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2016-04-05
Technical Paper
2016-01-0912
MohanKumar Subramaniam, Senthilkumar Pachamuthu, Jayanth Arulanandan, Jenoris Muthiya
Abstract Exhaust after treatment devices in diesel engines play a crucial role in control of harmful emissions. The noxious emission released from diesel engines causes a variety of problems to both human beings and the environment. The currently used devices are implemented with new catalyst technologies like DOC, SCR and catalytic converter are all designed to meet stringent emission regulations. Although these devices have considerable conversion efficiency, they are not without drawbacks. The catalysts used in these devices are rarely available and are also very expensive. Diesel Particulate Filter (DPF) is the device currently employed to collect particulate matter. It also has drawbacks like high back pressure, thermal durability restrictions, regeneration issues and poor collection of smaller size particles. In the case of biodiesel these fine sized particles are emitted in larger quantity.
2016-04-05
Technical Paper
2016-01-0916
Nebojsa Milovanovic, Shant Hamalian
Abstract The future emission legislations for diesel passenger cars are likely to include more dynamic test cycles than we have today, such as the World harmonized Light duty Testing Cycle (WLTC) and Real Drive Emissions (RDE) in the EU and very challenging SULEV legislations in the USA. In order to meet these emission legislations and challenging CO2 targets, more complex Exhaust Gas After Treatment Systems - EGATS and corresponding calibration strategies are needed. The calibration strategies have to provide the best possible fuel consumption and NOx emissions across the entire engine map for all tested cycles. The aim of this paper is to evaluate the effect of several EGATS configurations and calibrations on tailpipe NOx and CO2 emissions of a D segment vehicle. The experimental results and potential of various EGATS configurations and calibrations for the optimisation of fuel consumption and NOx emissions are presented and discussed.
2016-04-05
Technical Paper
2016-01-0918
Alexander Sappok, Paul Ragaller, Leslie Bromberg, Vitaly Prikhodko, John Storey, James Parks
Abstract Radio frequency (RF)-based sensors provide a direct measure of the particulate filter loading state. In contrast to particulate matter (PM) sensors, which monitor the concentration of PM in the exhaust gas stream for on-board diagnostics purposes, RF sensors have historically been applied to monitor and control the particulate filter regeneration process. This work developed an RF-based particulate filter control system utilizing both conventional and fast response RF sensors, and evaluated the feasibility of applying fast-response RF sensors to provide a real-time measurement of engine-out PM emissions. Testing with a light-duty diesel engine equipped with fast response RF sensors investigated the potential to utilize the particulate filter itself as an engine-out soot sensor.
2016-04-05
Technical Paper
2016-01-0920
Bradford A. Bruno, Ann M. Anderson, Mary Carroll, Thomas Swanton, Paul Brockmann, Timothy Palace, Isaac A. Ramphal
Abstract Aerogels are nanoporous structures with physical characteristics that make them promising for use in automotive exhaust catalysis systems: highly porous with low densities (<0.1 g/mL) and high surface area per unit mass (>300 m2/g) - features that provide favorable characteristics for catalysis of gaseous pollutants. Ceramic aerogels are also highly thermally insulating (∼0.015 W/mK) and able to withstand high temperatures. Aerogels can be made of a wide variety of ceramics (e.g. alumina, silica, titania) with other catalytically active metals (e.g. copper, cobalt, nickel) incorporated into their structures. This paper provides a brief overview of the rapid supercritical extraction (RSCE) method employed in this work for aerogel preparation, describes in detail the benchtop scale testbed and methods used to assess the catalytic activity of RSCE fabricated aerogels, and presents data on the catalytic ability of some promising aerogel chemistries.
2016-04-05
Technical Paper
2016-01-0923
Martin Schneider, Bernd Danckert
Abstract Since the new “Regulations for the Prevention of Air Pollution from Ships” of the International Maritime Organization (IMO; MARPOL Annex VI Tier III) became effective, new technologies in marine applications are needed to fulfill the exhaust-gas limits. The reduction rate of the permissible emissions in the emission control areas (ECA) is about 75 % from Tier II to Tier III. To meet these limits, it is necessary to take additional measures, such as installing a Selective Catalytic Reduction (SCR) system. Because harbors are specifically in focus regarding the air quality, a hybrid propulsion system (Diesel-electric) and Exhaust Aftertreatment (EAT) to reduce the emissions and the lifecycle costs by reducing the fuel consumption were planned back in 2012. With the goal in mind of decreasing all relevant emissions, the described compact EAT consists of a Diesel Oxidation Catalyst (DOC), a Particulate Matter (PM) removal and a SCR-catalyst.
2016-04-05
Technical Paper
2016-01-0924
Shun Nakagawa, Ichiro Tsumagari, Shinya Sato, Koichi Machida
Abstract The conventional NOx after-treatment system could not perform sufficient NOx removal since exhaust gas temperature falls down by low-fuel-consumption and waste heat recovery of a diesel engine. In order to realize a new after-treatment system with high NOx conversion rate at a low catalyst temperature, studies on adopting an ozone generator (NO oxidization promotion) and a urea reformer (ammonia addition) into the Urea SCR (Selective Catalytic Reduction) system have been conducted.
2016-04-05
Technical Paper
2016-01-0892
Oliver P. Taylor, Richard Pearson, Richard Stone
Abstract Most major regional automotive markets have stringent legislative targets for vehicle greenhouse gas emissions or fuel economy enforced by fiscal penalties. Large improvements in vehicle efficiency on mandated test cycles have already taken place in some markets through the widespread adoption of technologies such as downsizing or dieselisation. There is now increased focus on approaches which give smaller, but significant incremental efficiency benefits, such as reducing parasitic losses due to engine friction. The reduction in tail pipe CO2 emissions through the reduction of engine friction using lubricants has been reported by many authors. However, opportunities also exist to reduce the lubricant viscosity during warm up by the thermal management of the lubricant mass.
2016-04-05
Technical Paper
2016-01-0194
Yici Li, Wei Tian
Abstract The exhaust cooling is an important index which measures the performance of the flameproof diesel engine. In this paper, a modification model is built for enhancing the cooling performance of exhaust, based on the reference model of the dry cooling equipment. The annular nozzle direction, extend plate of guide, bellows and elbow are introduced and studied in the model as the modification way. Considering the Coanda and Venturi effects, the comprehensive comparison of fluid velocity, temperature, pressure and mixture coefficient is implemented, and the optimum horizontal dimension of throat is summarized. The simulation results indicate the modification model shows better performance in reducing exhaust temperature and pressure than the reference model.
2016-04-05
Technical Paper
2016-01-0571
Guillaume Bernard, Mark Scaife, Amit Bhave, David Ooi, Julian Dizy
Abstract Internal combustion (IC) engines that meet Tier 4 Final emissions standards comprise of multiple engine operation and control parameters that are essential to achieve the low levels of NOx and soot emissions. Given the numerous degrees of freedom and the tight cost/time constraints related to the test bench, application of virtual engineering to IC engine development and emissions reduction programmes is increasingly gaining interest. In particular, system level simulations that account for multiple cycle simulations, incylinder turbulence, and chemical kinetics enable the analysis of combustion characteristics and emissions, i.e. beyond the conventional scope of focusing on engine performance only. Such a physico-chemical model can then be used to develop Electronic Control Unit in order to optimise the powertrain control strategy and/or the engine design parameters.
2016-04-05
Technical Paper
2016-01-0565
SoDuk Lee, Charles Schenk, Joseph McDonald
Abstract As part of the U.S. Environmental Protection Agency (U.S. EPA) “Midterm Evaluation of Light-duty Vehicle Standards for Model Years 2022-2025 [1]”, the U.S. EPA is evaluating engines and assessing the effectiveness of future engine technologies for reducing CO2 emissions. Such assessments often require significant development time and resources in order to optimize intake and exhaust cam variable valve timing (VVT), exhaust gas recirculation (EGR) flow rates, and compression ratio (CR) changes. Mazda SkyActiv-G spark-ignition (SI) engines were selected by EPA for an internal engine development program based upon their high geometric compression ratio (14:1 in Europe and Japan, 13:1 in North America) and their use of a flexible valve train configuration with electro-mechanical phasing control on the intake camshaft.
2016-04-05
Technical Paper
2016-01-0580
Joohan Kim, Namho Kim, Kyoungdoug Min
Abstract The soot emission in direct-injection spark-ignition engines under various operating conditions was numerically investigated in the present study. A detailed soot model was used to resolve the physical soot process that consists of polycyclic aromatics hydrocarbon (PAH) formation and soot particle dynamics. The primary propagating flame in partially-premixed field was described by G-equation model, and the concentrations of burned species as well as PAH behind of the flame front were determined from the laminar flamelet library that incorporates the PAH chemical mechanism. The particle dynamics in post-flame region include nucleation, surface growth, coagulation, and oxidation were modeled by method of moments. To improve the model predictability, a gasoline surrogate model was proposed to match the real fuel properties, and the input of droplet size distribution of fuel spray was obtained from Phase-Doppler Particle Analyzer.
2016-04-05
Technical Paper
2016-01-0575
Konstantinos Siokos, Rohit Koli, Robert Prucka, Jason Schwanke, Shyam Jade
Abstract Low pressure (LP) and cooled EGR systems are capable of increasing fuel efficiency of turbocharged gasoline engines, however they introduce control challenges. Accurate exhaust pressure modeling is of particular importance for real-time feedforward control of these EGR systems since they operate under low pressure differentials. To provide a solution that does not depend on physical sensors in the exhaust and also does not require extensive calibration, a coupled temperature and pressure physics-based model is proposed. The exhaust pipe is split into two different lumped sections based on flow conditions in order to calculate turbine-outlet pressure, which is the driving force for LP-EGR. The temperature model uses the turbine-outlet temperature as an input, which is known through existing engine control models, to determine heat transfer losses through the exhaust.
2016-04-05
Technical Paper
2016-01-0576
Chad Koci, Kenth Svensson, Christopher Gehrke
Abstract A two-zone NOx model intended for 1-D engine simulations was developed and used to model NOx emissions from a 2.5 L single-cylinder engine. The intent of the present work is to understand key aspects of a simple NOx model that are needed for predictive accuracy, including NOx formation and destruction phenomena in a DI Diesel combustion system. The presented two-zone model is fundamentally based on the heat release rate and thermodynamic incylinder data, and uses the Extended Zeldovich mechanism to model NO. Results show that the model responded very well to changes in speed, load, injection timing, and EGR level. It matched measured tail pipe NOx levels within 20%, using a single tuning setup. When the model was applied to varied injection rate shapes, it showed correct sensitivity to speed, load, injection timing, and EGR level, but the absolute level was well outside the target accuracy. The same limitation was seen when applying the Plee NOx model.
2016-04-05
Technical Paper
2016-01-0590
Alexandros Hatzipanagiotou, Paul Wenzel, Christian Krueger, Raul Payri, Jose M. Garcia-Oliver, Walter Vera-Tudela, Thomas Koch
Abstract In this work a detailed soot model based on stationary flamelets is used to simulate soot emissions of a reactive Diesel spray. In order to represent soot formation and oxidation processes properly, a calibration of the soot reaction rates has to be performed. This model calibration is usually performed on basis of engine out soot measurements. Contrary to this, in this work the soot model is calibrated on local soot concentrations along the spray axis obtained from laser extinction chamber measurements. The measurements are performed with B7 certification Diesel and a series production multihole injector to obtain engine similar boundary conditions. In order to ensure that the flow and mixture field is captured well by the CFD-simulation, the simulated liquid penetration lengths and flame lift-off lengths are compared to chamber measurements.
2016-04-05
Technical Paper
2016-01-0548
Estefanía Hervas-Blasco, Emilio Navarro-Peris, José Corberan, Alex Rinaldi
Abstract Nowadays, more than 50% of the fuel energy is lost in CNG Engines. While efforts to increase their efficiency have been focused mainly on the improvement of the combustion process, the combustion chamber and the reduction of friction losses, heat losses still remain the most important inefficient factor. A global strategy in which several energy recovery strategies are implemented could lead to engine improvements up to 15%. Therefore, the development of accurate models to size and predict the performance of the integrated components as well as to define an optimized control strategy is crucial. In this contribution, a model to analyze the potential of a new powertrain based on the electrification of the main auxiliaries, the integration of a kinetic energy recovery system and the exhaust gases heat recovery through a thermoelectric generator and a turbo-component is presented.
2016-04-05
Technical Paper
2016-01-0550
Zhijia Yang, Edward Winward, Gary O'Brien, Richard Stobart, Dezong Zhao
Abstract The intrinsic model accuracy limit of a commonly used Exhaust Gas Recirculation (EGR) mass flow rate model in diesel engine air path control is discussed in this paper. This EGR mass flow rate model is based on the flow of a compressible ideal gas with unchanged specific heat ratio through a restriction cross-area within a duct. A practical identification procedure of the model parameters is proposed based on the analysis of the engine data and model structure. This procedure has several advantages which include simplicity, low computation burden and low engine test cost. It is shown that model tuning requires only an EGR valve sweep test at a few engine steady state operating points.
2016-04-05
Technical Paper
2016-01-0562
Hassan Karaky, Gilles Mauviot, Xavier Tauzia, Alain Maiboom
Abstract Due to its harmful effect on both human health and environment, soot emission is considered as one of the most important diesel engine pollutants. In the last decades, the industrial engine manufacturers have been able to strongly reduce its engine-out value by many different techniques, in order to respect the stricter emission norms. Simulation modeling has played and continues to play a key role for this purpose in the engine control system development. In this context, this paper proposes a new soot emission model for a direct injection diesel engine. This soot model is based on a zero-dimensional semi-physical approach coupled with a crank-angle resolved combustion model and a thermodynamic calculation of the burned gas products temperature. Furthermore, a multi linear regression model has been used to estimate the soot emissions as function of significant physical combustion parameters.
2016-04-05
Technical Paper
2016-01-0561
Seungha Lee, Youngbok Lee, Kyoungchan Han, Kyoung Min Lee, Jun Yu, Junyong Lee, Kyoungdoug Min
Abstract Currently, diesel engine-out exhaust NOx emission level prediction is a major challenge for complying with the stricter emission legislation and for control purpose of the after-treatment system. Most of the NOx prediction research is based on the Zeldovich thermal mechanism, which is reasonable from the physical point of view and for its simplicity. Nevertheless, there are some predictable range limitations, such as low temperature with high EGR rate operating conditions or high temperature with low EGR rates. In the present paper, 3 additional considerations, pilot burned gas mixing before the main injection; major NO formation area; concentration correction, were applied to the previously developed real-time NO estimation model based on in-cylinder pressure and data available from ECU. The model improvement was verified on a 1.6 liter EURO5 diesel engine in both steady and transient operation.
2016-04-05
Technical Paper
2016-01-0558
Christoph Poetsch, Tomaz Katrasnik
Abstract The present work introduces an innovative mechanistically based 0D spray model which is coupled to a combustion model on the basis of an advanced mixture controlled combustion approach. The model calculates the rate of heat release based on the injection rate profile and the in-cylinder state. The air/fuel distribution in the spray is predicted based on momentum conservation by applying first principles. On the basis of the 2-zone cylinder framework, NOx emissions are calculated by the Zeldovich mechanism. The combustion and emission models are calibrated and validated with a series of dedicated test bed data specifically revealing its capability of describing the impact of variations of EGR, injection timing, and injection pressure. A model based optimization is carried out, aiming at an optimum trade-off between fuel consumption and engine-out emissions. The findings serve to estimate an economic optimum point in the NOx/BSFC trade-off.
2016-04-05
Technical Paper
2016-01-0606
Chaitanya Wadkar, Bassem H. Ramadan
Abstract A numerical and experimental study of the use of air motion control, piston bowl shape, and injector configuration on combustion and emissions in diesel engines has been conducted. The objective of this study is to investigate the use of flow control within the piston bowl during compression to enhance fuel air mixing to achieve a uniform air-fuel mixture to reduce soot and NO emissions. In addition to flow control different piston bowl geometries and injector spray angles have been considered and simulated using three-dimensional computational fluid dynamics and experiments. The results include cylinder pressure and emissions measurements and contour plots of fuel mass fraction, soot, and NO. The results show that soot and NO emissions can be reduced by proper flow control and piston bowl design.
2016-04-05
Technical Paper
2016-01-0611
Dejan Kihas, Daniel Pachner, Lubomir Baramov, Michael Uchanski, Priya Naik, Nassim Khaled
Abstract The interest for NOx estimators (also known as virtual sensors or inferential sensors) has increased over the recent years due to benefits attributed to cost and performance. NOx estimators are typically installed to improve On-Board Diagnostics (OBD) monitors or to lower bill of material costs by replacing physical NOx sensors. This paper presents initial development results of a virtual engine-out NOx estimator planned for the implementation on an ECM. The presented estimator consists of an airpath observer and a NOx combustion model. The role of the airpath observer is to provide input values for the NOx combustion model such as the states of the gas at the intake and exhaust manifolds. It contains a nonlinear mean-value model of the airpath suitably transformed for an efficient and robust implementation on an ECM. The airpath model uses available sensory information in the vehicle to correct predictions of the gas states.
2016-04-05
Technical Paper
2016-01-0612
Rohit Koli, Konstantinos Siokos, Robert Prucka, Shyam Jade, Jason Schwanke
Abstract Low-pressure cooled EGR (LP-cEGR) systems can provide significant improvements in spark-ignition engine efficiency and knock resistance. However, open-loop control of these systems is challenging due to low pressure differentials and the presence of pulsating flow at the EGR valve. This research describes a control structure for Low-pressure cooled EGR systems using closed loop feedback control along with internal model control. A Smith Predictor based PID controller is utilized in combination with an intake oxygen sensor for feedback control of EGR fraction. Gas transport delays are considered as dead-time delays and a Smith Predictor is one of the conventional methods to address stability concerns of such systems. However, this approach requires a plant model of the air-path from the EGR valve to the sensor.
2016-04-05
Technical Paper
2016-01-0616
Jayant Sarlashkar, Sankar Rengarajan, Ryan Roecker
Abstract Southwest Research Institute (SwRI) has successfully demonstrated the cooled EGR concept via the High Efficiency Dilute Gasoline Engine (HEDGE) consortium. Dilution of intake charge provides three significant benefits - (1) Better Cycle Efficiency (2) Knock Resistance and (3) Lower NOx/PM Emissions. But EGR dilution also poses challenges in terms of combustion stability, condensation and power density. The Dedicated EGR (D-EGR) concept brings back some of the stability lost due to EGR dilution by introducing reformates such as CO and H2 into the intake charge. Control of air, EGR, fuel, and ignition remains a challenge to realizing the aforementioned benefits without sacrificing performance and drivability. This paper addresses the DEGR solution from a controls standpoint. SwRI has been developing a unified framework for controlling a generic combustion engine (gasoline, diesel, dual-fuel natural gas etc.).
2016-04-05
Technical Paper
2016-01-0618
Feilong Liu, Jeffrey M. Pfeiffer, Ron Caudle, Peter Marshall, Peter Olin
Abstract Low Pressure Cooled Exhaust Gas Recirculation (LP EGR) is an attractive technology to reduce fuel consumption for a spark-ignition (SI) engine, particularly at medium-to-high load conditions, due to its knock suppression and combustion cooling effects. However, the long LP EGR transport path presents a significant challenge to the transient control of LP EGR for the engine management system. With a turbocharged engine, this is especially challenging due to the much longer intake induction system path compared with a naturally aspirated engine. Characterizing and modeling the EGR, intake air mixing and transport delay behavior is important for proper control. The model of the intake air path includes the compressor, intercooler and intake plenum. It is important to estimate and track the final EGR concentration at the intake plenum location, as it plays a key role in combustion control.
2016-04-05
Technical Paper
2016-01-0409
Fatih Unal, Cem Sorusbay
Abstract In an effort to support design and testing activities at product development lifecycle of the engine, proper duty cycle is required. However, to collect data and develop accurate duty cycles, there are not any vehicles equipped with prototype engines at customers. Therefore, in this paper, discrete duty cycle development methodology is studied to generate trailer truck engine usage profile which represents driving conditions in Turkey for engines in development phase. Cycles are generated using several vehicles equipped with prototype engines and professional drivers that can mimic customer usage. Methodology is based on defining real-world customer driving profile, discretizing real-world drives into separate events, collecting vehicle data from each discrete drive, determining the weight of events by conducting customer surveys and creating a representative reference usage profile with data analysis.
2016-04-05
Technical Paper
2016-01-1070
Gopichandra Surnilla, Richard Soltis, James Hilditch, Christopher House, Timothy Clark, Matthew Gerhart
Abstract Traditional EGR measurement systems using delta pressure over a fixed orifice such as a DPFE sensor (Delta Pressure Feedback for EGR), have limitations in the ability to measure EGR accurately. Also, the pressure drop that results from the orifice may not be acceptable in some applications. To measure the EGR accurately and without any pressure loss, a new measurement system was developed that uses an oxygen sensor in the intake air. In this paper, the technology of using an oxygen sensor to measure the EGR concentration is discussed. The paper details the EGR measurement principle with an oxygen sensor and the associated mathematical relations of translating the oxygen measurement to EGR measurement. Factors affecting the EGR measurement such as the air/fuel ratio of the EGR, intake air pressure, and diffusion effects of the EGR constituents are discussed in detail. Compensation mechanisms are explained and associated results shown.
2016-04-05
Technical Paper
2016-01-1268
Yanjun Ren, Bo Yang, Gangfeng Tan, Xin Gao, Shichen Lu, Mengzuo Han, Ruobing Zhan, Haobo Xu
Abstract With the help of organic working medium absorbing the solar energy for steam electric power generation, green energy can be provided to automotive accessories so as to improve the vehicle energy efficiency. In the hot summer, the exhausted heat resulting from cars’ directly exposing to the sun can be used to cool and ventilate the passenger compartment. Considering the space occupied by the system in the combination of both practical features for solar heat source--low power and poor stability-- a compact evaporation structure was designed to enhance the solar utilization efficiency. In the research, the heat source of power and temperature variation range was determined by the available solar roof with photo-thermal conversion model. Then started from the ratio of exhausted heat utilization corresponding to evaporator’s characteristic parameter, the performance analysis was made in the different working conditions.
2016-04-05
Technical Paper
2016-01-1269
Naveen Kumar, Harveer Singh Pali
Abstract The present study was carried to explore the potential suitability of biodiesel as an extender of Kerosene in an off road dual fuel (gasoline start, kerosene run) generator set and results were compared with kerosene base line data. The biodiesel was blended with kerosene in two different proportions; 2.5% and 5% by volume. Physico-chemical properties of blends were also found to be comparable with kerosene. Engine tests were performed on three test fuels namely K100 (Kerosene 100%), KB 2.5 (Kerosene 97.5% + Biodiesel 2.5%) and KB5 (Kerosene 95% + Biodiesel 5%). It was found that brake thermal efficiency [BTE] increases up to 3.9% while brake specific energy consumption [BSEC] decreases up to 2.2% with increasing 5% volume fraction of biodiesel in kerosene. The exhaust temperature for blends was lower than kerosene. The test engine emitted reduced Carbon monoxide [CO] emission was 7.4 % less than using neat kerosene as compared to kerosene-biodiesel blends.
2016-04-05
Technical Paper
2016-01-1271
Shubhangi S. Nigade, S. Mutalikdesai
Abstract The fossil fuels are depleting rapidly and the prices are going up day by day. The vegetable oils converted into biodiesel have the potential of alternative fuels. There are several types of vegetable oils, edible & non-edible, which can be used for biodiesel production. Very little published work has been found on utilization of Madhuca Indica oil for biodiesel production including optimization of transesterification process. Very little research has been done on utilization of oil in general and optimization of transesterification process for biodiesel production using acid, base and heterogeneous (micro & nano) catalyst. In the present study, transesterification process with use of homogeneous and heterogeneous catalyst has been optimized.
2016-04-05
Technical Paper
2016-01-1275
Ganesh Duraisamy, Nagarajan Govindan, P. Shanmugam
Biodiesel obtained by transesterification process from the fatty leather waste (tannery waste water) was blended with Diesel in various proportions and it was tested in a single cylinder, naturally aspirated, direct injection (DI) Diesel engine of rated power 4.4 kW at the rated speed of 1500 rpm. Experiments were conducted with B10, B20, B30, B40 and B50 blends and their combustion, performance and emission characteristics were studied in comparison with conventional Diesel fuel. The experimental results show an increase in brake thermal efficiency with biodiesel blends compared to neat Diesel operation. Reduced ignition delay and combustion duration is observed for B30 blend compared to Diesel. The oxides of nitrogen emissions are significantly lower for B10 and B20 blends compared to Diesel operation, whereas with remaining blends the NOx emissions are increased compared to Diesel fuel.
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