Display:

Results

Viewing 1 to 30 of 57666
2017-10-24
Journal Article
2017-01-9378
Eric Kurtz, Christopher J. Polonowski
Abstract The design of modern diesel-powered vehicles involves optimization and balancing of trade-offs for fuel efficiency, emissions, and noise. To meet increasingly stringent emission regulations, diesel powertrains employ aftertreatment devices to control nitrogen oxides, hydrocarbons, carbon monoxide, and particulate matter emissions and use active exhaust warm-up strategies to ensure those devices are active as quickly as possible. A typical strategy for exhaust warm-up is to operate with retarded combustion phasing, limited by combustion stability and HC emissions. The amount of exhaust enthalpy available for catalyst light-off is limited by the extent to which combustion phasing can be retarded. Diesel cetane number (CN), a measure of fuel ignition quality, has an influence on combustion stability at retarded combustion phasing. Diesel fuel in the United States tends to have a lower CN (both minimum required and average in market) than other countries.
2017-10-08
Technical Paper
2017-01-2197
Vignesh Pandian Muthuramalingam, Anders Karlsson
Owing to increased interest in blended fuels for automotive applications, a great deal of understanding is sought for the behavior of multicomponent fuel sprays. This sets a new requirement on spray model since the volatility of the fuel components in a blend can vary substantially. It calls for careful solution to implement the differential evaporation process concerning thermodynamic equilibrium while maintaining a robust solution. This work presents the Volvo Stochastic Blob and Bubble (VSB2) spray model for multicomponent fuels. A direct numerical method is used to calculate the evaporation of multicomponent fuel droplets. The multicomponent fuel model is implemented into OpenFoam CFD code and the case simulated is a constant volume combustion vessel. The CFD code is used to calculate liquid penetration length for surrogate diesel (n-dodecane)-gasoline (iso-octane) blend and the result is compared with experimental data.
2017-10-08
Technical Paper
2017-01-2198
Zhihong Li, Guoxiu Li, Lan Wang, Hongmeng Li, Jie Wang, Haizhou Guo, Shuangyi He
The electromagnetic valve driving mechanism is the significant equipment, which plays a vital role in the unit pump injection system; therefore, the performance of the electromagnetic valve directly influences the function of the control system. Based on the operation conditions of the unit pump injection system, a steady electromagnetic valve model was modified to study the influence factors of electromagnetic force and the best combination to get the maximum electromagnetic force. The validation model was verified by experiment. The effects of some crucial parameters upon the electromagnetic force were investigated in the present paper, (including working airspace, magnetic pole’s cross-sectional area, coil position, coil turn, the armature thickness). The result shows that the electromagnetic force of the solenoid valve enhanced with the increasing driving current and reduced with the decreasing of working condition.
2017-10-08
Technical Paper
2017-01-2405
Christophe Chaillou, Alexandre Bouet, Arnaud Frobert, Florence Duffour
Fuels from crude oil are the main energy vectors used in the transport sector but these fuels associated to CI engines are nowadays often criticized. Nevertheless, engine and fuel co-research is one of the main leverage to reduce both CO2 footprint and criteria pollutants. CI engines, with gasoline-like fuels, are a promising way for NOx and particulates emission abatement while keeping lower CO2 emission. To introduce a new fuel/engine technology, investigations of pollutants are mandatory. Previous work [1] already studied the behavior of low RON gasoline soot generated with a CI engine. The aim of this paper is to assess the impact of such fuel/engine technology on the HC emissions and on the DOC behavior. HC speciation is performed upstream and downstream DOC. Warm-up and efficiency are also tested for different operating conditions. Then, exothermal capacities are considered to ensure high level of temperature for DPF regeneration.
2017-10-08
Technical Paper
2017-01-2268
Zhanming Chen, Long Wang, Tiancong Zhang, Qimeng Duan, Bo Yang
Liquefied natural gas (LNG) fuelled engines have been widely equipped on heavy duty vehicles both for fuel-economic and environmental protection concerns, however, they always suffer from deteriorated combustion performance and flame stability due to relatively low burning velocity of methane for lean mixture. In this paper, experimental study was conducted on a turbo-charged, spark-ignition, lean-burn LNG engine with methanol port injection. The combustion characteristics such as cylinder pressure traces, heat release rate (HRR), mass fraction burned (MFB), ignition delay, centroid of heat release, position of CA50 and CA90, as well as cyclic variation of peak pressure were analysed under light load (BMEP=0.3876MPa) with different methanol substitution rates (MSR=0%, 5.2%, 10.2%, 17.2%). The experimental results show that combustion phase advanced with increment of MSR due to faster burning velocity of methanol.
2017-10-08
Technical Paper
2017-01-2223
Vikram Singh, Per Tunestal, Martin Tuner
In recent years, stricter regulations on emissions and higher demands for more fuel efficient vehicles have led to a greater focus on increasing the efficiency of the internal combustion engine. Nowadays, there is increasing interest in the recovery of waste heat from different engine sources such as the coolant and exhaust gases using, for example, a Rankine cycle. In diesel engines 15% to 30% of the energy from the fuel can be lost to the coolant and hence, does not contribute to producing work on the piston. This paper looks at reducing the heat losses to the coolant by increasing coolant temperatures within a single cylinder Scania D13 engine and studying the effects of this on the energy balance within the engine as well as the combustion characteristics. To do this, a GT Power model was first validated against experimental data from the engine.
2017-10-08
Technical Paper
2017-01-2286
A S Ramadhas, Punit Kumar Singh, Reji Mathai, Ajay Kumar Sehgal
Ambient temperature conditions, engine design, fuel, lubricant and fuel injection strategies influence the cold start performance of gasoline engines. Despite the cold start period is only a very small portion in the legislative emission driving cycle, but it accounts for a major portion of the overall driving cycle emissions. The start ability tests were carried out in the weather controlled transient dynamometer - engine test cell at different ambient conditions for investigating the cold start behavior of a modern generation multi-point fuel injection system spark ignition engine. The combustion data were analyzed for the first 200 cycles and the engine performance and emissions were analyzed for 300 s from key-on. It is observed that cumulative fuel consumption of the engine during the first 60 s of cold starting at 10 °C was 60% higher than at 25 °C and resulted in 8% increase in the value of peak speed of the engine.
2017-10-08
Technical Paper
2017-01-2369
Prakash Arunachalam, Martin Tuner, Per Tunestal, Marcus Thern
Humid air motor (HAM) is an engine operated with humidified inlet charge. System simulations study on HAM showed the waste heat recovery potential over a conventional system. An HAM setup was constructed, to comprehend the potential benefits in real-time, 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 provided the potential benefits of each system. Exhaust heat was used for partial humidification process. Results show that HAM operation, without compromising on efficiency, reduces NOx and soot significantly over the engine operated without EGR.
2017-10-08
Technical Paper
2017-01-2422
Na Li, Fenlian Huang, Yuhua Bi, Yueqiang Xu, Lizhong Shen, Dewen Jia
The assembly of connecting rod bearing and crankpin is a key friction pair which offers an important guarantee for stable operation of diesel engine. Specific to the non-road 2-cylinder diesel engine developed independently and based on the theory of elasto-hydrodynamic lubrication as well as multi-body dynamics, this paper establishes a multi-body dynamics model for connecting rod bearing of the 2D25 horizontal diesel engine and makes a research on the influence of bearing width, bearing clearance, and oil inlet position and diameter upon lubrication of connecting rod bearing, taking into consideration that of the surface appearance of bearing bush and the elastic deformation of bearing bush and axle journal upon the same. Research results show that bearing width and bearing clearance are the major factors that influence lubrication characteristics of connecting rod bearing while oil inlet position and diameter only have a small influence on such characteristics.
2017-10-08
Technical Paper
2017-01-2384
Ijhar H. Rusli, Svetlana Aleksandrova, Humberto Medina, Stephen F. Benjamin
The effect of the residual swirl from the turbocharger turbine on the catalyst flow distribution has been investigated experimentally and numerically. A swirling flow rig with a moving-block swirl generator was used to generate swirling flow in a sudden expansion diffuser with a wash-coated diesel oxidation catalyst (DOC) downstream. Hot-wire anemometry (HWA) was used to measure the axial and tangential velocities of the swirling flow upstream of the diffuser expansion and the axial velocity downstream the monolith. Pressure along the diffuser wall was measured using Scanivalve pressure scanners. With no swirl, the results show that the flow is highly non-uniform in the catalyst monolith with maximum velocities near the diffuser axis. High non-uniformity is also exhibited at high swirl levels with highest velocities near the diffuser wall. An intermediate swirl level exists where the flow is uniform.
2017-10-08
Technical Paper
2017-01-2382
Tul Suthiprasert, Sirichai Jirawongnuson, Ekathai Wirojsakunchai, Tanet Aroonsrisopon, Krisada Wannatong, Atsawin Salee
One of the most important challenges on implementing Diesel Dual Fuel (DDF) engine into the vast market is CH4 emission in its exhaust. This is due to the fact that CH4 is hard to oxidize at lower temperature environment of DDF exhaust comparing to that of conventional or bi-fuel engines. In addition, another parameter such as exhaust flow rate, specie concentration, especially CO, C3H8, and water have tremendous impact on Diesel Oxidation Catalyst performance on reducing CH4. Combining of all these factors together, a study of CH4 reduction is a major research problems that researchers around the world are keen to gain more fundamental understandings. In this work, a new CH4 kinetic model, which is based on Langmuir Hinshelwood mechanism, including CO, C3H8, and water is implemented into 1-D and 3-D Catalytic Converter models. The CH4 kinetic model is calibrated with the experiment by using synthetic exhaust gas generator.
2017-10-08
Technical Paper
2017-01-2237
K. Gopal Duleep
The overall objectives of this study are to establish the relationship between a spark ignition, or Otto cycle, engine energy efficiency and the octane number of the fuel through a comprehensive review of recently published literature. The efficiency of the ideal Otto cycle is a function of the compression ratio, but increasing compression ratio is limited by the onset of knock, which can be prevented by increasing fuel octane number. Hence, in an ideal case, there is a direct connection between engine efficiency and fuel octane number. In the real world, other factors also contribute to the relationship and spark timing is the primary control variable that affects both knock and efficiency. This analysis explores the relationship between efficiency and octane number.
2017-10-08
Technical Paper
2017-01-2242
Boyuan Wang, Zhi Wang, Changpeng Liu, Fubai Li, Yingdi Wang, Yunliang Qi, Xin He, Jianxin Wang
A new ignition method is proposed called flame accelerated ignition, which is realized by a flame acceleration tunnel set between the spark plug and the main chamber with annular spoilers inside. The investigation of flame accelerated ignition was experimentally accomplished on both a rapid compression machine with optical accessibility and a single-cylinder heavy duty engine. In rapid compression machine study, synchronous pressure sensing and high-speed photography were used with spark ignition cases tested for comparison. The results show that the combustion process is significantly accelerated by flame acceleration ignition. The combustion duration is shortened by more than 30% under all loads compared with spark ignition. According to the optical results, the axial speed of flame outside the flame acceleration tunnel reaches at least 30 m/s and shows positive correlation with load, which is over 10 times than that of conventional flame propagation caused by spark ignition.
2017-10-08
Technical Paper
2017-01-2229
Byeongsoek Lee, Heechang Oh, SeungKook Han, SooHyung Woo, JinWook Son
There are two way to improve engine thermal efficiency. One is to improve the theoretical thermal efficiency by increasing the compression ratio and specific heat ratio. The other is to reduce various engine losses like friction, pumping, heat loss. For the development of Ultra High Efficiency, We designed the new 2.0L NA GDI engine based on HMC's Nu 2.0L GDI engine. We conducted various parameter studies related to gasoline combustion characteristic, such as compression ratio, ignition system, intake port design, cam duration, Cooled EGR, etc. As a result, we achieved the maximum thermal efficiency up to 42%(~200g/kWh) in stoichiometric AFR. This paper described the ways and possibilities to improve the maximum thermal efficiency.
2017-10-08
Technical Paper
2017-01-2249
Chen Wang, Tianyou Wang, Kai Sun, Zhen Lu, Yong Gui
Clean combustion is critical for marine engines to meet the Tier III emission regulation. In this paper, the effects of EGR and injection strategies (including injection pressure, injection timing as well as multiple injection technology) on the performance and emissions of a 2-stroke, low speed marine diesel engine were investigated by using computational fluid dynamics (CFD) simulations to reach the IMO Tier III NOx emissions target and reduce the fuel consumption rate. Due to the large length scale of the marine engine, RANS simulation was performed in combination with the CTC-SHELL combustion model. Based on the simulation model, the variation of the cylinder pressure curve, the average temperature in the cylinder, the combustion heat release rule and the emission characteristics were studied.
2017-10-08
Technical Paper
2017-01-2398
Bei Liu, Xiaobei Cheng, Jialu Liu, Han Pu, Li Yi
Based on a 4 cylinder turbocharged diesel engine, the research aims at studying the influence of some the fuel injection timing, fuel injection pressure and the ratio of pilot injection fuel to the engine combustion and emission formation under the condition of single injection and pilot injection ,respectively ,which the main focus on the emission characteristics of particles .The results show that the early-injection PPC formed by single injection can reduce the quantity and quality and GMD of particles obviously. However, when the injection timing is too early, the quantity of particles will rise as normal mode. The effect of injection pressure on particles is significant. The quantity of particles will increase under the condition of PPC, but the quality and GMD of particles is first decrease and the increase. The curve of size distribution of particles displays three peaks shape.
2017-10-08
Technical Paper
2017-01-2409
Erbao Zhang, Yinchun Gong, Jun Deng, Zongjie Hu, Chuanqian Jiang, Zhijun Wu, Liguang Li
Hydrogen fuel will be a potential energy source for internal combustion engines in the future. A promising approach for improving the efficiency and achieving zero-emission is to employ the noble gas argon. The work of this paper aimed at investigating the cyclic variation of argon power cycle engine with fuel of hydrogen. The engine has been modified based on a 0.4 L, one signal cylinder diesel engine into spark ignition engine with a port fuel injection system. The influencing factors on the cyclic variation in the argon power cycle engine with fuel of hydrogen, such as type of working gas, ignition timing, compression ratio (5.6, 6.9, and 7.35), and CO2 fraction in the mixture of argon and oxygen, were test in this study. The results show that compared to air, higher indicated mean effective pressure (IMEP) and better engine operation stability could be achieved under an atmosphere of argon and oxygen.
2017-10-08
Technical Paper
2017-01-2354
Dave Horstman, John Sparrow
Due to recent legislation on CO2 emissions, Heavy Duty OEM’s and their suppliers have had an increased interest in improving vehicle fuel economy. Many aspects are being investigated including vehicle aerodynamics, tire rolling resistance, waste heat recovery, engine fuel efficiency, and many others. Crankcase lubricants offer a cost-effective mechanism to reduce engine friction and increase engine fuel efficiency. The potential gains realized by optimized fuel-efficient lubricants are relatively small, on the order of 1-3%. Therefore, in order to develop these lubricants, formulators must have a robust, repeatable, and realistic test method for differentiation. To address this need, Intertek has been involved with developing fuel economy tests for many years, starting with what became the Sequence VI test for passenger car lubricants in the early 1990’s. Most recently, Intertek has helped develop different FE programs to support the MD and HD diesel industry.
2017-10-08
Technical Paper
2017-01-2358
Michael P Gahagan
The automotive transmission market has seen an increase in the number of hybrid electric vehicles (HEV), and forecasts predict additional growth. In HEVs, the hybrid drivetrain hardware can combine electric motor, clutches, gearbox, electro-hydraulics and the control unit. In HEV hardware the transmission fluid can be designed to be in contact with an integrated electric motor. One transmission type well-suited to such hybridization is the increasingly utilized dual clutch transmission (DCT), where a lubricating fluid is in contact with the complete motor assembly as well as the DCT driveline architecture. This includes its electrics, and therefore raises questions around the suitability of standard transmission fluids in such an application. This therefore drives the need for further understanding of fluid electrical properties in addition to the more usually studied engineering hardware electrical properties.
2017-10-08
Technical Paper
2017-01-2442
Bingqing Xiao, Wei Wu, Jibin Hu, Shihua Yuan, Chenhui Hu
The prediction of temperature distribution and variation of oil-cooled sliding disk pair is essential for the design of wet clutches and brakes in vehicle transmission system. A heat transfer model is established in the study and some fluid-solid coupled heat transfer simulations are performed to investigate the thermal behaviors of wet clutch during sliding. Both cooling liquid and grooved solid disks are contained in the heat transfer model and the heat convection due to the cooling liquid in the radial grooves is also considered by fluid-solid coupled transient heat transfer simulations. The temperature distribution and variation of the grooved disk are discussed and analyzed in detail. The results indicate that the temperature distribution on the grooved disk is nonuniform. The temperature within the middle radius area is higher than that in the inner and outer radius area. The outer radius temperature is higher than the inner radius temperature at the contact face.
2017-10-08
Technical Paper
2017-01-2462
Ruipeng Zhang, Kaichuang Meng
The powertrain of the separated axle hybrid electric dump truck was analyzed, and the vehicle dynamics model was established. Considering the switch among different drive modes during the process of driving, a driving force coordinated allocation control strategy was applied. The control strategy adopts hierarchical structure, the upper layer determines power take-off mode of the vehicle, the middle layer calculates the drive torque of each axle according to its axle load, the lower layer uses PID algorithm to avoid the slip of the drive axle. Control model is established according to the control strategy, combined with the established vehicle dynamic model, co-simulation was conducted. The simulation results show that the driving force coordinated control strategy can adapt to the full load climbing condition and low adhesion road condition, realize the reasonable distribution of driving force and make full use of the ground adhesion.
2017-10-08
Technical Paper
2017-01-2383
Guoyang Wang, Jun Zhang, Bo Yang, Chuandong Li, Shi-Jin Shuai, Shi Yin, Meng Jian
Urea selective catalytic reduction (SCR) is a key technology for heavy-duty diesel engines to meet the increasingly stringent nitric oxides (NOx) emission limits of regulations. The urea water solution injection control is critical for urea SCR systems to achieve high NOx conversion efficiency while keeping the ammonia (NH3) slip at a required level. In general, an open loop control strategy is sufficient for SCR systems to satisfy Euro IV and Euro V NOx emission limits. However, for Euro VI emission regulation, advanced control strategy is essential for SCR systems due to its more tightened NOx emission limit and more severe test procedure compared to Euro IV and Euro V. This work proposed an approach to achieve model based closed loop control for SCR systems to meet the Euro VI NOx emission limits. A chemical kinetic model of the SCR catalyst was established and validated to estimate the ammonia storage in the SCR catalyst.
2017-10-08
Technical Paper
2017-01-2201
Zhongye Cao, Tianyou Wang, Kai Sun, Lei Cui, Yong Gui
For uniflow scavenged two-stroke marine diesel engines, the main function of scavenging process is to replace the burned gas with fresh charge. The end state of scavenging process is integral to the subsequent compression and combustion, thereby affecting the engine’s fuel economy, power output and emissions. In this paper, a complete working cycle of a large marine diesel engine was simulated by using the 3D-CFD software CONVERGE. The model was validated by mesh sensitivity test and experiment data. Based on this calibrated model, the influences of swirl ratio and exhaust valve closing (EVC) timing on the scavenging process were investigated. The parameters evaluating the performance of scavenging process were introduced. The results show that, by adjusting the swirl orientation angle(SOA) from SOA=10° to SOA=30°, different swirl ratios are generated and have obvious differences in flow characteristics and scavenging performance.
Viewing 1 to 30 of 57666

Filter