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Viewing 1 to 30 of 110610
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.
2017-11-16
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.
2017-10-31
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.
2017-10-13
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
2017-01-2219
Xihui Wang
Conventional heat transfer fluids used for cooling fluids in vehicle cooling water jacket have relatively poor heat transfer performance.One method for enhance heat transfer in cooling-jacket uses nanofluids. Nanofluids have heat transfer enhancement merits .In the present study, the numerical simulation on Fe3O4 nanofluid flow in cooling water jacket of Gasline direct injection engine wax performed using computational fluid dynamics ( CFD) software FLUENT. The heat transfer coefficient of nanofluids was calculated and verified by experiment. Fe3O4 nano-particles were used in mixture of water/ethylene glycol as a base fluid. The thermal performance of the nanofluid was studied, also the thermal performance of a cooling-jacket was studied with CFD software. The simulation was performed for different volumetric concentrations of(1%,2%,5%) nanofluids of different engine speeds.
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
2017-01-2460
Wenbin Liu, Qiang Song, Yiting Li, Wanbang Zhao
In this paper, a novel driver model is proposed to track vehicle speed in MIL (Model-in-the-Loop) test system, which has structural consistency with HIL (Hardware-in-the-Loop) test system. First, the MIL test system which contains models of driver, vehicle and test bench is established. Second, according to the connections of the established models in Matlab/Simulink environment, the vehicle speed is calculated in vehicle model. Emphatically, through the deviation between driving cycle speed and calculated vehicle speed, PI controller in driver model adjusts the vehicle speed to ideal point through sending the torque command to drive motor, the ILC (Iterative Learning Control) controller modifies and stores P value of PI controller. Then, in order to obtain the better modification of PI controller, iterative learning control algorithm is deeply researched in term of types and parameters.
2017-10-08
Technical Paper
2017-01-2450
Chao Xu, Fuyuan Yang, Jinyu Zhang
Power-split is highlighted as the most popular concept for full hybrid electric vehicles (HEV). However, the energy management and design of power-split heavy duty truck under Chinese driving conditions still need to be investigated. In this paper, the parametric design and an equivalent consumption minimization strategy (ECMS) for the power-split heavy duty truck are presented. Besides, the influence of a penalty factor also discussed. Meanwhile, two different methods to search the engine operation point has been proposed. And the simulation shows both fuel consumption can satisfy the second phase fuel consumption standard and the third phase fuel consumption standard which will be implemented in 2020, in the C-WTVC (Chinese-World Transient Vehicle Cycle). Based on ECMS a design for generator motor and traction motor in power-split heavy duty truck has been processed. The fuel consumption has been indicted to decrease, with the motor power increasing.
2017-10-08
Technical Paper
2017-01-2457
Rickard Arvidsson, Tomas McKelvey
A two-state forward dynamic programming algorithm is evaluated in a series hybrid drive-train application with the objective to minimize fuel consumption when look-ahead information is available. The states in the new method are battery state-of-charge and engine speed. The new method is compared to one-state dynamic programming optimization methods where the requested generator power is found such that the fuel consumption is minimized and engine speed is given by the optimum power-speed efficiency line. The other method compared is to run the engine at a given operating point where the system efficiency is highest, finding the combination of engine run requests over the drive-cycle that minimizes the fuel consumption. The work has included the engine torque and generator power as control signals and is evaluated in a full vehicle-simulation model based on the Volvo Car Corporation VSIM tool.
2017-10-08
Technical Paper
2017-01-2454
Yiqi Jia, Gangfeng Tan, Cenyi Liu, Shengguang Xiong, Zehao Yang, Xingmang Zheng
In these years, the advantages of using phase change material in the thermal management of electric power battery has been wide spread. Because of the thermal conductivity of most phase change material (eg.wax) is low, many researchers choose to add high conductivity materials(such as black lead). However, the solid-liquid change material has large mass, poor flowability and corrosivity. Therefore, it still stays on experiential stage. In this paper, we use pure water as liquid phase change material (PCM), adopts PCM with an reflux device for thermal management. Meanwhile, utilizing the characteristics of pure water which are economical, easy to prepare, light weight, strong liquidity and hardly corrode the battery to explore the feasibility for water as a PCM for battery thermal management system. We use CATIA to build battery model and FloEFD to simulate temperature distribution of battery during its working stage.
2017-10-08
Technical Paper
2017-01-2456
Yun Li, Jing Shang, Shiwu Zhu, Alina Ma, Robin Lyle, Zijian Li, Nannan Wang, Hua Rong
This paper presents an Integrated Power Module (IPM) and an Integrated Power Unit (IPU) which are based on the IGBT double sided cooling technology. The IPU can be used as the motor control inverter in the electric vehicle. And the IPM used in the IPU is packaged with latest 650V/600A trench field-stop IGBT device and double sided bonding and cooling technology. With the double sided bonding, planar bonding is realized which eliminates the traditional wire bonds. Powers cycling capability and long time reliability of the module have been greatly improved. Integrating with the double sided cooling, a large thermal exchanging area of the dies is achieved. Compared with the traditional single sided cooling module, thermal resistance has been reduced by 23% according to the test. Equipped with the active gate driver technology which utilizing the di/dt control and decoupling of turn-on and turn-off processes, power losses of the IPM have been greatly reduced and optimized.
2017-10-08
Technical Paper
2017-01-2452
Kingsley Joel Berry, Abdrahamane Traore, Aravind Krishna, Pavankumar Gangadhar, Allan Taylor
This paper documents the electrical infrastructure design of a Hybrid Go Kart competition vehicle which includes a dual Fuel Cell power system, Ultra Capacitors for energy storage, and a dual AC induction motor capable of independent drive. The Kart was built primarily to compete in the 2009 Formula Zero international event. The vehicle model was developed in Simulink to determine whether the fuel cell and ultra-capacitor combination will be sufficient for peak transient power requirement of 36 kW. The vehicle’s functional description and performance specifications are documented including the integration of the fuel cell power modules, energy storage system, power converters, and AC motor and motor controllers.
2017-10-08
Technical Paper
2017-01-2453
Shuang Liu, Lina Pan, Xin Jiang, Yujiao Wang, Kun Liu, Yang Xia
Quick drop battery system was the core components of the electric vehicles, the reliability and compatibility of quick drop battery system was directly related to the popularization and application of electric vehicles. In this article, a split type battery management system and a split type high voltage architecture is used to achieve better charging compatibility. Meanwhile the number of fast switching connector’s pin is reduced and the plug life is prolonged to more than 10000 times by using floating structure. For battery management system (BMS), the state of charge (SOC) estimation was based on dynamic voltage correction, and make estimation accuracy reach to less than 5%. Rotary slot limit and fast locking mechanism had been designed for the first time and the precision of battery system assembling could control within 3mm, hence the floating structure’s damage could be reduced and the mechanical life could be enhanced.
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.
Viewing 1 to 30 of 110610