durable, self-lubricating tribofilm — a film that forms between moving surfaces — can be made to develop self-healing, diamondlike carbon (DLC) tribofilms. The film generates itself by breaking down the molecules of the lubricating oil, and can regenerate the tribofilm as it is worn away.

Vehicle Fires Resulting from Hot Surface Ignition of Grass and Leaves

2017-01-135403/28/2017

One potential fire ignition source in a motor vehicle is the hot surfaces on the engine exhaust system. These hot surfaces can come into contact with combustible and flammable liquids (such as engine oil, transmission fluid, brake fluid, gasoline, or Diesel fuel) due to a fluid leak, or during a vehicle collision. If the surface temperature is higher than the hot surface ignition temperature of the combustible or flammable liquid in a given geometry, a fire can potentially ignite and propagate. In addition to automotive fluids, another potential fuel in post-collision vehicle fires is grass, leaves, or other vegetation. Studies of hot surface ignition of dried vegetation have found that ignition depends on the type of vegetation, surface temperature, duration of contact, and ambient conditions such as temperature and wind speed. Ignition can occur at surface temperatures as low as 300 °C, if the vegetation is in contact with the surface for 10 minutes or longer. At surface temperatures

Morse, Timothy, Cundy, Michael, Kytomaa, Harri

Methodology for the Effective Stabilization of Tin-Oxide-Based Oxidation/Reduction Catalysts

TBMG-2634902/01/2017

NASA Langley researchers, in work spanning more than a decade, have developed a portfolio of technologies for low-temperature gas catalysis. Originally developed to support space-based CO2 lasers, the technology has evolved into an array of performance capabilities and processing approaches, with potential applications ranging from indoor air filtration to automotive catalytic converters and industrial smokestack applications. The technology has been used commercially in systems that provide clean air to racecar drivers, as well as incorporated into commercially available filtration systems for diesel mining equipment. Backed with extensive research on these technologies, NASA welcomes interest in the portfolio for other commercial and industrial applications.

Experimental and Numerical Analysis for a Urea-SCR Catalytic Converter

2016-01-097304/05/2016

Urea-SCR (Selective Catalytic Reduction) systems are getting a lot of attention as the most promising NOx reduction technology for heavy-duty diesel engine exhaust. In order to promote an effective development for an optimal urea-SCR after-treatment system, it is important to clarify the decomposition behavior of the injected urea and a detailed reaction chemistry of the reactants on the catalyst surface in exhaust gases. In this paper we discuss experimental and numerical studies for the development of a numerical simulation model for the urea-SCR catalyst converter. As a first step, in order to clarify the behavior of reductants in an urea-SCR converter, two types of diagnostic technique were developed; one is for measuring the amount of NH3, and the other is for measuring the amount of total reductants including unreacted urea and iso-cyanic acid. These techniques were applied to examine the behavior of reductants at the inlet and inside the SCR converter. This revealed i) urea to

Yamauchi, Takafumi, Takatori, Yoshiki, Fukuda, Koichiro, Maruyama, Masatoshi

Optimal Energy and Emission Management of a Diesel Hybrid Electric Vehicle Equipped with a Selective Catalytic Reduction System

2015-24-254809/06/2015

This paper deals with the problem of obtaining the optimal energy and emission management strategy for a diesel hybrid electric vehicle. The vehicle is assumed to be equipped with a selective catalytic reduction device for the removal of harmful NOx emissions. The authors present a model-based procedure: The energy flows of the hybrid vehicle are modelled in a standard way, while the engine-out emissions are calculated based on a temperature-corrected engine map. For the simulation of the SCR system a combination of two existing first-principle physical models is used. The optimal energy and emission strategy for a given driving cycle is then obtained using dynamic programming. In terms of results, three case studies are presented. One case study illustrates the trade-off between fuel consumption and tailpipe NOx emissions for various relative weights of these objectives. The second case study investigates the influence of the size of the SCR system on fuel consumption and tailpipe NOx

Tschopp, Florian, Nüesch, Tobias, Wang, Mu, Onder, Christopher

Influence of Linear and Parabolic Elements in Structural Rigidity of Converter Mounting Brackets

2015-01-132604/14/2015

Generation of discretization with prescribed element sizes are adapted to the geometry. From the rules of thumb, for a complicated geometry it is important to select the reasonable element order, shapes and size for accurate results. In order to that, this paper describes the influence of elemental algorithm of the catalytic converter mounting brackets. Brackets are main source of mounting of various systems mainly intake and exhaust in the engine. In hot end exhaust system, a bracket design plays a vital role because it has to withstand heavy structural vibrations without isolation combined with thermal loads. Bracket design and stiffness determines the whole catalytic converter system's rigidity. So, here discretization of converter brackets by linear and parabolic elements is studied with different elements types and compared. The study shows disparity in the structural accuracies of the brackets in each of elemental orders respect to the element shapes i.e. in the stiffness and

Rajadurai, Sivanandi, Mani, Guru Prasad, Raja, Kavin, Mohan, Sundaravadivelu

The Effects of Diesel Oxidation Catalyst on Particulate Emission of Ethanol-Biodiesel Blend Fuel

2014-01-273010/13/2014

Because of its cleanness and renewability, biodiesel has a great potential as the alternative of diesel fuel to confront with the increasing energy crisis and environment pollution. In this study, diesel oxidation catalyst (DOC) was used to reduce the typical regulated emission and particulate emission. The combined method of fuel design concept with diesel oxidation catalyst was applied in this study. DOC with Pt catalyst was equipped in the engine test bench in this study. The effects of DOC on diesel engine particulate emission fueled with Euro V diesel fuel, biodiesel and ethanol-biodiesel blends were investigated in this study. It was found that DOC seemed have no effects on NOx emission, while it could improve the oxidation reaction from NO to NO2. In the section of particulate emission, DOC could reduce the particulate mass and number concentration, especially in the range of smaller diameter particles. The SOF could be reduced effectively with DOC. With the increase of ethanol

Zhu, Lei, zhang, Wugao, Huang, Zhen, Fang, Junhua

Partial Controlled Canning for Thin Wall and Ultra Thin Wall Substrates - A New Approach

2014-01-234809/30/2014

The trend lately has shifted towards usage of thin wall and ultra-thin wall substrates. This change has come to existence due to the increased acting surface area available in these substrates. However these types of substrates have reduced isostatic strength comparatively, reducing its canning durability. This phenomenon has induced a new canning methodology which shall not disturb the substrate integrity during canning and also perform effectively to the requirements. This can be achieved by controlled canning which includes a huge investment and so a new methodology has been devised using the available resources and a partial controlled canning process is established and verified for canning performance and found to be effective. The paper shall include the procedural explanation and a set of results obtained by the new methodology to support its effectiveness.

Rajadurai, Sivanandi, Krishnan, Prakash, Sridharan, Naveen, Sethuramasubramaniyam, Manimaran

Catalyst for Treatment and Control of Post-Combustion Emissions

TBMG-1990406/01/2014

Emissions from fossil-fuel combustion contribute significantly to smog, acid rain, and global warming problems, and are subject to stringent environmental regulations. These regulations are expected to become more stringent as state and regional authorities become more involved in addressing these environmental problems. Better systems are needed for catalytic control.

Thermal Analysis of the Exhaust Line Focused on the Cool-Down Process

2014-01-065504/01/2014

At the engine restart, when the temperature of the catalytic converter is low, additional fuel consumption would be required to warm up the catalyst for controlling exhaust emission.The aim of this study is to find a thermally optimal way to reduce fuel consumption for the catalyst warm up at the engine restart, by improving the thermal retention of the catalytic converter in the cool down process after the previous trip. To make analysis of the thermal flow around the catalytic converter, a 2-D thermal flow model was constructed using the thermal network method. This model simulates the following processes: 1) heat conduction between the substrate and the stainless steel case, 2) heat convection between the stainless steel case and the ambient air, 3) heat convection between the substrate and the gas inside the substrate, 4) heat generation due to chemical reactions. The points to be especially noted are: a) in the cool down process, free convection of the gas inside the substrate was

Hosoi, Akihito, Morita, Atsushi, Suzuki, Naoto

Systematic Optimization of an Exhaust System to Meet Noise Radiation Criteria at Idle

2014-01-000604/01/2014

Exhaust noise is a major contributor to the radiated noise level of a vehicle, especially at idle. The radiated noise level has to meet a certain criteria based on regulation and consumer demand. In many cases, the problem appears after the vehicle is manufactured and the tailpipe noise measurement is performed indicating a high noise level that needs to be reduced. This paper describes one of those cases where the radiated noise level of a certain passenger car at idle was required to be reduced by 6 dB(A). The exhaust system consists of one main muffler and one auxiliary muffler. A 1D two-port model of the exhaust system including the two mufflers was built using commercial software. This model was validated against the measurement of the two-port matrix of both mufflers. The model was then used together with tailpipe noise measurements to estimate the characteristics of the source strength and impedance. Using a 1D model of the complete system, it was possible to propose several

Elnady, Tamer, Abom, Mats, Yang, Yong

Muffler Sound Development Using Analysis of Acoustic Source of Engine Exhaust System

2014-01-002604/01/2014

In order to achieve the proper automobile interior sound, the tailpipe noise of the exhaust system must be considered as a main contributor. This paper describes a study of the achievement of dynamic sound quality through exhaust system design. Firstly, we determined the vehicle's interior sound quality and established a target sound using a subjective assessment of 10 benchmark vehicles. The exhaust noise target is determined by means of transfer path analysis focusing on the noise source and how it's impacted by the muffler design. The exhaust system is commonly modeled as a combination of source strength and impedance. We obtained the source character by the wave decomposition method using two microphones and six loads ultimately leading to an optimized design of the inner muffler structure. Based on this study, we achieved dynamic interior sound and improved exhaust system performance.

Han, HakSon, Park, ChulMin, Heo, JeongHoi, Kang, Sang Kyu

The Study on Catalyst Light-Off Time and Emission Reduction of Turbo Gasoline Direct Injection EU5 Exhaust System

2013-01-260810/14/2013

The future powertrain development is characterized by better fuel economy. To meet this, using turbo system in the engine is becoming more frequent in the vehicle development. But using turbo in the engine is only good for power and fuel economy, and not good for emission. That is because the turbo equipped engine loses lots of heat energy at the cold start due to the turbo mass. And thus for turbo engine, it is required to apply the technologies to shorten the catalyst light-off time to reduce the exhaust emissions. Especially when the turbo equipped vehicle is tested on NEDC cycle which is tested on urban low speed cycle at the start of the cycle, its emission is too much to meet the Euro5 regulation. This paper investigates the successful ways to reduce the catalyst light-off time and exhaust emissions to meet the EU5 emission regulation in turbo gasoline direct injection(Turbo GDI) engine. So we do the comprehensive emission tests like increasing the precious metal and cell density

Jang, ChunSoon, Kim, Sangbeom, Park, Cheolho

Tenneco

13OFHD0613_1106/13/2013

Technology meets regulatory challenges Tenneco entered the clean air business in the mid-1970s, with the introduction of catalytic converters to passenger cars, driven by the Clean Air Act of 1970. This initial act led, in subsequent decades, to a series of regulations and amendments that imposed stricter emissions standards and broadened coverage from gasoline-powered passenger vehicles to include diesel trucks and other machinery employed both on- and off-highway. This regulatory evolution sparked the corresponding development of increasingly sophisticated technology to control emissions at prescribed levels, which has enabled Tenneco to expand its emissions control business beyond light vehicles. Today, Tenneco supplies diesel aftertreatment systems to leading global manufacturers of engines and commercial equipment for companies that include Caterpillar/Perkins, John Deere, Deutz, Scania, MAN, and Kubota.

Jackson, Tim

New York - General Provisions/Emission Standards for Motor Vehicles

RS-BNA-NOV_12_0411/28/2012

Final rule of the Department of Environmental Conservation amends regulations under 6 NYCRR 200 and 218 and repeals regulations under 6 NYCRR 252 regarding emission standards for motor vehicles. The rule incorporates California's new and amended standards for low-emission vehicles, zero-emission vehicles, greenhouse gas emissions, environmental performance labels, catalytic converters, and warranty requirements. The rule also deletes existing requirements for environmental performance labels. The rule is effective Dec. 9, 2012, except for provisions under 6 NYCRR 218-7.2(c), which are effective June 1, 2013. Contact: Jeff Marshall; DEC; (518-402-8292)

Tuning the Standard SCR Reaction Kinetics to Model NO Conversion in a Diesel Engine Exhaust SCR Catalyst System Under Steady State Conditions in 1D and 3D Geometries Using Ammonia Gas as the Reductant

2012-01-163609/10/2012

Removal of NOx from lean diesel exhaust can be achieved by the use of selective catalytic reduction technology. The supplied reductant is often ammonia, either as urea or as ammonia gas released from a storage medium. Experiments have been carried out on an engine test rig run to steady state conditions using NOx composed mainly of NO, with ammonia gas as the reductant. This was essentially a 1D study because a long 10 degree diffuser was used to provide uniform temperature and velocity profile to the SCR catalyst brick in the test exhaust system. Tuning of the standard reaction, the NO SCR reaction, in a kinetic scheme from the literature and adjustment of the ammonia adsorption kinetics achieved improved agreement between the measurements and CFD simulations. This was carried out for studies at exhaust gas temperatures between 200 and 300°C. The effect of diffuser geometry upstream of the SCR catalyst on NOx conversion was then investigated experimentally using a 180 degree sudden

Benjamin, S. F., Gall, M., Roberts, C. A.

New York - General Provisions/Emission Standards for Motor Vehicles

RS-BNA-JUL_12_0208/01/2012

Proposed rule of the Department of Environmental Conservation amends regulations under 6 NYCRR 200 and 218, and repeals regulations under 6 NYCRR 252 regarding emission standards for motor vehicles. The rule incorporates California's new and amended standards for low-emission vehicles, zero-emission vehicles, greenhouse gas emissions, environmental performance labels, catalytic converters, and warranty requirements. The rule also deletes existing requirements for environmental performance labels. Hearings are scheduled for Sept. 17, 19, and 20, 2012, in Avon, Albany, and Long Island City, respectively. Comments are due Sept. 27, 2012. Contact: Jeff Marshall; DEC; (518-402-8292)

SAE Powertrain & Energy 2012-07-25

12DPE072507/25/2012

The row about rare earths Rare-earth elements are key to applications as varied as traction motors, catalytic converters, and wind turbines, but high prices and supply shortages have the auto industry grappling with design changes and other alternatives.

The Passive Acoustic Effect of Automotive Catalytic Converters

2011-24-021909/11/2011

For the last couple of decades, catalytic converters (CC) have become a standard part of the internal combustion engine exhaust systems. Besides reducing toxic components in exhaust gases, catalytic converters can have a certain effect on the acoustic performance of the exhaust system. In this paper the sound transmission and attenuation in the catalytic converters has been investigated. A catalytic converter is known to have two distinct acoustic effects: the reactive effect originating from the acoustic wave reflections caused by cross-sectional area changes within the unit and the resistive effect which results in the acoustic wave dissipation caused by visco-thermal losses. The flow resistance in the narrow tubes in the catalytic converter element results in frequency dependent dissipative effects on the transmitted sound. An experimental investigation on engine catalytic converters treated as acoustic two-ports is carried out. The acoustic behavior of the catalytic converters is

Lavrentjev, Jüri, Rämmal, Hans, Tiikoja, Heiki

Investigation of the Acoustic Performance of After Treatment Devices

2011-01-156205/17/2011

Diesel engines produce harmful exhaust emissions and high exhaust noise levels. One way of mitigating both exhaust emissions and noise is via the use of after treatment devices such as Catalytic Converters (CC), Selective Catalytic Reducers (SCR), Diesel Oxidation Catalysts (DOC), and Diesel Particulate Filters (DPF). The objective of this investigation is to characterize and simulate the acoustic performance of different types of filters so that maximum benefit can be achieved. A number of after treatment device configurations for trucks were selected and measured. A measurement campaign was conducted to characterize the two-port transfer matrix of these devices. The simulation was performed using the two-port theory where the two-port models are limited to the plane wave range in the filter cavity. These models are implemented in SIDLAB Software for the simulation of low frequency sound propagation in ducts, and SIDLAB was used to predict the transfer matrix of the tested

Elnady, Tamer, Elsaadany, Sara, Herrin, D. W.

Optimizing Exhaust System Design To Minimize Shipping Costs

2011-01-125604/12/2011

The design of an existing GM exhaust system is analyzed for possible design modifications that may result in lower shipping costs between the supplier facility that manufactures the exhaust system and the assembly plant that installs the system. Investment, changes in piece cost, and other factors are examined in order to determine design changes based upon a rate of return on the investment.

Loveless II, Benjamin Ward

Acoustic Analysis of Small Engine Catalytic Converters

2010-32-002209/28/2010

Today, catalytic converters are widely used in small engine exhaust systems to reduce pollutants. Besides reducing harmful pollutants, these devices have a significant effect on the acoustical performance and the pressure drop of the engine exhaust system. A catalytic converter is known to have two distinct acoustic effects: the reactive effect originating from the acoustic wave reflections caused by cross-sectional area changes within the unit and the resistive effect which results in the acoustic wave dissipation caused by viscous losses. The pressure drop in the narrow tubes in the catalytic converter element results in frequency dependent resistive effects on the transmitted sound. In this paper the passive acoustic effect which treats the sound attenuation in the catalytic converters has been investigated. An experimental investigation on small engine catalytic converters treated as acoustic two-ports is carried out. A novel test facility, recently set up in TUT for acoustic

Lavrentjev, Jüri, Rämmal, Hans

Investigation into the Role of Catalytic Converters on Tailpipe-out Nano-Scale Particulate Matter from Gasoline Direct Injection Engine

2010-01-157205/05/2010

This study investigated the role of catalytic converters on tailpipe-out, nano-scale particulates from a Direct-Injection Spark-Ignition (DISI) gasoline engine. The test engine used for this research was a 1.6 litre, wall-guided DISI, turbocharged, intercooled, in-line 4-cylinder, Euro- IV engine. Spectral density of the particles in the exhaust stream before and after the catalytic converter was measured and was split into four size ranges: 5-10nm, 10-50nm, 50-100nm and 100-1000nm diameter for the sake of analysis. These four size ranges represent both nucleation mode (5-50nm) and accumulation mode (50-1000nm) particulates. The study found that for lower engine operating speeds, i.e. 1600rpm, the catalytic converter had a significant effect on the total number of 5-10 and 10-50nm diameter particles. At certain loading conditions the catalytic converter removed up to 60% of the 5-10nm particles and up to 22% of the 10-50nm particles. However, at higher operating speed such as 3200rpm

Whelan, Ian, Samuel, Stephen, Hassaneen, Ahmed

Method of Heating a Foam-Based Catalyst Bed

TBMG-636612/01/2009

A method of heating a foam-based catalyst bed has been developed using silicon carbide as the catalyst support due to its readily accessible, high surface area that is oxidation-resistant and is electrically conductive. The foam support may be resistively heated by passing an electric current through it. This allows the catalyst bed to be heated directly, requiring less power to reach the desired temperature more quickly. Designed for heterogeneous catalysis, the method can be used by the petrochemical, chemical processing, and power-generating industries, as well as automotive catalytic converters. Catalyst beds must be heated to a lightoff temperature before they catalyze the desired reactions. This typically is done by heating the assembly that contains the catalyst bed, which results in much of the power being wasted and/or lost to the surrounding environment. The catalyst bed is heated indirectly, thus requiring excessive power. With the electrically heated catalyst bed, virtually

Steady-State and Transient Motor Vehicle Exhaust System Temperatures

2009-01-001304/20/2009

One of the known causes of motor vehicle fires is hot surface ignition of combustible material that contacts engine exhaust system components. While ignition is a complicated phenomenon, the temperature of the surface is known to be an important parameter. However, little data is available in the literature concerning exhaust system temperatures, and much of this data is confounded by thermocouple attachment techniques and undocumented variations in driving conditions. In the present study, engine exhaust system temperature measurements were conducted using six test vehicles on a level, 2-mile oval test track at constant vehicle speeds ranging from 0 (idle) to 70 mph. By normalizing transient temperature curves with these steady-state temperatures along with ambient temperature, the rates at which the exhaust system components warm up and cool down are also compared. The effect of thermocouple mounting technique was evaluated by conducting identical testing with the thermocouples

Colwell, Jeff D., Biswas, Kaushik

A Novel Technology for the Inhibition of Ceramic Fiber Erosion and Promotion of Substrate Retention in Catalytic Converters

2009-01-097504/20/2009

As emission requirements become increasingly more stringent, catalytic converters are being subjected to harsher conditions. These conditions include higher temperatures, increased vibration levels, higher frequencies and more intense exhaust gas impingement on the mat mount. All of which can contribute to the mat mount erosion. Over time, this erosion can lead to catastrophic failure of the catalytic converter either from gas bypass, plugging of the substrate or the loss of substrate retention within the converter. Several technologies have been developed to reduce mat mount erosion. These technologies include; wiremesh seals, rigidizers, silica cloth edge treatment and polycrystalline edge seals which all are in use today. These erosion reduction technologies provide varying degrees of erosion protection, and each has one or more drawbacks. These drawbacks include cost, productivity, handling and overall performance. This paper discusses the merits of a novel erosion reducing edge

Watson, Mitchell, Dietz, Peter

Medical Design Advances Provide New Diagnostic and Treatment Options

TBMG-354302/01/2009

Advances in medical design are paving the way for diagnostic and treatment options that previously were thought to be impossible. Today, surgeons, emergency medical personnel, and other healthcare professionals have a myriad of tools and techniques at their fingertips to help treat disease, create better orthopedic equipment and implants, and more accurately diagnose patients. Here is only a sampling of some of these new medical design breakthroughs.

Impact of the Fast Engine Cooling of a Gasoline Engine on Exhaust Emissions and Fuel Consumption

2008-01-244110/06/2008

European regulations requires a minimum duration of 6 hours between two approval tests; however, as this duration is not sufficient for a complete engine cooling, most car manufactures use a duration of 24 hours. This higher duration implies larger cooling rooms and thus increased cost. In this work, different modes of fast cooling based on ventilators were tested in the case of a passenger car equipped with a gasoline engine. The best mode, for development but also for industrial purposes, is the one with the ventilator at the front of the vehicle with open hood and two smaller ventilators blowing in the engine. Using this cooling mode, the engine respects European regulations. A comparison between this mode of fast cooling and a mode of natural cooling of 24 hours shows that the two modes have very similar fuel consumption (expressed as CO2 emissions) and engine-out emissions of regulated pollutants (CO, HC and NOx). The tail-pipe emissions of the fast engine cooling are lower than

Zervas, Efthimios

Green engineering

OFHSEP08_0409/01/2008

The quest to alleviate environmental and efficiency pressures turns up “small” material solutions with big benefits. At the beginning of August, with crude-oil prices decreasing slightly but still above $120/barrel, the national average for on-highway diesel fuel (all types) was $4.60, according to the U.S. Energy Information Administration-$1.72 more expensive than a year ago. With record-high fuel prices, not to mention looming emissions regulations such as U.S. EPA Tier 4 Interim by 2011, “going green” is no longer just a corporate ploy to boost public perception; it is becoming essential to a company's bottom line. As a result, no technology area is exempt from R&D spending as off-highway equipment makers and their suppliers search for cleaner, lighter, more-efficient alternatives. Undoubtedly, powertrain is a top priority, with sophisticated emissions-control systems coming on board as ultra-low-sulfur diesel fuel becomes a requirement for non-road diesel engines in 2010.

Gehm, Ryan

The Deleterious Effects of Organic Binder on Intumescent Mat Mount Material

2008-01-045204/14/2008

For decades, ceramic fiber mats have been used to mechanically support substrates in catalytic converters. Intumescent mats, those that expand with heat, are composed primarily of ceramic fibers, vermiculite, and organic binder. The binder is required for manufacturing, handling, and installation. Unfortunately, under cool operating conditions, its effects on mat performance are often negative. While residual binder is not an automatic precursor to premature failure, it can amplify the effects of other factors such as gap control and vibration. As the mat mount material is heated, sections can become soft and pliable. In the absence of sufficient heat for complete binder removal, regions of the mat may become rigid during the cooling cycle. This results in a decrease in mat resiliency. Several tests can be used to show the relationship between binder level and material performance. These tests typically characterize expansion properties and pressure performance. By comparing test

Brunner, Nathan, De Rovere, Anne, Fischer, Patrick, Shirk, Ryan

Prediction of Catalytic Converter Durability Using Hot Push-out Test Methods

2008-01-143604/14/2008

Catalytic converter mechanical robustness depends on maintaining a certain range of mat pressure to firmly hold the honeycomb ceramic substrate from moving inside a catalytic converter during its service life while avoiding fracturing it in the manufacturing process. Durability, robustness and performance of the converter assembly need to be predicted for designing the mounting system parameters. This paper investigates the major factors that affect the mat holding force. An innovative substrate hot push-out test method is presented to measure the mat holding force, providing the key performance data earlier in the design cycle. DOE data along with statistical analyses are presented showing the correlation between the mat holding force and various key factors. Hot push-out test can be used to replace the current key-life testing method as a cost effective pre-screen test method that enables robust design earlier in the design cycle. It can also be used as a prediction of catalytic

Wang, Hui, Sanderson, Bobby, Koivula, Bill, Das, Niladri

Influence of Washcoat Distribution on the Performance of Diesel Oxidation Catalysts

2007-01-400710/29/2007

The assessment of tighter and tighter emission targets, and the increase of efficiency of Diesel engines is pushing towards the need of oxidation catalysts capable of high conversion performance at very low temperatures. These capabilities can be achieved only by the adoption of very high noble metal loadings (up to 140 g/ft3), which lead to very high costs. Washcoat distribution may play a key role in this context. In this paper the influence of washcoat distribution on light-off behaviour of a Diesel Oxidation Catalyst has been then investigated by means of a 3D numerical model. The model is capable of representing the coupling among flow, washcoat diffusion and detailed surface chemistry. Results state that the adoption of an optimized washcoat distribution may roughly lead to cost-savings of the order 30-40% in terms of noble metal loading.

Cordiner, S., De Simone, G., Mulone, V.

The optimization of Exhaust and Catalytic Converter System for ULEV-II using the Robust Design

2007-01-056004/16/2007

The conventional aftertreatment systems to meet the stringent ULEV-II emission regulation are usually composed of warm-up catalytic converter (WCC) and underfloor catalytic converter (UCC). However, those systems bring high cost, high back pressure, the limit of engine room for package design, and other side effects.[4] The new optimized system needs to solve these problems and to meet ULEV-II emission regulation efficiently. There are many technologies and design parameters in exhaust catalytic converter systems; exhaust manifold structure[9], exhaust gas flow distribution, location of catalytic converter, PM coating technologies[1], substrate characteristics, and volume of catalysts. It is a key factor to make a optimized robust system with those parameters and technologies described. The new optimized exhaust and Integrated Close-coupled Catalytic Converter (ICCC) system can meet ULEV-II regulation and can solve those problems of conventional system by a robust design. This study

Kim, Sangbeom, Kim, Sungkun, Park, Yongjung, Kim, Youngbum, Kim, Hyunsoo, Lee, Seungseok, Yeon, Taehun

Evaluation Technique of Two-Stroke Engine Oil for Motorcycles

2006-32-011711/13/2006

The main evaluation methods of two-stroke engine oil were standardized as the JASO (JASO: Japanese Automobile Standard Organization) method in 1993(1). After the establishment of the JASO specification, the authors executed an evaluation of various oils. As a result, it has been determined that an examination method that also evaluates the differences in demands on oil caused by regional characteristics and use conditions of the engine is necessary. Thus, the three following methods were developed. The first is a method of low-temperature detergency examination. The second is a method of low-temperature start-ability examination. The third is an exhaust port carbon blocking examination. These three examination methods are explained in full in this paper.

Kawabe, Hideaki, Takahashi, Kunio

1D Modeling of the Hydrodynamics and of the Regeneration Mechanism in Continuous Regenerating Traps

2006-01-301109/14/2006

The present work focuses on the simulation of the hydrodynamics, transient filtration/loading and catalytic/NO2-assisted regeneration of Diesel after-treatment systems. A 1D unsteady model for compressible and reacting flows for the numerical simulation of the behavior of Diesel Oxidation Catalysts (DOCs) and Diesel Particulate Filters (DPFs) has been developed. The numerical model is able to keep track of the amount of soot in the flow; the increasing of back-pressure through the exhaust system (mainly due to the Diesel Particulate Filter) can be predicted by the calculation of the permeability variation of the porous wall, as the soot particles goes inside the DPF. A sub-model for the regeneration of the collected soot has been developed: the collected particulate is oxidized by the Oxygen (O2) and by the Nitrogen Dioxide (NO2). The new approach allows to study the devices' behavior under unsteady state operating conditions, when the thermo-fluid dynamic characteristics of the

Ferrari, G., Piscaglia, F., Onorati, A.

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