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Viewing 31 to 60 of 24142
2016-11-08
Journal Article
2016-32-0028
Pascal Piecha, Philipp Bruckner, Stephan Schmidt, Roland Kirchberger, Florian Schumann, Stephan Meyer, Tim Gegg, Stefan Leiber
Abstract Small displacement two-stroke engines are widely used as affordable and low-maintenance propulsion systems for motorcycles, scooters, hand-held power tools and others. In recent years, considerable progress regarding emission reduction has been reached. Nevertheless, a further improvement of two-stroke engines is necessary to cover protection of health and environment. In addition, the shortage of fossil fuel resources and the anthropogenic climate change call for a sensual use of natural resources and therefore, the fuel consumption and engine efficiency needs to be improved. With the application of suitable analyses methods it is possible to find improving potential of the working processes of these engines. The thermodynamic loss analysis is a frequently applied method to examine the working process and is universally adaptable.
2016-11-08
Journal Article
2016-32-0065
Yoshinori Nakao, Yota Sakurai, Atsushi Hisano, Masahito Saitou, Masahide Kazari, Takahito Murase, Kozo Suzuki
In port injection, it is difficult to control in-cylinder fuel supply of each cycle in a transient state as cold start (in this paper, cold start is defined as several cycles from cranking at low engine temperature). Hence, THC, which is one of regulated emission gases, is likely to increase at cold start. As one of THC emission reduction approaches at cold start, the optimization of fuel injection specifications (including injection position and spray diameter) is expected to reduce THC emission. Setting injection position as downstream position is expected to secure the in-cylinder fuel supply amount at cold start because of small fuel adhesion amount on an intake port wall and a short distance between the injection position and in-cylinder. The position injection contributes to reduction of THC emission due to elimination of misfire.
2016-11-08
Journal Article
2016-32-0067
Akira Miyamoto, Kenji Inaba, Yukie Ishizawa, Manami Sato, Rei Komuro, Masashi Sato, Ryo Sato, Patrick Bonnaud, Ryuji Miura, Ai Suzuki, Naoto Miyamoto, Nozomu Hatakeyama, Masanori Hariyama
Abstract On the basis of extensive experimental works about heterogeneous catalysts, we developed various software for the design of automotive catalysts such as Ultra-Accelerated Quantum Chemical Molecular Dynamics (UA-QCMD), which is 10 million times faster than the conventional first principles molecular dynamics, mesoscopic modeling software for supported catalysts (POCO2), and mesoscopic sintering simulator (SINTA) to calculate sintering behavior of both precious metals (e.g., Pt, Pd, Rh) and supports (e.g., Al2O3, ZrO2, CeO2, or CeO2-ZrO2). We integrated the previous programs in a multiscale, multiphysics approach for the design of automotive catalysts. The method was efficient for a variety of important catalytic reactions in the scope of the automotive emission control. We demonstrated the efficiency of our approach by comparing our data with experimental results including both simple laboratory experiments and chassis dynamometer exhaust gas emission control experiments.
2016-11-08
Journal Article
2016-32-0071
Koji Ueno, Hiroyuki Horimura, Akiko Iwasa, Yuji Kurasawa, Pascaline Tran, Ye Liu
Abstract We developed a copper catalyst using zero Platinum group metals (hereafter PGMs) to fit motorcycle specific emission gas environment. Though many research reports to develop catalyst without using PGMs that are precious and costly resources are available, no reports had proven Base Metal Catalyst development to meet actual emission regulation equivalent to PGM catalysts. Compared to conventional PGM catalysts, higher temperature is required to keep high catalytic conversion efficiency by utilizing properties of this Base Metal Catalyst. Thus, this Base Metal Catalyst is located in cross coupling position, though it is rare case in motorcycle. This catalyst location could cause negative impacts on engine knocking, engine performance and drivability. This time, to overcome such negative impacts we optimized whole exhaust system, including parts around catalyst.
2016-11-08
Journal Article
2016-32-0070
Toyofumi Tsuda, Kazuya Miura, Akio Hikasa, Keiji Hosoi, Fumikazu Kimata
Abstract An exhaust gas purifying catalyst must be durable, i.e., it must maintain a sufficient catalytic performance even after thermal degradation. Therefore, large amounts of platinum group metals (PGMs), such as Pt, Pd, and Rh, should be loaded onto the catalyst substrate. Exhaust gas heat deteriorates the catalyst by sintering the PGM particles, which decreases the active surface area. It is important to reduce the PGM load and many researchers have therefore attempted to carry out PGM load reduction while maintaining sufficient durability. We found that Pt ions could form Pt-hydroxide clusters in a hexahydroxyplatinate (IV) (Pt(OH)6·H2O) nitric acid solution. The Pt-hydroxide cluster size could be controlled by varying the Pt and nitric acid concentrations and solution temperature.
2016-11-08
Journal Article
2016-32-0093
Denis Neher, Fino Scholl, Maurice Kettner, Danny Schwarz, Markus Klaissle, Blanca Giménez Olavarria
Abstract Small natural gas cogeneration engines frequently operate with lean mixture and late ignition timing to comply with NOx emission standards. Late combustion phasing is the consequence, leading to significant losses in engine efficiency. When substituting a part of the excess air with exhaust gas, heat capacity increases, thus reducing NOx emissions. Combustion phasing can be advanced, resulting in a thermodynamically more favourable heat release without increasing NOx but improving engine efficiency. In this work, the effect of replacing a part of excess air with exhaust gas was investigated first in a constant volume combustion chamber. It enabled to analyse the influence of the exhaust gas under motionless initial conditions for several relative air-fuel ratios (λ = 1.3 to 1.7). Starting from the initial value of λ, the amount of CH4 was maintained constant as a part of the excess air was replaced by exhaust gas.
2016-11-07
Article
The Administration recently announced details of the expanded network of EV charging stations across nearly 25,000 mi (40,233 km) of highways in 35 U.S. states and the District of Columbia.
2016-11-07
Article
Eliminating EV range anxiety and minimizing system costs appear to be the primary drivers behind the series-hybrid strategy, which is expected to spread to other Renault-Nissan Alliance vehicles.
2016-10-31
Article
Despite rumors of an acquisition by Apple, McLaren is racing ahead on £1B in self-funded R&D and an ambitious plan to develop an electric supercar worthy of the name.
2016-10-24
Journal Article
2016-01-9075
Martijn van Essen, Sander Gersen, Gerco van Dijk, Torsten Mundt, Howard Levinsky
Abstract The effects of air humidity on the knock characteristics of fuels are investigated in a lean-burn, high-speed medium BMEP engine fueled with a CH4 + 4.7 mole% C3H8 gas mixture. Experiments are carried out with humidity ratios ranging from 4.3 to 11 g H2O/kg dry air. The measured pressure profiles at non-knocking conditions are compared with calculated pressure profiles using a model that predicts the time-dependent in-cylinder conditions (P, T) in the test engine (“combustion phasing”). This model was extended to include the effects of humidity. The results show that the extended model accurately computes the in-cylinder pressure history when varying the water fraction in air. Increasing the water vapor content in air decreases the peak pressure and temperature significantly, which increases the measured Knock Limited Spark Timing (KLST); at 4.3 g H2O/kg dry air the KLST is 19 °CA BTDC while at 11 g H2O/kg dry air the KLST is 21 °CA BTDC for the same fuel.
2016-10-24
Journal Article
2016-01-9078
Herbert Feld, Nadine Oberender
Abstract Biodiesel contains a variety of compounds, depending on the production and the provenance of the fuel. During the production process and usage, some of these compounds can form deposits (nozzle tip deposits or internal diesel injector deposits: “IDID”), which may lead to severe problems, such as corrosion, filter blockage and other technical issues. To deal with these difficulties, it is essential to exactly determine the components of these deposits. Most analytical methods used before, require complex preparations and result in limited information of the deposit material. Using infrared microscopy (ATR-FTIR: Attenuated-Total-Reflection Fourier-Transform-Infrared-Spectroscopy) or mass spectrometry (TOF-SIMS: Time-of-Flight Secondary-Ion-Mass-Spectrometry), a direct analysis of the original deposit material is possible.
2016-10-24
Journal Article
2016-01-9079
Ryoko Sanui, Katsunori Hanamura
Time-lapse images of particulate matter (PM) deposition on diesel particulate filters (DPFs) at the PM-particle scale were obtained via field-emission scanning electron microscopy (FE-SEM). This particle scale time-series visualization showed the detailed processes of PM accumulation inside the DPF. First, PM introduced into a micro-pore of the DPF wall was deposited onto the surface of SiC grains composing the DPF, where it formed dendritic structures. The dendrite structures were locally grown at the contracted flow area between the SiC grains by accumulation of PM, ultimately constructing a bridge and closing the porous channel. To investigate the dominant parameters governing bridge formation, the filtration efficiency by Brownian diffusion and by interception obtained using theoretical filtration efficiency analysis of a spherical collector model were compared with the visualization results.
2016-10-20
Article
EPA's Christopher Grundler and expert panelists at COMVEC 2016 offered their insights on technology pathways and challenges to meeting the recently issued final greenhouse-gas standards affecting model year 2021-2027 medium- and heavy-duty on-highway vehicles.
2016-10-17
Technical Paper
2016-01-2219
Pramit Baul, Courtney Tamaro, Hrusheekesh Warpe, William Baumann, Douglas Nelson
Abstract EcoRouting refers to determining a route that minimizes vehicle energy consumption compared to traditional routing methods, which usually attempt to minimize travel time. EcoRoutes typically increase travel time and in some cases this increase may have to be constrained for the route to be viable. While significant research on EcoRouting exists for conventional vehicles, incorporating the novel aspects of plug-in hybrids opens up new areas to be explored. A prototype EcoRouting system has been developed that takes in map information and converts it to a graph of nodes containing route information such as speed and grade. The route with the minimum energy consumption is selected as the EcoRoute unless there is more than an 8% difference between the minimum time route and the EcoRoute.
2016-10-17
Technical Paper
2016-01-2215
Hubertus Ulmer, Ansgar Heilig, Simon Bensch, Timo Schulteis, Jan-Kirsten Grathwol, Felix Gollmer, Christian Hofrath, Matthias Rühl
Abstract This paper focuses on the hydraulic losses of the low-pressure diesel fuel path and the impact of these losses on the fuel consumption and therefore CO2 emissions of internal combustion engines. In this context, a 1D (one-dimensional) simulation model with implemented fluid flow physics was developed. A 3D CFD model for considering complex geometries of several fuel path components further enhances the 1D approach. Experimental data from a test bench, carrying the complete fuel pressure system, were used for validations and continuous developments of the simulation models. The results show a substantial potential of the low-pressure system regarding a reduction of CO2 emissions, depending on the control strategy of the electric fuel pump and the geometrical properties of the fuel pipes and couplings. Within the New European Driving Cycle, a potential of up to 1.1 g CO2/km was observed.
2016-10-17
Technical Paper
2016-01-2216
Brad Richard, Martha Christenson, Deborah Rosenblatt, Aaron Conde
Abstract Alternative fuels and power trains are expected to play an important role in reducing emissions of greenhouse gases (GHGs) and other pollutants. In this study, five light-duty vans, operating on alternative fuels and propulsion systems, were tested on a chassis dynamometer for emissions and efficiency. The vehicles were powered with Tier 2 gasoline, low blend ethanol (E10), compressed natural gas (CNG), liquefied petroleum gas (LPG), and an electric battery. Four test cycles were used representing city driving and cold-start (FTP-75), aggressive high speed driving (US06), free flow highway driving (HWFCT), and a combination of urban, rural, and motorway driving (WHVC). Tests were performed at a temperature of 22°C, with select tests at -7°C and -18°C. Exhaust emissions were measured and characterized including CO, NOX, THC, PM and CO2. On the FTP-75, WHVC, and US06 cycles additional exhaust emission characterization included N2O, and CH4.
2016-10-17
Technical Paper
2016-01-2231
Aras Mirfendreski, Andreas Schmid, Michael Grill, Michael Bargende
Abstract Longitudinal models are used to evaluate different vehicle-engine concepts with respect to driving behavior and emissions. The engine is generally map-based. An explicit calculation of both fluid dynamics inside the engine air path and cylinder combustion is not considered due to long computing times. Particularly for dynamic certification cycles (WLTC, US06 etc.), dynamic engine effects severely influence the quality of results. Hence, an evaluation of transient engine behavior with map-based engine models is restricted to a certain extent. The coupling of detailed 1D-engine models is an alternative, which rapidly increases the model computation time to approximately 300 times higher than that of real time. In many technical areas, the Fourier transformation (FT) method is applied, which makes it possible to represent superimposed oscillations by their sinusoidal harmonic oscillations of different orders.
2016-10-17
Technical Paper
2016-01-2249
Akash Gangwar, Abhinav Bhardawaj, Ramesh Singh, Naveen Kumar
Abstract Enhancement of combustion behavior of conventional liquid fuel using nanoscale materials of different properties is an imaginative and futuristic topic. This experiment is aimed to evaluate the performance and emission characteristics of a diesel engine when lade with nanoparticles of Cu-Zn alloy. The previous work reported the effect of metal/metal oxide or heterogeneous mixture of two or more particles; less work had been taken to analyze the homogeneous mixture of metals. This paper includes fuel properties such as density, kinematic viscosity, calorific value and performance measures like brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and emission analysis of NOX, CO, CO2, HC. For the same solid concentration, nano-fuel is compared with base fuel at different engine loads; and its effect when lade at different concentrations.
2016-10-17
Technical Paper
2016-01-2283
Stephane Zinola, Stephane Raux, Mickael Leblanc
Abstract The more and more stringent regulations on particle emissions at the vehicle tailpipe have led the car manufacturers to adopt suitable emissions control systems, like particulate filters with average filtration efficiency that can exceed 99%, including particulate mass (PM) and number (PN). However, there are still some specific operating conditions that could exhibit noticeable particle number emissions. This paper aims to identify and characterize these persistent sources of PN emissions, based on tests carried out both at the engine test bench and at the chassis dynamometer, and both for Diesel and Gasoline direct injection engines and vehicles. For Diesel engines, highest particle numbers were observed downstream of the catalyzed DPF during some operation conditions like engine warm up or filter regeneration phases.
2016-10-17
Technical Paper
2016-01-2300
Mengqin Shen, Martin Tuner, Bengt Johansson, Per Tunestal, Joakim Pagels
Abstract In order to reduce nitrogen oxides (NOx) and soot emissions while maintaining high thermal efficiency, more advanced combustion concepts have been developed over the years, such as Homogeneous Charge Compression Ignition (HCCI) and Partially Premixed Combustion (PPC), as possible combustion processes in commercial engines. Compared to HCCI, PPC has advantages of lower unburned hydrocarbon (UHC) and carbon monoxide (CO) emissions; however, due to increased fuel stratifications, soot emissions can be a challenge when adding Exhaust-Gas Recirculation (EGR) gas. The current work presents particle size distribution measurements performed from HCCI-like combustion with very early (120 CAD BTDC) to PPC combustion with late injection timing (11 CAD BTDC) at two intake oxygen rates, 21% and 15% respectively. Particle size distributions were measured using a differential mobility spectrometer DMS500.
2016-10-17
Technical Paper
2016-01-2320
Tsuyoshi Asako, Ryuji Kai, Tetsuo Toyoshima, Claus Vogt, Shogo Hirose, Shiori Nakao
Abstract Ammonia Selective Catalytic Reduction (SCR) is adapted for a variety of applications to control nitrogen oxides (NOx) in diesel engine exhaust. The most commonly used catalyst for SCR in established markets is Cu-Zeolite (CuZ) due to excellent NOx conversion and thermal durability. However, most applications in emerging markets and certain applications in established markets utilize vanadia SCR. The operating temperature is typically maintained below 550°C to avoid vanadium sublimation due to active regeneration of the diesel particulate filter (DPF), or some OEMs may eliminate the DPF because they can achieve particulate matter (PM) standard with engine tuning. Further improvement of vanadia SCR durability and NOx conversion at low exhaust gas temperatures will be required in consideration of future emission standards.
2016-10-17
Technical Paper
2016-01-2319
Kihong Kim, Rahul Mital, Takehiro Higuchi
Abstract In the previous research1), the authors discovered that the sudden pressure increase phenomenon in diesel particulate filter (DPF) was a result of soot collapse inside DPF channels. The proposed hypothesis for soot collapse was a combination of factors such as passive regeneration, high humidity, extended soak period, high soot loading and high exhaust flow rate. The passive regeneration due to in-situ NO2 and high humidity caused the straw like soot deposited inside DPF channels to take a concave shape making the collapse easier during high vehicle acceleration. It was shown that even if one of these factor was missing, the undesirable soot collapse and subsequent back pressure increase did not occur. Currently, one of the very popular NOx reduction technologies is the Selective Catalytic Reduction (SCR) on Filter which does not have any platinum group metal (PGM) in the washcoat.
2016-10-17
Technical Paper
2016-01-2314
Wanyu Sun, Shufen Wang, Yue Huang, Lei Guo, Hongzhen Li, Zhangtao Yao
Abstract The possible NOx and soot limits that a conventional diesel engine could meet without the assistance of aftertreatment system were investigated on an engineering level. A methodology combining both experiment and numerical simulation was used to evaluate favorable and unfavorable effects of various in-cylinder strategies quantitatively. These strategies or factors include combustion chamber geometry, fuel injection strategy, exhaust gas recirculation (EGR), intake valve close (IVC) timing, and turbocharger. Interactions among these strategies were paid special attention. Two steps to achieve as low as possible emissions were proposed based on analysis of these strategies. The first step would shift the NOx-soot trade-off curve closer to low emission regions via optimization of injection strategy, combustion chamber geometry, IVC, and turbocharger. As a result, NOx and soot could be simultaneously reduced by approximately 14% and 62% respectively.
2016-10-17
Technical Paper
2016-01-2354
Aaron J. Conde, Martha Christenson, Brad Richard
Abstract Tailpipe emissions, fuel consumption, and wheel torque data were measured for three pairs of vehicles tested over four drive cycles at the Emissions Research and Measurement Section of Environment and Climate Change Canada in Ottawa, Ontario. Each pair of vehicles included identical vehicle models; one vehicle was equipped with an AWD drivetrain and one vehicle was equipped with a FWD drivetrain. The AWD vehicle was tested on a double-axle chassis dynamometer. The amount of AWD activity was heavily dependent on driving behavior and AWD system design. During periods of torque delivery, the percentage of AWD activity ranged between 32% and 57% for the FTP-75 drive cycle, between 3% and 8% for the HWFCT drive cycle, and between 21% and 29% for the US06 drive cycle. The fourth drive cycle was the FTP-75 driven at -7°C. AWD distributions did not show sensitivity to temperature for the first and second vehicle models.
2016-10-17
Technical Paper
2016-01-2165
Kazuya Miyashita, Takamichi Tsukamoto, Yusei Fukuda, Katsufumi Kondo, Tetsuya Aizawa
Abstract For better understanding, model development and its validation of in-cylinder soot formation processes of Gasoline Direct Injection (GDI) engines, visualization of piston surface fuel wetting, vaporization and soot formation processes of in-cylinder pool fire via high-speed UV (266nm) and visible (445nm) laser shadowgraphy was attempted in an optically accessible Rapid Compression and Expansion Machine (RCEM). A direct-injection, spark-ignition and single-shot combustion event was achieved in the RCEM under engine-equivalent, simplified and well-defined conditions operated with engine speed 600 rpm, compression ratio 9.0, equivalence ratio 0.9 and natural aspiration. The tested fuel was composed of 70% iso-octane and 30% toluene by volume and the UV absorption by toluene enabled visualization of the in-cylinder fuel distribution.
2016-10-17
Technical Paper
2016-01-2174
Reza Golzari, Yuanping Li, Hua Zhao
Abstract As the emission regulations for internal combustion engines are becoming increasingly stringent, different solutions have been researched and developed, such as dual injection systems (combined port and direct fuel injection), split injection strategies (single and multiple direct fuel injection) and different intake air devices to generate an intense in-cylinder air motion. The aim of these systems is to improve the in-cylinder mixture preparation (in terms of homogeneity and temperature) and therefore enhance the combustion, which ultimately increases thermal efficiency and fuel economy while lowering the emissions. This paper describes the effects of dual injection systems on combustion, efficiency and emissions of a downsized single cylinder gasoline direct injection spark ignited (DISI) engine. A set of experiments has been conducted with combined port fuel and late direct fuel injection strategy in order to improve the combustion process.
2016-10-17
Technical Paper
2016-01-2169
Carrie M. Hall, James Sevik, Michael Pamminger, Thomas Wallner
Abstract The high octane rating and more plentiful domestic supply of natural gas make it an excellent alternative to gasoline. Recent studies have shown that using natural gas in dual fuel engines provides one possible strategy for leveraging the advantages of both natural gas and gasoline. In particular, such engines been able to improve overall engine efficiencies and load capacity when they leverage direct injection of the natural gas fuel. While the benefits of these engine concepts are still being explored, differences in fuel composition, combustion process and in-cylinder mixing could lead to dramatically different emissions which can substantially impact the effectiveness of the engine’s exhaust aftertreatment system. In order to explore this topic, this study examined the variations in speciated hydrocarbon emissions which occur for different fuel blends of E10 and compressed natural gas and for different fuel injection strategies on a spark-ignition engine.
2016-10-17
Technical Paper
2016-01-2185
Jialin Liu, Hu Wang, Zunqing Zheng, Zeyu Zou, Mingfa Yao
Abstract In this work, both the ‘SCR-only’ and ‘EGR+SCR’ technical routes are compared and evaluated after the optimizations of both injection strategy and turbocharging system over the World Harmonized Stationary Cycle (WHSC) in a heavy duty diesel engine. The exhaust emissions and fuel economy performance of different turbocharging systems, including wastegate turbocharger (WGT), variable geometry turbocharger (VGT), two-stage fixed geometry turbocharger (WGT+FGT) and two-stage variable geometry turbocharger (VGT+FGT), are investigated over a wide EGR range. The NOx reduction methods and EGR introduction strategies for different turbocharger systems are proposed to improve the fuel economy. The requirement on turbocharging system and their potential to meet future stringent NOx and soot emission regulations are also discussed in this paper.
2016-10-17
Technical Paper
2016-01-2187
Haifeng Liu, Huixiang Zhang, Hu Wang, Xian Zou, Mingfa Yao
Abstract The combustion in low-speed two-stroke marine diesel engines can be characterized as large spatial and temporal scales combustion. One of the most effective measures to reduce NOx emissions is to reduce the local maximum combustion temperature. In the current study, multi-dimensional numerical simulations have been conducted to explore the potential of Miller cycle, high compression ratio coupled with EGR (Exhaust Gas Recirculation) and WEF (water emulsified fuel) to improve the trade-off relationship of NOx-ISFC (indicated specific fuel consumption) in a low-speed two-stroke marine engine. The results show that the EGR ratio could be reduced combined with WEF to meet the Tier III emission regulation. The penalty on fuel consumption with EGR and WEF could be offset by Miller cycle and high geometric compression ratio.
2016-10-17
Technical Paper
2016-01-2213
Tomoaki Ito, Makoto Nagata
Abstract Diesel exhaust emission control systems often contain DOC (Diesel Oxidation Catalyst) + CSF (Catalyzed Soot Filter) components. In this system PM (particulate matter) is filtered and accumulated in the CSF and such filtered PM is periodically combusted by supplying heat to the CSF. The heat to CSF is generated within the DOC by an exothermic reaction with extra fuel supplied to the DOC. Here the exothermic performance of DOC depends on not only the active catalytic site (such as Pt and/or Pd) but also on the characteristics of the porous material supporting the precious metals. Various properties of Al2O3, i.e. pore diameter, pore volume, BET surface area, acidity, basicity and the Ea (activation energy) of fuel combustion, used in DOCs and PGM particle size of each DOC were measured. The fuel combustion performance of each DOC was evaluated by diesel engine bench.
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