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Viewing 1 to 30 of 3905
2010-10-25
Technical Paper
2010-01-2166
Seung Yang, Kyeong Lee, Hwansoo Chong
At the current stage of engine technology, diesel engines typically require diesel particulate filter (DPF) systems to meet recent particulate emissions standards. To assure the performance and reliability of DPF systems, profound understanding of filtration and regeneration mechanisms is required. Among extensive efforts for developing advanced DPF systems, the development of effective thermal management strategies, which control the thermal runaway taking place in oxidation of an excess amount of soot deposit in DPF, is quite challenging. This difficulty stems mainly from lack of sufficient knowledge and understanding about DPF regeneration mechanisms, which need detailed information about oxidation of diesel particulate matter (PM). Therefore, this work carried out a series of oxidation experiments of diesel particulates collected from a DPF on a diesel engine, and evaluated the oxidation rates of the samples using a thermo-gravimetric analyzer (TGA).
2010-10-25
Technical Paper
2010-01-2171
Shuji Fujii, Tsuyoshi Asako
Ash accumulation is a considerable factor for long-term Diesel Particulate Filter (DPF) performance. Ash accumulation reduces the open frontal area (OFA) and plugs the surface pores. As a result, DPF back pressures with no soot (hereinafter “initial DPF back pressure”) rise. At the same time, DPF back pressures with soot (hereinafter “sooted DPF back pressure”) fall [ 1 , 2 , 3 , 4 ]. Then sooted DPF back pressures rise after the reductions of the certain ranges [ 1 , 3 , 4 ]. It is known that DPF back pressure behaviors change variously by ash loading like this. The understanding of DPF back pressure behaviors with ash accumulation is indispensable for proper after-treatment system management. Ash accumulation progresses slowly and gradually in DPF while using of vehicles. Because of the slowness, the field surveys require a few years at least.
2010-09-28
Technical Paper
2010-32-0035
Dalibor Jajcevic, Matthias Fitl, Stephan Schmidt, Karl Glinsner, Raimund Almbauer
The exhaust system design has an important influence on the charge mass and the composition of the charge inside the cylinder, due to its gas dynamic behavior. Therefore the exhaust system determines the characteristics of the indicated mean effective pressure as well. The knowledge of the heat transfer and the post-combustion process of fuel losses inside the exhaust system are important for the thermodynamic analysis of the working process. However, the simulation of the heat transfer over the exhaust pipe wall is time consuming, due to the demand for a transient simulation of many revolutions until a cyclic steady condition is reached. Therefore, the exhaust pipe wall temperature is set to constant in the conventional CFD simulation of 2-stroke engines. This paper covers the discussion of a simulation strategy for the exhaust system of a 2-cylinder 2-stroke engine until cyclic steady condition including the heat transfer over the exhaust pipe wall.
2010-10-25
Technical Paper
2010-01-2089
M. P. Sturgess, S. F. Benjamin, C. A. Roberts
Modeling of SCR in diesel exhaust systems with injection of urea spray is complex and challenging but many models use only the conversion observed at the brick exit as a test of the model. In this study, the case modeled is simplified by injecting ammonia gas in nitrogen in place of urea, but the spatial conversion profiles along the SCR brick length at steady state are investigated. This is a more rigorous way of assessing the ability of the model to simulate observations made on a test exhaust system. The data have been collected by repeated engine tests on eight different brick lengths, all which were shorter than a standard-sized SCR. The tests have been carried out for supplied NH₃ /NOx ratios of a 1.5, excess ammonia, a 1.0, balanced ammonia, and a 0.5, deficient ammonia. Levels of NO, NO₂ and NH₃ have been measured both upstream and downstream of the SCR using a gas analyzer fitted with ammonia scrubbers to give reliable NOx measurements.
2010-10-25
Technical Paper
2010-01-2126
Alexander Sappok, Leslie Bromberg, James E. Parks, Vitaly Prikhodko
Accurate knowledge of diesel particulate filter (DPF) particulate matter (PM) loading is critical for robust and efficient operation of the combined engine-exhaust aftertreatment system. Furthermore, upcoming on-board diagnostics regulations require on-board technologies to evaluate the status of the DPF. This work describes the application of radio frequency (RF) - based sensing techniques to accurately measure DPF particulate matter levels. A 1.9L GM turbo diesel engine and a DPF with an RF-sensor were studied. Direct comparisons between the RF measurement and conventional pressure-based methods were made. Further analysis of the particulate matter loading rates was obtained with a mass-based total PM emission measurement instrument (TEOM) and DPF gravimetric measurements.
2010-04-12
Journal Article
2010-01-0557
Gregory Austin, Jeffrey Naber, John H. Johnson, Chris Hutton
Active regeneration experiments were performed on a production diesel aftertreatment system containing a diesel oxidation catalyst and catalyzed particulate filter (CPF) using blends of soy-based biodiesel. The effects of biodiesel on particulate matter oxidation rates in the filter were explored. These experiments are a continuation of the work performed by Chilumukuru et al., in SAE Technical Paper No. 2009-01-1474, which studied the active regeneration characteristics of the same aftertreatment system using ultra-low sulfur diesel fuel. Experiments were conducted using a 10.8 L 2002 Cummins ISM heavy-duty diesel engine. Particulate matter loading of the filter was performed at the rated engine speed of 2100 rpm and 20% of the full engine load of 1120 Nm. At this engine speed and load the passive oxidation rate is low. The 17 L CPF was loaded to a particulate matter level of 2.2 g/L.
2010-04-12
Journal Article
2010-01-0559
Keld Johansen, Gurli Mogensen, Damien Mey, David Pinturaud
Silicon carbide diesel particulate filter (DPF) is now recognized as the most effective and robust way to reduce not only the mass but also the number of emitted particles on diesel passenger cars. Widespread use of expensive catalytic platinum-containing coatings has contributed to increased harmful NO₂ emissions. A novel low-cost palladium-base metal coating, BMC-211, was developed which assists soot regeneration by oxygen transport and which actively removes NO₂ still having comparable passive and active soot regeneration properties. The novel coating was tested against a traditional commercial platinum coating on a modern series-produced car, on chassis dynamometer and on engine test bench.
2010-04-12
Technical Paper
2010-01-0560
Ted N. Tadrous, Kevin Brown, Paul Towgood, Campbell McConnell
Active regeneration of diesel particulate filters is becoming essential for performance longevity given the diversity of duty cycles and engines' operating behaviors for existing and newer engines. The Syngas containing hydrogen and carbon monoxide from diesel fuel and air produced by the non-catalytic Syngas Generator is potential candidate to actively enhance the regeneration efficiency of diesel particulate filters. The Syngas is utilized to create an exothermic condition over a pre-catalyst to the DPF to bring exhaust gas temperature from as low as 200°C to 650°C to enable a sustained DPF regeneration process. The Syngas is introduced to an inlet assembly which is divided into 4 quadrants so the full Syngas is mixing with a quarter of the exhaust flow and regenerating one DPF quadrant at a time. The Syngas DPF system is designed to operate seamlessly and is transparent to the vehicle operator.
2010-04-12
Technical Paper
2010-01-0562
Kun chul Park, Soonho Song, Kwang min Chun
Diesel particulate filter (DPF) systems are being used to reduce the particulate matter emissions of diesel vehicles. The DPF should be regenerated after certain driving hours or distance to eliminate soot in the filter. The most widely used method is active regeneration with oxygen at 550~650°C. Fuel penalty occurs when the exhaust gas temperature is increased. The low temperature oxidation technique is needed to reduce fuel consumption. In this study, we found that hydrogen could be used to decrease the PM oxidation temperature significantly on a catalyzed DPF (CDPF). The oxidation characteristics of PM with hydrogen supplied to CDPF were studied using a partial flow system. The partial flow system was used to control temperature and a flow rate independently. The CDPF was coated with Pt/Al₂O₃ 25g/ft₃, and a multi-channel CDPF (MC CDPF) with a square cross section of 1.65 cm width and length of 10 cm was used.
2010-04-12
Technical Paper
2010-01-0563
Svetlana Iretskaya, Steve Golden, Ted Tadrous, Shun Hong Long
Non-PGM catalyst containing base metal mixed oxide (BMMO) supported on rare earth mixed oxide (REMO) had been evaluated by various methods for soot-oxidation activity. Thermo-gravimetric/Differential Thermal Analysis (TG/DTA) experiments and synthetic gas bench activity tests showed that the catalyst was able to oxidize soot at temperatures significantly lower than soot combustion temperature leading to a conclusion that soot was oxidized via direct reaction with active species of the catalyst surface. It had been shown that low-temperature soot oxidation occurred with and without NO present in the reaction gas. Evaluation on engine benches of the BMMO catalyst coated on diesel particulate filters (DPF) confirmed low-temperature soot oxidation in exhaust gas with low NO₂ concentration and a possibility of cost-efficient diesel exhaust aftertreatment system without increasing tailpipe NO₂ content.
2010-04-12
Journal Article
2010-01-0569
Hanlong Yang, Christian Chimner
Future government emission regulations have lead to the development and implementation of advanced aftertreatment systems to meet stringent emission standards for both on-road and off-road vehicles. These aftertreatment systems require sophisticated control and diagnostic strategies to ensure proper system functionality while minimizing tailpipe NOx and PM emissions across all engine operating conditions. In this paper, an integrated algorithm design approach with controls and diagnostics for an aftertreatment system consisting of a fuel doser, fuel reformer, LNT, DPF, and SCR is discussed.
2010-04-12
Technical Paper
2010-01-0539
Thomas Wolff, Holger Friedrich, Lars Tinggaard Johannesen, Shahrokh Hajireza
Diesel particulate filters (DPF) are now a mandatory part in diesel exhaust aftertreatment systems in order to achieve compliance with current emission legislations. However future demands for further NOx and CO₂ reductions combined with a maximum amount of allowed particle numbers per ccm lead to special requirements for the DPF substrate material. On the one hand high filtration efficiency of soot particles in the nanometer scale has to be reached and on the other hand high porosities and large pore sizes have to be realized to support catalytic coating. In order to have a base material composition which can easily be modified to meet current and future demands a new SiC substrate, called XP-SiC, was developed. The technology of the XP-SiC is based on a reaction forming process of coextruded silicon and carbon particles to SiC. This new manufacturing process leads to a unique microstructure with a sponge-like appearance and a high porosity in the range of 50% - 70%.
2010-04-12
Journal Article
2010-01-0538
Xiaogang Zhang, Paul Tennison, William Ruona
The main objective of this paper is to investigate the performance of partial filtration DPF substrates using 3-D Computational Fluid Dynamics (CFD) methods. Detailed 3-D CFD simulations were performed for real world sizes of DPF inlet and outlet channel geometries. Two concepts of partial filters were studied. The baseline geometry was a standard DPF with the front plugs removed. The second concept was to eliminate half of outlet plugs in addition to the inlet plugs to improve the pressure drop performance. The total filter efficiency was defined in current study to quantify the overall filter filtration efficiency which combines the effects from wall flow efficiency and flow through efficiency. For baseline case, 45% of total exhaust gas was found to go through the inlet channels, and the total trap efficiency was as high as 60%. However, only a 10% pressure loss reduction was found due to the removal of the outlet channel plugs from the DPF inlet side.
2010-04-12
Journal Article
2010-01-0590
John E. Kirwan, Mark Shost, Gregory Roth, James Zizelman
Today turbo-diesel powertrains offering low fuel consumption and good low-end torque comprise a significant fraction of the light-duty vehicle market in Europe. Global CO₂ regulation and customer fuel prices are expected to continue providing pressure for powertrain fuel efficiency. However, regulated emissions for NO and particulate matter have the potential to further expand the incremental cost of diesel powertrain applications. Vehicle segments with the most cost sensitivity like compacts under 1400 kg weight look for alternatives to meet the CO₂ challenge but maintain an attractive customer offering. In this paper the concepts of downsizing and downspeeding gasoline engines are explored while meeting performance needs through increased BMEP to maintain good driveability and vehicle launch dynamics. A critical enabler for the solution is adoption of gasoline direct injection (GDi) fuel systems.
2010-04-12
Technical Paper
2010-01-0498
Cristiana Delprete, Carlo Rosso, Andrea Vercelli
Thermo-structural analysis of components is usually carried out by means of two FE models, one that solves the thermal problem and one that, using the results of the thermal model, computes strains and stresses. The interaction between the two models is based on the superposition principle, but it means that the mutual effects and the non-linearities between the two physical problems are neglected. In this paper a multiphysics approach based on the Cell Method is proposed and it is applied to a time dependent thermo-mechanical case study represented by an exhaust manifold simulacrum: the coupled thermal and mechanical problems are solved in an unique run, giving the opportunity to take into account mutual effects. Comparing the results with the traditional FE analysis the advantages in terms of accuracy and computational time achieved through the proposed methodology are highlighted.
2011-04-12
Technical Paper
2011-01-0416
Sunghoon Lee, Bosung Shin
This paper describes Kappa dual CVVT (Continuously Variable Valve Timing) gasoline engine that Hyundai has developed for small cars lately. This engine is produced at engine plants in India and South Korea. This engine has been installed in small passenger cars named "i10," "i20," "Picanto," etc., and introduced into world market including Europe and India. Nowadays, car makers in the world have been competitively developing small cars in order to cope with rising oil price and becoming more stringent CO₂ emission regulations. The new engine has been introduced into market since November 2010. Main development goals of this engine were to reduce CO₂ emission and improve fuel economy. As a small engine, it was also developed in consideration of generous engine torque, lighter weight, minimal noise, lower cost and compact size. This paper presents various technologies featuring higher torque, better fuel efficiency, lower noise level and lighter weight.
2011-04-12
Technical Paper
2011-01-0419
Masayuki Shimizu, Kazunori Yageta, Yoshinori Matsui, Takahiro Yoshida
This paper describes a new 1.6-liter four-cylinder gasoline turbocharged engine with a direct injection gasoline (DIG) system and a twin continuously variable valve timing control (CVTC) system. Demands for higher environmental performance make it necessary to improve engine efficiency further. At the same time, improvement of power performance is important to enhance the appeal of vehicles and make them attractive to consumers. In order to meet these requirements, a 1.6-liter direct injection gasoline turbocharged engine has been developed. By using many friction reduction technologys, this engine achieves the high power performance of a 2.5-liter NA(Naturally Aspirated) gasoline engine and low fuel consumption comparable to that of a smaller displacement engine. In addition, this engine achieves low exhaust emission performance to comply with the US LEV2-ULEV and EU Euro5 emission requirements.
2011-04-12
Technical Paper
2011-01-0658
Juan Carlos Martinez Laurent
With the constant need to meet new environmental regulations, the improvement of automotive exhaust systems technologies to be cleaner and more effective is a necessity. To achieve these regulations the automakers have been focused on the development of better particle filters and more effective cleaning processes. Catalyst Oxidation and Diesel Particle Filter Regeneration are good and effective techniques to accomplish these objectives but the amount of heat generated by these processes is a concern in the thermal management of the vehicle. To gain a better understanding of these effects Finite Element Thermal Analysis has proved to be a useful tool to predict and observe the increment of temperature during these processes. This work is focus on a simulation process using several 1-D and 3-D techniques to predict the skin exhaust temperature during the regeneration process moment in which the system achieve the maximum temperature.
2010-04-12
Technical Paper
2010-01-1299
Barouch Giechaskiel, Massimo Carriero, Giorgio Martini, Alexander Bergmann, Helmut Pongratz, Herwig Joergl
The regulation of particle number (PN) has been introduced in the Euro 5/6 light-duty vehicle legislation, as a result of the light duty inter-laboratory exercise of the Particle Measurement Program (PMP). The heavy-duty inter-laboratory exercise investigates whether the same or a similar procedure can be applied to the heavy-duty regulation. In the heavy-duty exercise two "golden" PN systems sample simultaneously; the first from the full dilution tunnel and the second from the partial flow system. One of the targets of the exercise is to compare the PN results from the two systems. In this study we follow a different approach: We use a PMP compliant system at different positions (full flow, partial flow and tailpipe) and we compare its emissions with a "reference" system always sampling from the full flow dilution tunnel.
2010-04-12
Technical Paper
2010-01-1119
Francisco Payri, Jose Lujan, Hector Climent, Benjamín Pla
Despite the development in NOx aftertreatment for Diesel engines, EGR is a cost-effective solution to fulfill current and future emission regulations. There is a wide bibliography discussing the global effects of EGR on combustion and emissions. However, little has been published concerning the effects of the unsuitable EGR and air distribution among cylinders. Since current HSDI engines operate with EGR rates as high as 50% the effect of the unequal EGR distribution becomes important. In addition, cylinder-to-cylinder charge dispersion becomes a critical aspect on the control of low temperature combustion systems. In concordance with the aspects outlined before, the aim of this paper is to study the effects of the EGR cylinder to cylinder distribution on the engine performance and emissions. To cope with this objective, experiments have been conducted in a HSDI engine with two different EGR systems.
2010-05-05
Technical Paper
2010-01-1575
D. S. Deshmukh, J. P. Modak, K. M. Nayak
This paper concentrates on backpressure phenomenon, which is a subject of specific interest for design and operation of energy efficient exhaust system development in case of C.I. engine applications. To minimize the problem of back pressure rise, quick and economically feasible solutions are briefly discussed here. Considering the complete system objectives for efficient C.I. engine system development requires minimum fuel consumption and maximum utilization of input energy for reduction of the exhaust emissions and also for effective waste energy recovery system from each subsystem. Specifically particulate matter emission control requires diesel particulate filter, this is a major cause of rise in backpressure.
2010-05-05
Journal Article
2010-01-1555
Guillaume Latouchent, PIerre Darcy, Bertrand Coulet
This study deals with a coupled experimental and modeling approach of Diesel Particulate Filter cracking. A coupled model (heat transfer, mass transfer, chemical reactions) is used to predict the temperature field inside the filter during the regeneration steps. This model consists of assembled 1D models and is calibrated using a set of laboratory bench tests. In this set of experiments, laboratory scale filters are tested in different conditions (variation of the oxygen rate and gas flow) and axial/radial thermal gradient are recorded with the use of thermocouples. This model is used to build a second set of laboratory bench tests, which is dedicated to the understanding of the phenomena of Diesel Particulate Filter cracking.
2010-05-05
Technical Paper
2010-01-1569
Shunxin Zhou
Study and design of the lifetime durability of mechanical components in an automotive exhaust system becomes a challenging task today for engineers. During the investigation, both experimental tests and finite element simulations are used for the investigation under dynamic engine excitations. For the dynamic finite element analysis, the experimental system must be simplified as a linear mathematic model and real boundary conditions are idealized. Due to this simplification, the dynamic behavior of the finite element model may strongly deviate from that in operational conditions. To gain insight into the dynamic behavior of exhaust systems from simulations, the finite model must be modified based on experimental results. As known the harmonic response is related to modal shapes and engine loads. Therefore, modifications of the finite element model can be done from these two aspects.
2010-06-09
Technical Paper
2010-01-1427
Mansinh S. Kumbhar, Atul Miskin, Vishal Chaudhari
Increase in customer's awareness for better vehicle NVH has prompted automobile industry to address NVH issues more seriously. Among other critical vehicle systems for NVH, Air Intake and Exhaust Systems play an important role in terms of passenger compartment noise, sound quality and vehicle pass-by noise. Hence proper design & development of these systems is imperative to reduce their contribution in overall vehicle NVH. This needs to be achieved within constraints of meeting other functional requirements such as emissions and engine performance. The design parameters one needs to look at while developing the intake and exhaust system are mainly the acoustic transmission loss, structural noise radiations from the surfaces and structural isolation between body and these systems. This paper demonstrates the use of FEM approach for Vibro-Acoustic Analysis as a practical means for design of intake and exhaust system in terms of high transmission loss.
2010-04-12
Technical Paper
2010-01-0537
Kyeong O. Lee, Seung Yeon Yang
The limited spatial area in conventional diesel particulate filter (DPF) systems requires frequent regenerations to remove collected particulate matter (PM) emissions, consequently resulting in higher energy consumption and potential material failure. Due to the complex geometry and difficulty in access to the internal structure of diesel particulate filters, in addition, many important characteristics in filtration processes remain unknown. In this work, therefore, the geometry of DPF membrane channels was modified basically to increase the filtration areas, and their filtration characteristics were evaluated in terms of pressure drop across the DPF membranes, effects of soot loading on pressure drop, and qualitative soot mass distribution in the membrane channels. In this evaluation, an analytical model was developed for pressure drop, which allowed a parametric study with those modified membranes.
2010-04-12
Journal Article
2010-01-0536
Raphaël Berthelin, Patrick Girot
On September 1 st 2011, the Euro 5 + emission legislation will apply to passenger cars in Europe. It is characterized by the introduction of a new regulation concerning the number of soot particle emissions, whereas Euro5 legislation only applies to soot mass. This new regulation makes it necessary to investigate the impact of filter design on filtration efficiency as it pertains to particle number and to the Diesel Particulate Filter (DPF) operating window. This paper describes the investigation performed on a light duty test bench equipped with a Differential Mobility Spectrometer (DMS) which measures soot concentration number and soot particle size distribution in the exhaust gas effluent. Specific protocols were developed to be able to evaluate filtration efficiency in particle number when the DPF is empty of soot and also when the filter is soot loaded. Several DPF parameters such as filter length, filter diameter, cell geometry, and microstructure were studied.
2010-04-12
Technical Paper
2010-01-0534
Shohji Tsushima, Issei Nakamura, Satoshi Sakashita, Shuichiro Hirai, Daisuke Kitayama
In this study, particle transport and captured behaviors in a Diesel Particulate Filter (DPF) was investigated with Lattice Boltzmann Method. LBM calculation was performed to a 3D-reconstructed micro porous DPF substrate, which was obtained by micro-focus 3D X-ray technique. Simulating advection-diffusion behaviors of diesel particulates in micro porous channel, we adapted a LBM method used for high Peclet number flow, simulating flow conditions in DPFs. We investigated flow behaviors in a wide variety of inlet velocity. LBM simulation has clearly shown that non-dimensional flow field is similar in wide range of flow conditions in the DPF, because flow Reynolds number in the micro porous substrate is sufficiently low, dominated by laminar flow regime. It was also revealed that less than 40% pore channels was responsible for more than 80% volume flux in the porous substrate without particle loading.
2010-04-12
Journal Article
2010-01-0533
James R. Warner, Douglas Dobson, Giovanni Cavataio
In this study an attempt to understand and demonstrate the effects of various washcoat technologies under active and passive regeneration conditions was performed. Six different formulations, on 1.0" D. x 3.0" L. SiC wall flow filters at the laboratory level were used at various test conditions, including variable NO₂/NO ratios and O₂ concentrations. Samples were regenerated using active and passive conditions to evaluate regeneration rates and the potential impact of regeneration at the vehicle level. Results were applied to vehicle operating conditions to determine passive functionality and potential benefits. Active regenerations at 2% O₂ and 5% O₂ showed no significant difference in time to complete regeneration and soot burn rates. Active regenerations performed at 1% O₂ and 5% O₂ concentration showed that the regeneration temperature was shifted by approximately 50°C.
2010-04-12
Technical Paper
2010-01-0532
Hans-Joerg Rembor, Thomas Rahn
In this paper, a new diesel particle filter material made from silicon carbide sintered in a liquid phase is presented. The sintering process allows for controlling of certain parameters that influence the extrusion process, the material properties and hence the filtering characteristics. Furthermore, using triangular channel geometry to build up a wall flow filter makes it possible to have a newly segmented geometry that leads to hexagonal shaped filter cartridges. A variety of on the market available wall flow filter materials are compared with data about material porosity, particle size distribution, strength, specific filtration surface as well other parameters influencing the filtration efficiency. The material characteristics gathered are analyzed and evaluated.
2010-04-12
Technical Paper
2010-01-0531
Takashi Mizutani, Shingo Iwasaki, Yukio Miyairi, Kazuya Yuuki, Mikio Makino, Hiroshi Kurachi
The Inlet-Membrane DPF which has a small pore size membrane formed on the inlet side of the body wall has been developed as a next generation diesel particulate filter (DPF). It simultaneously realizes low pressure drop, small pressure drop hysteresis, high robustness and high filtration efficiency. The low pressure drop improves fuel economy. The small pressure drop hysteresis has the potential to extend the regeneration interval since the linear relationship between the pressure drop and accumulated soot mass improves the accuracy of the soot mass detection by means of the pressure drop values. The Inlet-Membrane DPF's high robustness also extends the regeneration interval resulting in improved fuel economy and a lower risk of oil dilution while its high filtration efficiency reduces PM emissions. The concept of the Inlet-Membrane DPF was confirmed using disc type filters in 2008 and its performances was evaluated using full block samples in 2009.
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