Criteria

Text:
Display:

Results

Viewing 1 to 30 of 107770
2016-10-24
Journal Article
2016-01-9075
Martijn van Essen, Sander Gersen, Gerco van Dijk, Torsten Mundt, Howard Levinsky
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
2016-01-9076
Ulas Yildirim, Renee Webster, David Evans, Paul Rawson
Abstract Aviation turbine fuel and diesel fuel were blended with synthetic paraffins produced via two pathways and the combustion properties measured. Both aviation and diesel fuel containing synthetics produced from the fermentation of sugars, had a linear response to blending with decreasing ignition delay times from 5.05 - 3.52 ms for F-34 and 3.84 - 3.52 ms for F-76. For the same fuels blended with synthetics produced from the fermentation of alcohols, ignition delay times were increased out to 18.66 ms. The derived cetane number of the blends followed an inversely similar trend. Additionally, distillation using ASTM D2287 at high synthetic paraffinic kerosene blend ratios resulted in the recovery temperatures being incorrectly reported. In this case, higher recovery volumes were at lower temperatures than earlier recovery points i.e. T90< T50, for SIP-SPK
2016-10-17
Technical Paper
2016-01-2154
Ary Armando Alvarez, Eufemio Muñoz
The EcoCAR3 team of California State University, Los Angeles is designing a Parallel Post Transmission Plug-in Hybrid Electric Vehicle (PPT PHEV) that will maintain consumer acceptability in the areas of performance, utility and safety with the end-goal of reducing Well-to-Wheel Green House Gas (WTW GHG) emissions and Well-to-Wheel Petroleum Energy Use (WTW PEU). The team utilizes the 2016 Chevrolet Camaro platform with modifications such as 2.4L Ecotec engine, a 134 HP electric motor and a 12.6 KW/h battery pack. The vehicle is estimated to have a fuel economy of 58.7 miles per gallon gasoline equivalent (mpgge). This paper presents the vehicle’s two main operating modes, Electric Vehicle (EV) and Hybrid-Electric Vehicle (HEV) while performing Environmental Protection Agency (EPA) certified drive cycles: 505, HWFET, US06 City and US06 HWY.
2016-10-17
Technical Paper
2016-01-2153
Hubertus Ulmer, Ansgar Heilig, Matthias Rühl, Boris Löw
The calibration process of modern combustion engines is characterized by a wide range of experimental test runs. Whereas in the past mainly standardized test bench runs were carried out, the new Worldwide Harmonized Light Vehicles Test Procedure (WLTP) and real drive emissions will require additional experimental efforts. In order to provide solutions for a time and cost efficient calibration process, Bertrandt has developed in the work of Burggraf [BUR15] an innovative optimization algorithm. While common Design of Experiments (DOE) optimization approaches are usually based on stationary engine operation points, the Bertrandt tool b.eco (Bertrandt. Engine Calibration Optimization) uses a quasi-stationary measurement procedure. The time necessary for establishing a steady state of the engine can thus be omitted. On the one hand, this leads consequently to a general reduction of time.
2016-10-17
Technical Paper
2016-01-2157
Huiyan Zhang, Lei Shi
The three-phase sequential turbocharging(ST) system with two unequal-size turbochargers is developed to improve the fuel economy performance and reduce the smoke emission of the automotive diesel engine, which has wider range of application than the current two-phase sequential turbocharging system. However, it results in greater difficulty in obtaining strategies because of control variables increasing and more complicated transient control strategies under frequently changing operating conditions. The present work aims to optimize the control schemes of bypass valve of turbine and fuel injection to improve the transient performance. A mathematical model of optimal control expressing the relationship between ST system parameters and engine performance is established, then a mean value model for diesel engine is built and verified by engine tests for transient process in SIMULINK environment.
2016-10-17
Technical Paper
2016-01-2156
Christian Friedrich, Matthias Auer, Gunnar Stiesch
Due to the increasing number of engine setting parameters to be optimized, model based calibration techniques have been introduced to medium speed engine testing to keep the number of engine tests low. Polynomials in combination with d-optimal test plans have been proven to be a good choice for modeling the stationary behavior of selected engine outputs. Model approaches like artificial neural networks (ANNs) have been rarely used for medium speed purposes since they require quite high amounts of testing data for model training. To evaluate the potential of these model approaches radial basis function networks, a subclass of neural networks, as well as Gaussian processes have been investigated as alternatives to polynomials. A manageable amount of tests according to an adapted d-optimal test plan was carried out at a test bench.
2016-10-17
Technical Paper
2016-01-2162
Lewis Gene Clark, Sanghoon Kook, Qing Nian Chan, Evatt R. Hawkes
One major drawback of spark-ignition direct-injection (SIDI) engines is increased particulate matter (PM) and unburned hydrocarbon emissions at high load, due to wall wetting and a reduction in available air/fuel mixing time when compared to port-fuel injection (PFI). It is therefore necessary to understand the mechanics behind injection strategies which are capable of reducing emissions while also maintaining the performance and efficiency of the engine. This study investigates the effect of varying the number and duration of fuel injection events on the operation of a wall-guided spark-ignition direct-injection engine. Performance parameters derived from in-cylinder pressure data are analysed alongside high speed natural flame chemiluminescence images in order to obtain relationships between engine output and the physical properties associated with air/fuel mixing and flame propagation.
2016-10-17
Technical Paper
2016-01-2163
Claudius Schueck, Thomas Koch, Wolfgang Samenfink, Erik Schuenemann, Stephan Tafel, Oliver Towae
Despite the known benefits of direct injection spark ignition engines, port fuel injection (PFI) remains a highly relevant injection concept, especially for cost sensitive market segments. Since particulate number (PN) emissions limits can be expected also for PFI SI engines in future emissions legislations, it is necessary to understand the soot formation mechanisms and possible counter-measures. Several experimental studies demonstrated an advantage for PFI SI engines in terms of PN emissions compared to DI. In this paper an extended focus on higher engine loads for future test cycles or real driving emissions testing (RDE) is applied. The combination of operating parameter studies and optical analysis by high-speed video endoscopy on a four-cylinder turbocharged SI engine allows a profound understanding of relevant soot formation mechanisms.
2016-10-17
Technical Paper
2016-01-2164
Guillaume Pilla, Olivier Laget, Rajesh kumar, Loic De Francqueville
Reduction of CO2 emissions is becoming one of the great challenges for future gasoline engines. Downsizing is one of the most promising strategy to achieve this reduction, though it facilitates occurrence of knocking. Therefore downsizing has to be associated with knock limiting technologies such as modified aerodynamics, dilution of air-fuel mixture, compression ratio limitation, intake camshaft strategies (Miller / Atkinson cycle) and other thermal management adaptations. The aim of the current research program is to use the octane number as a tuning parameter to simultaneously make the engine more efficient and reduce CO2 emissions. The idea is to prevent knock occurrence by adapting the fuel RON injected in the combustion chamber. Thus, the engine cycle efficiency is increased by keeping combustion phasing at optimum. This is achieved by a dual fuel injection strategy, involving a low-RON base fuel and a high-RON octane booster.
2016-10-17
Technical Paper
2016-01-2165
Kazuya Miyashita, Takamichi Tsukamoto, Yusei Fukuda, Katsufumi Kondo, Tetsuya Aizawa
For better understanding of in-cylinder soot formation processes of Gasoline Direct Injection (GDI) engines, visualization via high-speed UV (266nm) and visible (445nm) laser shadowgraphy of piston surface fuel wetting, vaporization and soot formation processes of in-cylinder pool fire was attempted in a Rapid Compression and Expansion Machine (RCEM). A direct-injection, spark-ignition and single-shot combustion event was achieved in the RCEM 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. Significant UV absorption was caused also by in-cylinder soot particles, which was reasonably distinguishable from the fuel by comparing the UV shadowgraphs with visible shadowgraphs and direct photographs of soot taken under identical conditions.
2016-10-17
Technical Paper
2016-01-2166
Ahfaz Ahmed, Muhammad WAQAS, Nimal Naser, Eshan Singh, William Roberts, Sukho Chung, Mani Sarathy
Commercial gasoline fuels contain hundreds of different hydrocarbons, yet despite their dissimilarity in composition they often demonstrate similar octane ratings. It is of fundamental interest to study differences arising in combustion performance of such fuels, specifically fuels have varying physical properties. This investigation is needed to interpret differences in combustion behavior of gasolines showing similar knocking character in a cooperative fuel research engine, but demonstrating different attributes in a direct injection spark ignition (DISI) engines due to the enhanced effects of fuel properties To investigate this scenario two FACE (Fuels for advanced combustion engines) gasolines, FACE F and FACE G with similar Research and Motor octane but differing physical and chemical properties were studied in a DISI engines.
2016-10-17
Technical Paper
2016-01-2167
Kohtaro Hashimoto, Tomohide Kudo, Takuya Sato, Ichiro Takase PhD, Takamasa Suzuki PhD, Tatsuya Nakano PhD
In order to develop the on-board gasoline reforming technology that provides higher octane number fuel on demand, octane number enhancement of gasoline surrogate by aerobic oxidation using nitroxy imide catalyst was investigated. At first, octane number of the oxidative species from alkane and aromatic compound were estimated using fuel ignition analyzer. As a result, not only alcohols but also ketones and aldehydes have higher octane number than the original alkanes and aromatic compound. Then, gasoline surrogate was oxidized aerobically with nitroxy imide catalyst and cobalt catalyst under lower than 100degree C condition. As a result, fuel molecules were oxidized to produce alcohols, ketones, aldehydes, and ‎carboxylic acids. Nitroxy imide catalyst that has higher solubility in gasoline surrogate has higher oxidation ability. Furthermore, the estimated octane number of the oxidized gasoline surrogate improves 16 RON.
2016-10-17
Technical Paper
2016-01-2168
Masaharu Kassai, Taisuke Shiraishi, Toru Noda, Mamoru Hirabe, Yoshiki Wakabayashi, Jin Kusaka, Yasuhiro Daisho
For the development of downsized spark ignition (SI) engine, an abnormal combustion issue which is called low speed pre-ignition(LSPI) was recognized and desired to be solved. To explain the too early pre-ignition timing in LSPI, we need to assume some pre-ignition source which is containing something other than fuel. Previously, it have been reported that LSPI can be caused by droplets of fuel and lubricant oil mixture. In this report, ignition behavior of lubricant component containing fuel injected toward premixed fuel-air mixture was experimentally investigated by using rapid compression and expansion machine (RCEM) which can visualize combustion process in cylinder. Various combinations of fuel composition for premixed fuel-air mixture and fraction of base oil, metallic additives, and fuel for injecting droplets were tested.
2016-10-17
Technical Paper
2016-01-2169
Carrie M. Hall, James Sevik, Michael Pamminger, Thomas Wallner
The high octane rating and more plentiful domestic supply of natural gas make it an excellent alternative to gasoline. Using natural gas in dual fuel engines provides one possible strategy for leveraging the advantages of both natural gas and gasoline and such engines have shown the potential to improve overall engine efficiencies. While the benefits of these engine structures are still being explored, one concern with natural gas combustion is its tendency for more incomplete combustion particularly when direct injected. Because of such combustion differences, pollutant formation may vary dramatically for different blends of gasoline and natural gas. This study explores the variations in speciated hydrocarbon emissions which occur for different fuel blends of E10 and compressed natural gas and for different fuel injection strategies.
2016-10-17
Technical Paper
2016-01-2171
Vallinayagam Raman, Vedharaj Sivasankaralingam, Robert dibble, S. Mani Sarathy
Most prominent biofuels contain oxygen (e.g., ethanol, methanol, and ethers) and thus have lower energy density compared to hydrocarbon fuels. This limitation poses a problem of increased volumetric fuel consumption when being used in engines. Avoiding this limitation, this study proposes a novel biofuel, pinene (C10H16), which does not contain oxygen and thus an energy density comparable to hydrocarbon fuels. The ignition characteristics of pinene were evaluated in an ignition quality tester (IQT). IQT determined ignition delay time (IDT) of pinene is 10.5 ms, which is lower than that of iso-octane, 17.9 ms. From IQT results, we estimate a research octane number (RON) of pinene as 85. The variation of IDT with respect to temperature show that pinene is less reactive at low temperature, but more reactive at high temperature than isooctane. These results suggest that pinene has high octane sensitivity and is suitable for operation in SI engines.
2016-10-17
Technical Paper
2016-01-2170
Raphael Gukelberger, Dennis Robertson, Terrence Alger, Jess Gingrich, Steven Almaraz, Vijayakannan MOHAN
A turbocharged 2.0 L PFI engine was modified to operate in a low-pressure loop and Dedicated EGR (D-EGR®) engine configuration. Both engine architectures were operated with a low and high octane gasoline as well as three ethanol blends. The core of this study focused on examining combustion differences at part and high loads between the selected fuels and also the different engine configurations. Specifically, the impact of the fuels on combustion stability, burn rates, knock mitigation, required ignition energy, and efficiency were evaluated. The results showed that the knock resistance generally followed the octane rating of the fuel. At part loads, the burn rates, combustion stability, and EGR tolerance was marginally improved with the high ethanol blends. When combustion was not knock or stability limited, the efficiency differences between the fuels were negligible. The D-EGR engine was much less sensitive to fuel changes in terms of burn rates than the LPL EGR setup.
2016-10-17
Technical Paper
2016-01-2173
Hiroshi Hanabusa, Takashi Kondo, Kohtaro Hashimoto, Masahiro Furutani
It is known that lean combustion is effective as one of the way which improves thermal efficiency of gasoline engine. It is necessary to reduce combustion cyclic variations through the use of a leaner mixture for the furthering high efficiency of lean combustion, and in addition to nitrogen oxides emission reduction is also an issue. In this study, combustion analysis was carried out focusing on cyclic variations of the heat release of lean combustion. Since the initial flame kernel growth speed had a great effect on both the indicated mean effective pressure and the in-cylinder’s maximum temperature, with correlation to NOx emission, laminar flame speed around the spark plug was analyzed. Infrared absorption spectrophotometry was used for the measurement of a fuel concentration around the spark plug.
2016-10-17
Technical Paper
2016-01-2172
Matthieu Cordier, Olivier Laget, Florence Duffour, Xavier Gautrot, Loic De Francqueville
Increasing global efficiency of direct injection spark ignition (DISI) engine is nowadays one of the main concerns in automotive research. Emissions regulations such as EURO6+ are more and more stringent and automotive industry needs to comply with objective of greenhouse gas production to limit global warming phenomenon. Currently, the conventional way to reduce DISI engine fuel consumption is the Downsizing. This approach is well suited to the current homologation cycle as NEDC, but has the drawback to induce strong over-consumptions in the frame of customer real driving usage. Moreover, the driving cycles dedicated to EURO 7 and future regulations will evolve towards usage ranges including higher load operations with higher particulate emissions. Consequently, limitations in terms of emitted particles will be especially as constraining.
2016-10-17
Technical Paper
2016-01-2175
Shui Yu, Kelvin Xie, Xiao Yu, Meiping Wang, Ming Zheng, Xiaoye Han, Jimi Tjong
Future clean combustion engines are tending to employ overall lean and diluted mixtures under low temperature combustion along with intensified cylinder charge motion. The diluted cylinder charge causes slower ignition flame propagation and thus an instable combustion phasing. Furthermore, the ignition robustness need to be improved to expand the dilution tolerance thereby allowing a wider engine operation range. In this paper, advanced high energy ignition strategies are investigated on both optical combustion vessels and a single cylinder engine. The implemented ignition strategies include multi-coil high energy ignition via a novel multipole igniter, pre-chamber flame jet spark plug ignition, and high frequency active resonant corona ignition.
2016-10-17
Technical Paper
2016-01-2174
Reza Golzari, Yuanping Li, Hua Zhao
As the emission regulations for internal combustion engines are becoming increasingly stringent, different solutions have been researched and developed, such as downsizing combined with single and multistage boosting (turbocharging and/or supercharging), dual injection and fuelling systems, variable valve timing and lift devices, variable compression and expansion ratio using Miller and Atkinson cycles. The aim of these systems is to improve the in-cylinder mixture quality 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 equipped with variable cam phasing on both the intake and exhaust cams.
2016-10-17
Technical Paper
2016-01-2177
Kevin L. Hoag, Barrett Mangold, Terrence Alger, Zainal Abidin, Christopher Wray, Mark Walls, Christopher Chadwell
A unique single cylinder engine was used to assess engine performance and combustion characteristics at three different strokes, with all other variables held constant. The engine utilized a production four-valve, pentroof cylinder head with an 86mm bore. The stock piston was used, and a variable deck height design allowed three crankshafts with strokes of 86, 98, and 115mm to be tested. The compression ratio was also held constant. The engine was run with a controlled boost-to-backpressure ratio to simulate turbocharged operation, and the valve events were optimized for each operating condition using intake and exhaust cam phasers. EGR rates were swept from zero to twenty percent under low and high speed conditions, at MBT and maximum retard ignition timings. The increased stroke engines demonstrated efficiency gains under all operating conditions, as well measurably reduced 10-to-90 percent burn durations.
2016-10-17
Technical Paper
2016-01-2176
Moritz Schumacher, Michael Wensing
Pre-chamber ignition systems enable the combustion of homogeneous lean mixtures in internal combustion engines with significantly increased thermal efficiency. Such ignition systems provide a much higher ignition energy compared to a common spark ignition by burning a small portion of the charge in a separate chamber, generating multiple ignition sites in the main combustion chamber and increasing the turbulent flame speed. Pre-chamber ignition systems are commonly used in large natural gas engines but the integration in automotive engines is not feasible so far due to the lack of suitable fuelling systems needed to keep the pre-chamber mixture stoichiometric at lean operation of the engine. Based on preliminary investigations we developed an ignition system with fuelled pre-chamber for automotive engines utilizing the available space for the conventional spark plug.
2016-10-17
Technical Paper
2016-01-2179
Marius Zubel, Om Parkash Bhardwaj, Benedikt Heuser, Bastian Holderbaum, Sebastian Doerr, Jukka Nuottimäki
The present work represents a continuation of the earlier results published by the authors on combustion and emission investigation of neat Hydrogenated Vegetable Oil (HVO) in a High Efficiency Diesel Combustion System (SAE Int. J. Fuels Lubr.: 2013-01-1677, 2014-01-2846). The results indicate a significant reduction in CO-, HC- and Noise emissions at constant NOx levels. With regards to soot emissions, at higher part loads the aromatic free, paraffinic composition of HVO shows a significant reduction than EN 590 petroleum Diesel but at lower loads the high cetane number leads to shorter ignition delays, and therefore, ignition under richer conditions caused slightly increased soot emissions. This drawback could be compensated with an optimized engine calibration but in this work, an advanced fuel formulation approach is investigated to further improve the emission behavior.
2016-10-17
Technical Paper
2016-01-2178
Daniela Siano, Gerardo Valentino, Fabio Bozza, Arturo Iacobacci, Luca Marchitto
In this paper, a downsized twin-cylinder turbocharged spark-ignition engine is experimentally investigated at test-bench in order to verify the potential to estimate the peak pressure value and the related crank angle position based on vibrational data acquired by an accelerometer sensor. Purpose of the activity is to provide the ECU of additional information to establish a closed-loop control of the spark timing, on a cycle-by-cycle and cylinder-by-cylinder basis. In this way, an optimal combustion phasing can be more properly accomplished in each engine operating condition. Vibrational data are also employed to have information on cycle-by-cycle variations (CCVs) of the pressure peak. More sophisticated techniques for the control of the cycle dispersion are also foreseen. To this aim, engine behavior is firstly characterized in terms of average thermodynamic and performance parameters and CCVs at high-load operation.
2016-10-17
Technical Paper
2016-01-2181
Yong Qian, Yahui Zhang, Liang Yu, Zhen Huang, Xing-cai Lu
In this paper, an experimental study based on a modified single cylinder diesel oil engine has been conducted to study the effects of diesel oil blending different iso-alkanes on the combustion and emissions. Iso-octane, iso-dodecane and 2,2,4,4,6,8,8-Heptamethylnonane (HMN) were chosen as iso-alkanes. During the experiment, the direct injection timing was kept at 7 oCA BTDC, and the injection pressure was maintained at 120MPa. The study found that after blending iso-alkanes, the changes of fuel physical properties have significant effects on the heat release phase under low load. However, the effects are weakened gradually with the improvement of loads. The peak value of heat release curves and the maximum pressure rising rate gradually increase with the improvement of loads after mixing with iso-alkanes.
2016-10-17
Technical Paper
2016-01-2180
Vedharaj Sivasankaralingam, Vallinayagam Raman, mohammed jaasim Mubarak ali, Adamu Alfazazi, Tianfeng Lu, Hong Im, S. Mani Sarathy, Robert dibble
The auto ignition behavior of diethyl ether (DEE) in ethanol was investigated in CI engine both numerically and experimentally. While DEE has a higher cetane number of 139, ethanol exhibits poor ignition characteristics with a cetane number of 8. Therefore, DEE was used as an ignition promoter for the operation of ethanol in CI engine. Mixtures of DEE and ethanol (DE) such as DE75 (75% DEE + 25% ethanol), DE50 (50% DEE + 50% ethanol) and DE25 (25% DEE + 75% ethanol) were tested in a CI engine. While DE75 and DE50 autoignited at an inlet air pressure of 1.5 bar, DE25 failed to autoignite even at boosted conditions up to 2 bar. The peak in-cylinder pressures for diesel and DE75 were comparable, while DE50 showed reduced peak in-cylinder pressure with delayed start of combustion (SOC). The combined effect of high reactivity of DEE and the autoignition suppression of ethanol were also numerically investigated.
2016-10-17
Technical Paper
2016-01-2184
Manuel A. Gonzalez D, Davide Di Nunno
Future more stringent requirements for emissions reductions and higher fuel economy require more efficient higher energy extraction in the cylinder, trending to lower exhaust gas temperatures, challenging the energy availability for after treatment components. Methods are required to increase the efficiency of the exhaust thermal management, and Internal Exhaust Gas Recirculation (I-EGR) can increase the exhaust temperature in favor of earlier after treatment activation or for maintaining sustained higher after treatment efficiencies. I-EGR capability has been studied in a Diesel engine through the secondary opening of exhaust valves for more efficient recirculation of exhaust gases from a previous engine cycle to the cylinder mass charge during the intake stroke. I-EGR alone could increase exhaust gas temperature up to a limit soot emissions.
2016-10-17
Technical Paper
2016-01-2186
Prakash Narayanan Arunachalam, Marcus Thern, Per Tunestal, Martin Tuner
Humid air motor (HAM) is an engine operated with humidified inlet charge. System simulations study on HAM showed the waste heat recovery potential over conventional system. To comprehend the potential benefits in real-time, an HAM setup was constructed. The HAM setup was built around a 13-litre six cylinder Volvo diesel engine. The HAM engine process is explained in detail in this paper. Emission analysis is also performed for all three modes of operation. The experiments were carried out at part load operating point of the engine to understand the effects of humidified charge on combustion, efficiency and emissions. Experiments were conducted without EGR, with EGR and with humidified inlet charge. These three modes of operation furnished the potential benefits of each system. Exhaust heat is used for partial humidification process. Results shows that HAM operation without compromising on efficiency reduces the NOx and soot significantly over the EGR operated engine.
2016-10-17
Technical Paper
2016-01-2187
Haifeng Liu, Huixiang Zhang, Hu Wang, Xian Zou
In order to meet the IMO Tier III nitrogen oxide (NOX) emission regulations and find a feasible solution, large two-stroke slow speed marine engine are studied. 1-D engine working cycle simulation and 3-D CFD simulation models were established and calibrated against the experiment data for 75% load operation at 112r/min. The models were conducted to predict the performance and emissions for the engine under different exhaust valve close timings, intake pressures and EGR rates. The simulated results indicate that the variation of Miller timings can effectively decrease the region of high temperature and improve the levels and trade-off relationship of NOX and soot. However, the negative effect of Miller cycle brings the deficiency of fresh charge .It is essential to combine the Miller cycle with two-stage turbo charging .It is found that high boost pressure with EGR could further decrease the amount of NOX .In addition ,both NOX and soot can decrease when fuel-air ratio is constant.
2016-10-17
Technical Paper
2016-01-2190
Qi Shi, Tie Li, Xiaoqing Zhang, Bin Wang, Ming Zheng
Taking advantage of high speed RGB video cameras, the two-color method can be implemented with a relatively simple setup to obtain the temporal development of the two dimensional temperature and soot (KL) distributions in a reacting diesel jet. However, several issues such as selection of the two wavelength lights, the role of bandpass filters, and available measuring range, etc. should be known to obtain a reliable measurement. This paper, at first, discusses about the uncertainties in the measurement of temperature and KL distributions in the diesel flame by the two-color method using the high speed RGB video camera. Since butanol, as an alternative renewable fuel, has potentials in application in diesel engines, the characteristics of spray combustion of diesel-butanol blends under the diesel-like ambient conditions in a pre-burning constant-volume combustion chamber is studied.
Viewing 1 to 30 of 107770