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2017-11-16
Journal Article
2017-01-9286
David Oh, Martin Brouillette, Jean-Sebastien Plante
A vortex-stratified combustion process for hydrogen-fueled reciprocating internal combustion engines is introduced to increase the thermal efficiency by reducing the convective heat transfer losses to the surrounding walls during combustion. The process imposes a highly ordered rotational field upon the charge in a separate, transverse, cylindrically shaped combustion chamber by means of channels that connect with the main chamber enclosed by the engine cylinder and piston. Gaseous hydrogen is injected directly during the compression stroke, while air enters into the combustion chamber tangentially and preferentially along the circumference due to the Coandă effect. The two streams entrain one another and develop into a vigorous vortex by virtue of the chamber and channel geometries.
2017-11-16
Journal Article
2017-01-9284
Sayan Biswas, Li Qiao
Gas engines often utilize a small-volume pre-chamber in which fuel is injected at near stoichiometric condition to produce a hot turbulent jet which then ignites the lean mixture in the main chamber. Hot jet ignition has several advantages over traditional spark ignition, e.g., more reliable ignition of extra-lean mixtures and more surface area for ignition resulting in faster burning and improved combustion efficiency. Our previous experimental results show that supersonic jets could extend the lean flammability limit of fuel/air mixtures in the main chamber in comparison to subsonic jets. The present paper investigated the characteristics of supersonic hot jets generated by combustion of stoichiometric H2/air in a pre-chamber to understand the ignition mechanism of ultra-lean mixtures by supersonic hot jets.
2017-11-16
Journal Article
2017-01-9287
David Oh, Martin Brouillette, Jean-Sebastien Plante
In this second of two parts, the fundamentals of convective wall heat transfer losses are elucidated in the context of the desired objective toward its reduction in a direct-injected, hydrogen-fueled internal combustion engine. A comparative, transient 2D CFD analysis evaluated at 4500 RPM between a combustion chamber design representing current practice and the here-introduced “vortex-stratified combustion” process finds an approximately 50% reduction in the convective flux with the latter. The simulation results show that reduced heat flux of the vortex approach is driven by the combination of two effects.
2017-11-16
Journal Article
2017-01-9288
Stefania Falfari, Gian Marco Bianchi, Giacomo Micci, Augusto Della Torre, Gianluca Montenegro, Angelo Onorati, Sergio Negro
Metallic open-cell foams have proven a good attitude for many engineering fields. Their success is mainly related to mechanical strength, low density, high specific surface, good thermal exchange, low flow resistance and sound absorption properties. The present work aims to investigate three principal aspects of real foams: the geometrical characterization, the flow regime characterization, the effects of the pore size and the porosity on the pressure drop. The first aspect is very important, since the geometrical properties depend on other parameters, such as porosity, cell/pore size and specific surface. A statistical evaluation of the cell size of a foam sample is necessary to define both its geometrical characteristics and the flow pattern at a given input velocity. To this purpose, a procedure which statistically computes the number of cells and pores with a given size has been implemented in order to obtain the diameter distribution.
2017-10-31
White Paper
WP-0002
The environmental impact of hydrocarbon-burning aircraft, both from the perspective of gas emissions and that of noise, is one of the main motivations for the move to electric propulsion. The added benefit from this shift to electric propulsion is that it has resulted in lowering the costs of electrical components such as motors, power electronic (PE) circuits, and batteries that are essential to this technology. This white paper seeks to explore the history, architecture, electrical components, and future trends of electric flight technology.
2017-10-16
Technical Paper
2017-01-7007
Hardik Lakhlani, Himanshu Gupta
Turbocharging has become an important method for increasing the power output of diesel engines. A perfectly matched turbocharger can increase the engine efficiency and decrease the BSFC. For turbocharger matching, engine manufacturers are dependent on the turbocharger manufacturers. In this paper, an analytical model is presented which could help engine manufacturers to analyze the performance of turbocharger for different load and ambient condition using compressor and turbine map provided by turbo manufacturers. The analytical model calculates the required pressure at inlet and exhaust manifold for fixed vane turbocharger with waste gate using inputs like BSFC, lambda, volumetric efficiency, turbocharger efficiency and heat loss, that are available with the engine manufacturer.
2017-10-13
Technical Paper
2017-01-7005
Lijuan Wang, Jeffrey Gonder, Eric Wood, Adam Ragatz
Fuel consumption (FC) has always been an important factor in vehicle cost. With the advent of electronically controlled engines, the controller area network (CAN) broadcasts information about engine and vehicle performance, including fuel use. However, the accuracy of the FC estimates is uncertain. In this study, the researchers first compared CAN-broadcasted FC against physically measured fuel use for three different types of trucks, which revealed the inaccuracies of CAN-broadcast fueling estimates. To match precise gravimetric fuel-scale measurement, polynomial models were developed to correct the CAN-broadcasted FC.Lastly, the robustness testing of the correction models was performed. The training cycles in this section included a variety of drive characteristics, such as high speed, acceleration, idling, and deceleration. The mean relative differences were reduced noticeably.
2017-10-13
Technical Paper
2017-01-5012
Harveer Singh Pali, Shashi Prakash Dwivedi
In the present work, A356/SiC metal matrix composite with different weight percent of SiC particles were fabricated by two different techniques such as mechanical stir-casting and electromagnetic stir casting. The wear and frictional properties of the metal matrix composites were studied by performing dry sliding wear test using a pin-on-disc wear tester for both electromagnetic stir casting samples and mechanical stir casting samples. The wear rate increases with the addition of normal force, while decreases by increasing the percentage of reinforcement. Frictional coefficient increases by increasing the normal force and percentage of reinforcement. Increasing percentage of reinforcement and using electromagnetic stir casting process obtained the higher frictional coefficient and lower wear rate.
2017-10-13
Technical Paper
2017-01-5013
G. Magendran
The input shafts are conventionally developed through Hot forging route. Considering upcoming new technologies the same part was developed through cold forging route which resulting in better Mechanical properties than existing hot forging process. It has added benefit of cost as well as environmental friendly. Generally the part like Input shaft which having gear teeth, splines etc., will be manufactured through Hot forging process due to degree of deformation, availability of press capacity, diameter variations etc., This process consumes more energy in terms of electricity for heating the bar and also creates pollution to the atmosphere. Automotive input shaft design modified to accommodate cold forging process route to develop the shaft with press capacity of 2500T which gives considerable benefit in terms of mechanical and metallurgical Properties, close dimensional tolerances, less machining time, higher material yield when compared to hot forging and metal cutting operation.
2017-10-13
Technical Paper
2017-01-5015
Samuel Joseph Reinsel, Douglas Nelson
The purpose of this research is to refine the shifting behavior and drivability of a post transmission (P3) plug-in parallel hybrid electric vehicle (PHEV) being developed by the Hybrid Electric Vehicle Team (HEVT) for the EcoCAR3 competition. The vehicle’s powertrain has been modified with an electric motor placed on the driveshaft after the conventional 8 speed automatic transmission. This motor can be leveraged to smooth out the jerk experienced by the driver during part-load transmission shifts, as well as other drivability metrics such as gearshifts and cruise control. These metrics also include powered take off, tip in, and tip out events. Additionally, improving the drivability of active fuel management (AFM or cylinder deactivation) mode by assisting the engine will be examined to attempt to improve drivability.
2017-10-13
Technical Paper
2017-01-5014
Maurilio Pereira Gomes, Igor Santos, Camila Couto, Cristiano Mucsi, Jesualdo Luiz Rossi, Marco Colosio
This work consists of evaluating the influence of heat treatment of sintered valve seat insert (VSI) manufactured with three different high-speed steels: AISI M3:2, AISI M2 and AISI D2. The high-speed powders were mixed with iron powders and additives such as manganese sulphide, zinc stearate, graphite and carbides. All the used powders had the particle size distribution and morphological aspects analyzed. The heat treatment of the VSI’s consisted of air quenching followed by double tempering in seven different equidistant temperatures (from 100 ºC until 700 ºC). A data acquisition system using thermocouple type K was used to determine the quenching process and mainly the cooling ratio. The physical properties were carried out through the measurement of the VSI’s bulk density and hardness. The metallurgical evaluation consisted of etching the VSI’s and then analyzing it with optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).
2017-10-13
Technical Paper
2017-01-5016
A. Tyagi, N. Madhwesh
With the advancements of trends in Formula1 it has been quite clear that aerodynamics plays one of the most vital roles in the performance of the car. A typical aerodynamic package of a Formula1 car consists of rear wings, front wings and an under tray diffuser. This research paper is concerned with the development of an efficient under tray diffuser. The under tray diffuser is a shaped section of the car underbody to improve the aerodynamic properties of the car. Mainly it is used to generate maximum down force corresponding to minimum drag. Several studies have been carried out in recent decades to improve the vehicle performance, aerodynamic properties in particular. The present work also deals with the improvement of the aerodynamic performance of the vehicle by varying the geometric properties of the under tray diffuser such as Inlet angle, Outlet angle corresponding to varying ground clearances.
2017-10-13
Technical Paper
2017-01-5017
Ronith Stanly, Gopakumar Parameswaran, R Rajkiran
Conventionally, influence of injector coking deposits has been studied using accelerated coking methodology. For this work however, in-use vehicles with Common Rail Direct injection (CRDi) injectors were sourced in “as-is where is” condition with considerable coked injector deposits. They were then cleaned with a commercial fuel system cleaning solution and the influence of the deposits on vehicular performance and spray field were studied. It was observed that the removal of coking deposits resulted in an increase in the Brake Horse Power (BHP) of the vehicle, a lower fuel injected quantity and lower fuel injection duration. It was also observed that the removal of deposits resulted in better atomization of fuel spray, better uniformity of the multiple spray jets and an increase in the flow rate of the test injectors.
2017-10-13
Technical Paper
2017-01-5018
Subhash Hanmant Bhosale, Manohar Goud Kalal, Ashish Kumar Sahu
In today’s cost-competitive automotive market, use of finite element simulations and optimization tools has become crucial to deliver durable and reliable product. Simulation driven design is the key to deliver lightweight products in shortest time possible. In the early phase of new product development, identifying structural load paths is necessary. As design matures, front loading through use of topology, topography and gauge optimization tools is a must to deliver the optimal lightweight structure. Structural optimization applied to component design is a real way to reduce number of physical prototypes, design iterations, costs and time to market. However, simulation driven design optimization tools have struggled to find global acceptance and are typically underutilized in many applications; especially in situations where the algorithms have to compete with existing know-how decision making processes.
2017-10-13
Technical Paper
2017-01-7006
Gao Ke, Zhao Weiqiang, Xiaojian Han
As the main passenger and freight transport equipment,commercial vehicle’s safety and comfort has become particularly important.Due to the long traveled distance,commercial vehicle is equipped with more than one driver.Different drivers have their unique steering behavior and same driver have a large physical power change when driving for a long time.Therefore,the needs of drivers cannot be met by a single model of the steering characteristics.If the vehicle steering characteristics are not suitable for the drivers,the vehicle will always produce too much/ little of the steering angle when driver controls steering system.The steering angle need to be adjusted again by driver when this happens.The occurrence of such a situation will affect the road safety, and cause extra burden on driver. On the basis of the traditional hydraulic power, dynamic steering system adds an electric servo motor to the steering column.
2017-10-08
Technical Paper
2017-01-2294
Julien Gueit, Jerome Obiols
Abstract In order to be ever more fuel efficient the use of Direct Injection (DI) is becoming standard in spark ignition engines. When associated with efficient turbochargers it has generated a significant increase in the overall performance of these engines. These hardware developments lead to increased stresses placed upon the fuel and the fuel injection system: for example injection pressures increased up to 400 bar, increased fuel and nozzle temperatures and contact with the flame in the combustion chamber. DISI injectors are thus subjected to undesirable deposit formation which can have detrimental consequences on engine operation such as reduced power, EOBD (Engine On Board Diagnostics) issues, impaired driveability and increased particulate emissions. In order to evaluate the sensitivity of DI spark ignition engines to fuel-related injector deposit formation, a new engine test procedure has been developed.
2017-10-08
Technical Paper
2017-01-2301
Hongli Gao, Fujun Zhang, Wenwen Zeng, Tianpu Dong, Zhengkai Wang
Abstract The electronic control of direct injection fuel system, which could improve engine fuel efficiency, dynamics and engine emission performance through good atomization, precise control of fuel injection time and improvement of fuel-gas mixture, is the key technology to achieve the stratified combustion and lean combustion. In this paper, a direct injection injector that based on voice coil motor was designed aiming at the technical characteristics of one 800cc two-stroke cam-less engine. Prior to a one - dimensional simulation model of injector was established by AMEsim and the maximal fuel injection demand was met via the optimization of the main parameters of the injector, the structure of the voice coil motor was optimized by magnetic equivalent circuit method. After that, the maximal flow rate of the injector was verified by the injector bench test while the atomization characteristic of the injector was verified by using a high-speed camera.
2017-10-08
Technical Paper
2017-01-2303
Yan Wang, Xudong Wang, Zhen Zhang, Yong Wang, Guoxiu Li, Yusong Yu
Abstract Fuel spray impingement is a common phenomenon during the combustion processes of a DI diesel engine. When liquid droplets impinge on the hot surface of a combustion chamber, a complex heat transfer and mechanical interaction occur between the droplets and combustion chamber. This probably changes the surface topography and microstructure of the impact position. Based on the experimental method, the fuel spray phenomenon and conditions of a surface pit caused by droplet impingement were investigated. The experimental results indicate that the surface pit is formed under specific conditions, i.e., a specific droplet diameter and surface temperature. Scanning electron microscopy of the pit area shows that the microstructure of the pit changed from an original dense and smooth surface to a loose structure. The microstructure of the pit did not show a molten state. The concentration of metal and nonmetallic elements in the pit area changed significantly.
2017-10-08
Technical Paper
2017-01-2304
Hui Ding, Frank Husmeier, Jayesh Gudekar, Amol Bobade, Deepak Patil
Abstract This paper discusses the holistic approach of simulating a low pressure pump (LPP) including test stand flow dynamics. The simulation includes all lines and valves of the test stand representing realistic test operating conditions in the simulation. The capability to capture all line dynamics enables a robust design against resonances and delivers high-quality performance data. Comparison with actual test data agrees very well giving us confidence in the prediction capability of proposed method and CFD package used in the study. Despite the large spatial extent of the simulation domain, Simerics-MP+ (aka PumpLinx) is able to generate a feasible mesh, together with fast running speed, resulting in acceptable turn-around times. The ability to still model small gaps and clearance of the LPP very efficiently enables inclusion of realistic tolerances as experienced on hardware.
2017-10-08
Technical Paper
2017-01-2283
Anand Prabu Kalaivanan, Gnanasekaran Sakthivel
Abstract Electronic Fuel Injection Systems have revolutionised Fuel Delivery and Ignition timing in the past two decades and have reduced the Fuel Consumption and Exhaust Emissions, ultimately enhancing the Economy and Ecological awareness of the engines. But the ignition/injection timing that commands the combustion is mapped to a fixed predefined table which is best suited during the stock test conditions. However continuous real time adjustments by monitoring the combustion characteristics prove to be highly efficient and be immune to varying fuel quality, lack of transient performance and wear related compression losses. For developing countries, Automotive Manufacturers have been Tuning the Ignition/Injection timing Map assuming the worst possible fuel quality. Conventional knock control system focus on engine protection only and doesn't contribute much in improving thermal efficiency.
2017-10-08
Technical Paper
2017-01-2284
Haifei Zheng
Abstract The potential benefits of reheat burner placed between turbine stages for propulsion system have been recognized for nearly a century. Compared to the conventional non-reheat engines, the turbine inter-guide-vane burner (TIB) engines by using jet-swirl flow scheme (high-G loading) are shown to have a higher specific thrust with no or only small increase in thrust specific fuel consumption. But, it is a known fact that the G loading in the circumferential cavity is inversely proportional to the radius of the circumferential cavity. If one needs to scale this configuration for a larger spool of turbine components, the effeciency of the high G operation and obtained benefits on flame speed will reduce and hence the performance will de-grade.
2017-10-08
Technical Paper
2017-01-2286
A S Ramadhas, Punit Kumar Singh, Reji Mathai, Ajay Kumar Sehgal
Abstract 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 engine 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
2017-01-2288
Tianyuan Zhou, Changsheng Yao, Fuyuan Yang, Sun Jinwei
Abstract Low temperature combustion (LTC) is an advanced combustion mode, which can achieve low emissions of NOx and PM simultaneously, and keep relatively high thermal efficiency at the same time. However, one of the major challenges for LTC is the cold condition. In cold conditions, stable compression ignition is hard to realize, while thermal efficiency and emissions deteriorate, especially for gasoline or fuel with high octane number. This study presents using pressure sensor glow plugs (PSG) to realize Glow plug assisted compression ignition (GA-CI) at cold conditions. Further, a glow plug control unit (GPCU) is developed, a closed-loop power feedback control algorithm is introduced based on GPCU. In the experiment, engine coolant temperature is swept. Experimental results show that GA-CI has earlier combustion phases, larger combustion duration and higher in-cylinder pressure. And misfire is avoided, cycle-to-cycle variations are greatly reduced.
2017-10-08
Technical Paper
2017-01-2289
Chunze Cen, Han Wu, Chia-Fon Lee, Shuxin Hao, Fushui Liu, Yikai Li
Abstract Droplets impacting onto the heated surface is a typical phenomenon either in CI engines or in GDI SI engines, which is regarded significant for their air-fuel mixing. Meanwhile, alcohols including ethanol and butanol, has been widely studied as internal combustion engine alternative fuels due to their excellent properties. In this paper, under different component ratio conditions, the ethanol-butanol droplet impacting onto the heated aluminum surface has been studied experimentally. The falling height of the droplets were set at 5cm. A high-speed camera, set at 512×512pixels, 5000 fps and 20 μs of exposure time, was used to visualize the droplet behavior impinging onto the hot aluminum surface. The impact regimes of the binary droplet were identified. The result showed that the Leidenfrost temperature of droplets was affected by the ratio of ethanol to butanol. The higher the content of butanol in the droplet, the higher the Leidenfrost temperature.
2017-10-08
Technical Paper
2017-01-2309
Hua Wen, Shuaishuai Liang, Peng Chen, Guangjun Jiang
Abstract In this paper, a contrast experiment has been carried out for discussing the phenomenon of fuel dripping at the end of injection by using the different nozzles with varied materials. The experiment results show that the nozzle deformation has an important effect on the fuel dripping at the end of injection. The duration of the fuel shut-off process with the steel nozzle which producing smaller deformation is shorter than the polymethyl methacrylate nozzle. The mass of fuel dripping with the steel nozzle is less. For implementing a deep analysis on the experimental phenomenon about the fuel dripping with the polymethyl methacrylate nozzle, a three dimensional numerical simulation research was carried out for analyzing the influence of fuel flow inside nozzle on the solid deformation and stress distribution of the nozzle by using Fluid-Structure-Interaction method.
2017-10-08
Technical Paper
2017-01-2323
Lei Li, Kai Sun, Jianyu Duan
Abstract Butanol is a promising alcohol fuel. Previous studies on combustion and diesel engines showed different trends in sooting tendencies of the butanol isomers (n-butanol, iso-butanol, sec-butanol and tert-butanol).The impact of butanol isomers on the particulate emissions of GDI (Gasoline Direct Injection) engines, however, has not been reported. This work examines the combustion performance and particle number emissions of a GDI engine fueled with gasoline/butanol blends in steady state modes. Each isomer was tested at blend ratios from 10% to 50% by volume. Spark timings for all the fuels are set to obtain the maximum break torque (MBT), i.e. the MBT spark timings. Results show that the particle number concentration is reduced significantly with increasing butanol content for all the isomers.
2017-10-08
Technical Paper
2017-01-2282
Gen Chen, Wenxin Cai, Jianguang Zhou, Christian Spanner, Heribert Fuchs, Werner Schrei, Karl Weihrauch
Abstract A TGDI (turbocharged gasoline direct injection) engine is developed to realize both excellent fuel economy and high dynamic performance to guarantee fun-to-drive. In order to achieve this target, it is of great importance to develop a superior combustion system for the target engine. In this study, CFD simulation analysis, steady flow test and transparent engine test investigation are extensively conducted to ensure efficient and effective design. One dimensional thermodynamic simulation is firstly conducted to optimize controlling parameters for each representative engine operating condition, and the results serve as the input and boundary condition for the subsequent Three-dimensional CFD simulation. 3D CFD simulation is carried out to guide intake port design, which is then measured and verified on steady flow test bench.
2017-10-08
Technical Paper
2017-01-2290
Zhixin Sun, Shaoqing Yang, Xinyong Qiao, Zhiyuan Zhang
Abstract When operating at high elevation of 3700m (atmospheric pressure about 68 kPa), the combustion process of diesel engine deteriorates, and the engine performance declines significantly. In this paper, Isooctyl Nitrate(EHN) is blended into the diesel fuel as additive to improve the combustion process. The decomposition of Isooctyl Nitrate(EHN) is analyzed and its mechanism is studied through chemical kinetics. A series of tests were carried out on a single cylinder diesel engine to study the effects of EHN on diesel engine combustion with the low intake pressure of 68kPa. Results show that the generation of OH、 H、 HO2 and H2O2 in n-heptane cleavage reactions can be promoted by EHN. In both stages of low and high temperature, the decomposition of n-heptane is accelerated, which shortened the ignition delay period. Four kinds of fuel are studied by tests: diesel fuel, diesel fuel with 0.3%, 0.6% and 0.9% mass fraction EHN respectively.
2017-10-08
Technical Paper
2017-01-2305
Jun Yamauchi, PengBo Dong, Keiya Nishida, Youichi Ogata
Abstract The performance of a diesel engine largely depends on the spray behavior and mixture formation. Nozzle configurations and operating conditions are important factors that influence spray development. Using numerical and experimental methods, this study focused on the spray development of multi-hole nozzles under non-evaporating and evaporating conditions to compare the influence of nozzle hole diameter and injection pressure on spray characteristics. High-speed video observation was employed to study the properties of spray development under the non-evaporating condition, while the Laser Absorption Scattering technique was used in the observation and quantitative analysis of evaporating spray characteristics in the evaporating condition. In addition, computational fluid dynamics study results published previously [1] were correlated with the current experimental results to provide more detailed explanations about the mechanism of the characteristics of spray behavior.
2017-10-08
Technical Paper
2017-01-2306
Xiaochuan Sun, Xiang Li, Zhong Huang, Dehao Ju, Xing-cai Lu, Dong Han, Zhen Huang
Abstract Recently, the shortage of fossil resources contributes to strict regulations of environmental protection. The research on the high efficiency and low emission of engines becomes an important direction all over the world. Technologies like high injection pressure, high levels of supercharging and higher levels of back pressure have come into application. Increasing the injection pressure and average cylinder pressure results in that parts of the spray can experience transcritical and supercritical regimes. In this paper, we established a surrogate fuel composed of n-Hexadecane, HMN and 1-Metylnaphthalene, to analyze the injection and atomization of diesel surrogate fuel with large eddy simulation (LES) in a cubic calculation region with high temperature and high pressure environment.
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