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Viewing 91 to 120 of 6758
2017-03-28
Journal Article
2017-01-0011
Kesav Kumar Sridharan, Swaminathan Viswanathan
Abstract Current generation automobiles are controlled by electronic modules for performing various functions. These electronic modules have numerous semiconductor devices mounted on printed circuit boards. Solders are generally used as thermal interface material between surface mount devices and printed circuit boards (PCB) for efficient heat transfer. In the manufacturing stage, voids are formed in solders during reflow process due to outgassing phenomenon. The presence of these voids in solder for power packages with exposed pads impedes heat flow and can increase the device temperature. Therefore it is imperative to understand the effect of solder voids on thermal characteristics of semiconductor devices. But the solder void pattern will vary drastically during mass manufacturing. Replicating the exact solder void pattern and doing detail simulation to predict the device temperature for each manufactured module is not practical.
2017-03-28
Technical Paper
2017-01-0188
Yoichiro Higuchi, Hiroyuki Kobayashi, Zhiwei Shan, Mikiharu Kuwahara, Yoshiharu Endo, Yuha Nakajima
Abstract As vehicle emission regulations become increasingly rigorous, the automotive industry is accelerating the development of electrified vehicle platforms such as Battery Electric Vehicles (BEV) and Plug-in Hybrid Electric Vehicles (PHEV). Since the available waste heat from these vehicles is limited, additional heat sources such as electric heaters are needed for cabin heating operation. The use of a heat pump system is one of the solutions to improve EV driving range at cold ambient conditions. In this study, an efficient gas-injection heat pump system has been developed, which achieves high cabin heating performance at low ambient temperature and dehumidification operation without the assistance of electric heaters in ’17 model year Prius Prime.
2017-03-28
Technical Paper
2017-01-0250
Jizhou Zhang, Jianhua Zhou, Mian LI, Min Xu
Abstract Manufacturing of the internal combustion engines (ICEs) has very critical requirements on the precision and tolerance of engine parts in order to guarantee the engine performance. As a typical complex nonlinear system, small changes in dimensions of ICE components may have great impact on the performance and cost of the manufacturing of ICES. In this regard, it is still necessary to discuss the optimization of the tolerance and manufacturing precision of the critical components of ICEs even though the tolerance optimization in general has been reported in the literature. A systematic process for determining optimal tolerances will overcome the disadvantages of the traditional experience-based tolerance design and therefore improve the system performance.
2017-03-28
Technical Paper
2017-01-0323
Rosa Radovanovic, Samuel J. Tomlinson
Abstract Press-in-place gasket stability is required to maintain consistent and predictive sealing compression in a sealing joint utilizing a housing groove and a mating component sealing surface. Without proper balance between height of the groove and height of the gasket, the sealing joint can be compromised. Hence, automotive engineers balance design variables with the desire to achieve long term sealability and gasket stability. The percentage of gasket out of groove was varied to study the interactions of this design control and the resultant deviation of gasket centerline to the groove centerline. Finally, an optimal percentage of gasket out of groove is recommended.
2017-03-28
Technical Paper
2017-01-0366
Xingyu Liang, Yuesen Wang, Shuhe Huang, Guichun Yang, Lin Tang, Guoqi Cui
Abstract Due to the mechanical forces under static conditions, the engine cylinders cross section will not be a round circle any more once they are installed. The deformation of an engine cylinder causes increasing lubricating oil consumption and abnormal wear, resulting in worse fuel economy and emissions. However, prediction of deformation on a liner has not been made because of the complication of conditions and structure. In this study, a V6-type engine body model was built and meshed with Hypermesh suit software. Then, cylinder deformation under static condition has been simulated and analyzed. First of all, experimental work was done to verify the engine model. Basically, few parameters like pre-tightened force, structure and distribution of bolts have been investigated to figure out how the cylinder bore deformation behaves via finite element analysis. Also, a simple Matlab program was developed to process the data.
2017-03-28
Technical Paper
2017-01-0460
Erina Yasuda, Hiroki Kobayakawa, Seiji Amano, Yuto Otsuki, Tomohiro Ukai
Abstract The number of vehicles with engines using idling stop systems and hybrid systems to improve fuel consumption has recently been increasing. However, with such systems the frequent starts and stops of the engine, where the oil film between the bearings and shaft is squeezed out and direct contact between the components is more likely, can result in increased wear of the engine bearings, particularly in the main bearing. Bearings with resin overlays have been shown to display superior resistance to wear from such start-stop cycles. Moreover, cast iron shafts without quenching treatment have also been used in engines for cost reduction. Because the cast shaft has low hardness and unstable surface graphite after abrasive finishing, increase in the wear amount cannot be suppressed by conventional resin overlay in comparison with steel shaft. Therefore, the resin overlay with improved wear resistance achieved by adding hard particles was developed.
2017-03-28
Journal Article
2017-01-0131
Chiranth Srinivasan, Chonglin Zhang, Haiyang Gao, De Ming Wang, Jody Slike
Abstract In an automotive cooling circuit, the wax melting process determines the net and time history of the energy transfer between the engine and its environment. A numerical process that gives insight into the mixing process outside the wax chamber, the wax melting process inside the wax chamber, and the effect on the poppet valve displacement will be advantageous to both the engine and automotive system design. A fully three dimensional, transient, system level simulation of an inlet controlled thermostat inside an automotive cooling circuit is undertaken in this paper. A proprietary CFD algorithm, Simerics-Sys®/PumpLinx®, is used to solve this complex problem. A two-phase model is developed in PumpLinx® to simulate the wax melting process. The hysteresis effect of the wax melting process is also considered in the simulation.
2017-03-28
Journal Article
2017-01-1043
Yang Liu, Tian Tian
Abstract A new ring pack model has been developed based on the curved beam finite element method. This paper describes the first part of this model: simulating gas pressure in different regions above piston skirt and ring dynamic behavior of two compression rings and a twin-land oil control ring. The model allows separate grid divisions to resolve ring structure dynamics, local force/pressure generation, and gas pressure distribution. Doing so enables the model to capture both global and local processes at their proper length scales. The effects of bore distortion, piston secondary motion, and groove distortion are considered. Gas flows, gas pressure distribution in the ring pack, and ring structural dynamics are coupled with ring-groove and ring-liner interactions, and an implicit scheme is employed to ensure numerical stability. The model is applied to a passenger car engine to demonstrate its ability to predict global and local effects on ring dynamics and oil transport.
2017-03-28
Journal Article
2017-01-1073
Robert Huber, Jan Clauberg
Abstract The object of this study is a new chain tensioner with two labyrinth seals. For the simulation of chain tensioners within the framework of multi-body dynamics, a physically orientated model to describe the fluid dynamics of the labyrinth seals is derived. The easiest way to describe labyrinth seals is to use maps obtained from measurements. As this is very time-consuming, methods of 1D and 2D fluid-mechanics are used in this work to model the labyrinth seals. The seals are characterized by physically motivated parameters e.g. coefficients of resistance or friction. As these parameters can be derived from geometric data, a very good forecast feasibility without experimental investigations is provided. For high accuracy simulations model parameters can be refined by experimental data. As many and highly complex parameters have to be identified, this refinement is very time-consuming and requires lots of experiments.
2017-03-28
Journal Article
2017-01-0704
Noriyuki Takada, Takeshi Hashizume, Terutoshi Tomoda, Kazuhisa Inagaki, Kiyomi Kawamura
Abstract Generally, soot emissions increase in diesel engines with smaller bore sizes due to larger spray impingement on the cavity wall at a constant specific output power. The objective of this study is to clarify the constraints for engine/nozzle specifications and injection conditions to achieve the same combustion characteristics (such as heat release rate and emissions) in diesel engines with different bore sizes. The first report applied the geometrical similarity concept to two engines with different bore sizes and similar piston cavity shapes. The smaller engine emitted more smoke because air entrainment decreases due to the narrower spray angle. A new spray design method called spray characteristics similarity was proposed to suppress soot emissions. However, a smaller nozzle diameter and a larger number of nozzle holes are required to maintain the same spray characteristics (such as specific air-entrainment and penetration) when the bore size decreases.
2017-03-28
Journal Article
2017-01-1032
Xavier Llamas, Lars Eriksson
Downsizing and turbocharging with single or multiple stages has been one of the main solutions to decrease fuel consumption and harmful exhaust emissions, while keeping a sufficient power output. An accurate and reliable control-oriented compressor model can be very helpful during the development phase, as well as for engine calibration, control design, diagnostic purposes or observer design. A complete compressor model consisting of mass flow and efficiency models is developed and motivated. The proposed model is not only able to represent accurately the normal region measured in a compressor map but also it is capable to extrapolate to low compressor speeds. Moreover, the efficiency extrapolation is studied by analyzing the known problem with heat transfer from the hot turbine side, which introduces errors in the measurements done in standard gas stands.
2017-03-28
Journal Article
2017-01-1005
Yizhou Zhang, Jaal Ghandhi, David Rothamer
Abstract The effect of direct-injected fuel on particle size distributions (PSDs) of particulate matter emitted from dual-fuel combustion strategies was investigated. The PSD data were acquired from a light-duty single-cylinder diesel engine operated using conventional diesel combustion (CDC) and two diesel/natural gas dual-fuel combustion strategies. Three different direct-injection (DI) fuels (diesel, 2,6,10-trimethyldodecane, and a primary reference fuel blend) and two different injector nozzles were studied. The DI fuels were chosen to have similar energy and ignition characteristics (heat of combustion and cetane number) but different physical and chemical properties (volatility, aromatics %, viscosity, density). The two nozzles (with different orifice diameter and spray angle) allowed a wide range in DI fuel quantity for the dual-fuel combustion strategies.
2017-03-28
Journal Article
2017-01-1047
Yang Liu, Yuwei Li, Tian Tian
Abstract A new ring pack model has been developed based on the curved beam finite element method. This paper describes the second part of this model: simulating oil transport around the ring pack system (two compression rings and one twin-land oil control ring (TLOCR)) through the ring-liner interfaces by solving the oil film thickness on the liner. The ring dynamics model in Part 1 calculates the inter-ring gas pressure and the ring dynamic twist which are used in the ring-liner lubrication model as boundary conditions. Therefore, only in-plane conformability is calculated to obtain the oil film thickness on the liner. Both global process, namely, the structural response of the rings to bore distortion and piston tilt, and local processes, namely, bridging and oil-lube interaction, are considered. The model was applied to a passenger car engine.
2017-01-10
Technical Paper
2017-26-0279
Onkar P Bhise, S Ravishankar
Abstract Polytetrafluoroethylene (PTFE) is used extensively as the inner tube material in various Aerospace and Industrial hose constructs. The fluoropolymer exhibits various unique mechanical properties from other fluoropolymers including chemical inertness, non-adhesiveness and low friction coefficient making it an attractive solution for hose applications. PTFE material can be modeled using various material modeling approaches including linear-elastic, hyperelastic and viscoplastic depending on the level of accuracy required in predicting material response. Fluoropolymers, like PTFE, are considered viscoelastic-viscoplastic materials. In other words, the material exhibits both viscous and elastic characteristics when undergoing deformation but also possesses behavior in which the deformation of the material also depends on the rate by which loads are applied.
2017-01-10
Technical Paper
2017-26-0267
Durga Prasad Mohapatra, Suhas Kangde, Abhijit Londhe, N N Srikanth, Pravin Singh
Abstract Exhaust system is one of the complex automotive systems in terms of performance and strength prediction due to combination of transient mechanical and thermal loads acting on it simultaneously. Traditionally, most of automotive vehicles have exhaust systems with hot end mounted on engine and cold end mounted on chassis or BIW through hangers. A new powertrain mounted exhaust system was developed in-house. This exhaust system underwent validation and evaluation during development phase. Durability concerns were observed on exhaust system in Track test and gear shift durability test. This paper focuses on identifying the root cause of these concerns based on the failures observed during evaluation in Accelerated Durability (ADT) and gear shift durability (GSD) tests. Based on the architecture and packaging space challenges in vehicle, engine is mounted on two mounts and a roll restrictor.
2017-01-10
Technical Paper
2017-26-0274
Kaarthic Kaundabalaraman
Abstract Proper suitability of bolt preload is a pre-requisite whenever we go for component design change. In this paper we have considered connecting rod bolt for our analysis, where-in the design pre-requisite was whether same tightening specification could be carried forward from normal to fracture split type. The present work focuses on comparison of bolt design parameters, inertia force, contact pressure & bearing pressure calculation. Bolt safety factor was used as a parameter to check for the preload suitability with respect to engine max permissible speed. A systematic approach, considering guidelines from available bolt standard and literature was used for carrying out related analysis. For improving the quality of judgment, FEA tools along with durability testing was carried out at ARAI. In addition to this for better bolt preload control “Angle tightening method” of required specification was proposed, with results validated through physical testing.
2017-01-10
Technical Paper
2017-26-0367
Prasad S. Warwandkar, Ashutosh Dubey, Sonu Paroche
Abstract Wheel end bearing is one of the critical components of the vehicle as it directly faces the road loads for harsh operating environment. Bearing being a precisely manufactured component and rotating at high speed, utmost care is required while assembling as well as during operation. In operating condition wheel end is directly exposed to outside environment making it prone to entry of contamination. This contamination if not prevented from entering into wheel end through proper sealing it would cause lubricant contamination and consequently bearing failure. Bearing replacement and overall wheel end service is time consuming activity reducing the turn out time of the vehicle. In wheel ends, one side is sealed with the help of seal while the other side is protected by cap and gasket. This cap-gasket interface is very critical from sealing perspective and utmost importance needs to be taken while designing the same.
2017-01-10
Technical Paper
2017-26-0170
Pratik Pillai, Sivakumar Venugopal, Vijaysankar Gopalan
This paper deals with the study of the phenomenon of crevice corrosion of aluminium by using an example of a corrosion failure of a joint in the automobile coolant circuit. A number of joint failures were studied to understand the corrosion pattern and for various metallurgical aspects like chemistry, hardness and microstructure. The corrosion products were analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS). This analysis indicated that the corrosion products mostly contained Aluminium Oxides with other contaminants like chlorides. The studies revealed that the clamped joint of the aluminium part and rubber hose led to the formation of a crevice with the engine coolant acting as the corrosive medium. The corrosion behavior at the location was affected by environmental factors like temperature, pH and chloride contamination.
2017-01-10
Technical Paper
2017-26-0173
Surbhi Bhagwat, Vinod Kumar Mannaru
Abstract Forging is one of the traditional bulk metal forming processes used extensively in the automotive industry. Forging has a distinct advantage versus other metal manufacturing processes in terms of strength, grain orientation, reliability, near net shape with lower material utilization, and machining requirements leading to cost effectiveness, etc. Today, the automotive industry is going through the critical phase of reducing component costs through material reduction and optimized tool consumption. With this challenge, process modeling is gaining more momentum in the industry to optimize blank size and improve the tool life with required part quality, while also evaluating press tonnage requirements for effective equipment usage. It also enables integrated process modeling by understanding the microstructure, residual stress/deformation built into the manufactured part, and integrating with material property changes for subsequent part performance prediction.
2017-01-10
Technical Paper
2017-26-0191
Mayur Birari, Arvind Yadav, Vilas Bijwe, Dayanand Billade
Abstract As automotive technology has evolved, gear rattle has become a prominent contributor for cabin noise as the masking from the engine noise has decreased. The market and customer expectation make the rattle noise a question to be addressed as early as possible in the vehicle development process. However, to simulate rattle, it calls for a detailed modeling of different complex subsystems of driveline to represent their true characteristics. Thus, the paper adopts an FE based elastic multi body dynamics model to predict gear rattle. The approach involves modeling of a complete flexible driveline using condensed FE models from Nastran in AVL Excite Powerunit/Transmission module. It includes combustion pressure as input excitations to crankshaft and then predicts parameters like gear teeth impacts, gear normal meshing force, dynamic mesh stiffness & overall contact state in transient and frequency domain. The output parameters are then analyzed to evaluate the rattle index.
2017-01-10
Technical Paper
2017-26-0149
Ganeshan Reddy, R Suresh, Josebel Raj Regin, Rajiv Modi, Agha Seraj Husain
Abstract The present scenario in automobile industry is formed on developing smart vehicles by introducing various feature towards fuel efficient, low emission, weight reduction, and advance safety feature with hybrid and micro-hybrid vehicles. One such feature gaining more popularity is the Belt Driven Starter Generator [1] for its contribution towards fuel efficiency, emission reduction [2], weight reduction and convenient packaging with engine/electrical interface. However this invention puts challenge of integration and increase in loading to various system like power steering pump and crank shaft pulley, as all these systems are interlinked with a common belt. In this interface links we observed the steering pump hub under risk of structural failure due to additional load to support Belt Driven Starter Generator. Failure to identify safe limits of hub load can affect safe vehicle operation [3].
2017-01-10
Technical Paper
2017-26-0159
B Sakthivel, R Elayaraja, M Sivakumar, R Sridhar, J Suresh Kumar, B L Ganapati Subramaniyam
Abstract Solenoids are electro mechanical actuators used in automotive industries as flow control valve. Solenoids replace the conventional mechanical valve since it is having a precise control and faster response. Solenoid is operated either in ON/OFF mode or Pulse Width Modulation mode (PWM). When operated in PWM at a given frequency, the solenoid undergoes finite number of repeated operations. A normally closed solenoid contains two critical parts, one is a plunger, which is a moving part and another is valve case, which is a static part. The plunger hits the valve case during repeated number of operations which undergo extreme wear. Since the functionality and performance of the solenoid mainly rely on the plunger and valve case, it is inevitable to have an optimum material selection in order to achieve higher durability. This paper illustrates the study of material selection for an air control solenoid used for two wheeler application.
2017-01-10
Technical Paper
2017-26-0051
Praveen Babu Kandavalli, Ramanathan Karthi, Suresh Suresh Kumar, M Anand
Abstract Lubrication system is a critical factor for engine health. But it creates parasitic load and increased fuel consumption of the engine. The oil demand of an engine depends on engine speed, load, bearing clearances, operating temperature and engine's state of wear. Ideally, the oil pump should adapt the delivery volume flow to actual engine oil demand and should avoid unnecessary pumping of oil which causes increased power and fuel consumption. However in a conventional mechanical oil pump, there is no control on the oil flow and it is purely a function of operating speed. A variable discharge oil pump (VDOP) is an approach to reduce the parasitic losses wherein the oil flow is regulated based on the mechanical needs of the engine. This study is based on the results of a two stage VDOP installed on a 1.2 litre, 3 cylinder MPFI engine. The oil supply is regulated by a solenoid control which receives command from Engine Control Unit (ECU). The study was done in two stages.
2017-01-10
Journal Article
2017-26-0227
Babu Bhondave, T Ganesan, Naveen Varma, Rajasekar Renu, N Sabarinath
Abstract Tractor hitch control system is used for attaching and operating various Agricultural Implements and for operating tipping trailer. The system has also got provision to attach additional Aux valves for rear and front mounted attachments. The rear mounted implements are coupled to the tractor using Three Point Linkage (3PL) System. The hitch hydraulics system consists of hydraulic pump, filter, piping’s, fittings and hydraulics lift unit. Hydraulics lift unit consists of a proportional control valve, cylinder, piston and power linkages. Conventional control valve is hydro mechanical part operated by mechanical linkages. The control valve and linkages plays major role in performance of hydraulics system. Hydraulics is required to operate in extreme conditions of soils such as very soft like sand to very hard like black cotton sand.
2017-01-10
Journal Article
2017-26-0233
Solairaj Perumal, Abhay Kumar, Arun Mahajan, Dinesh Redkar, Sureshkumar Balakrishnan
Abstract The tractor engine related mounting brackets are very critical due to different aspects of vehicle performance, durability and noise. These mounting bracket have been designed as a framework to support engine external parts like muffler, exhaust tail pipe, alternator etc. Vibration and fatigue has been continuously a concern which may lead to structural failure and performance issues. Various such failures are faced regularly by automotive industry and finite element based analysis are used to resolve them. The resolution is done by playing with the component thicknesses, material, by providing additional support etc. However, due to large degree of uncertainty associated with the loading, boundary conditions, manufacturing, environmental effects; still there is some probability of failure. This paper focuses on a field failure issue of an exhaust system of a tractor and subsequent concern resolution.
2017-01-10
Journal Article
2017-26-0291
Vishwas Shantaram Waghmare, Vaibhav Salunkhe, Rakesh Nagrani, Vishal Guttal
Abstract This paper presents a stepwise approach for exhaust system mount scheme finalization from concept to detail design phase. Finalization of exhaust hanger locations by finding Nodal points on exhaust system were considered. Various generic aspects like frequency separation, mode shapes, reaction forces, static displacement, and stress were considered. Apart from the generic aspects special aspects like peak loads and operating conditions were also considered. A combination of design of experiments (DoE) and optimization was used to finalize the mounting scheme and mounting characteristic parameters.
2017-01-10
Journal Article
2017-26-0308
Shiva Kumar Manoharan, Christopher Duempelmann, Christoph Friedrich
Abstract This paper shows an approach developed to cover in detail different behaviour of threaded fasteners with a robust test setup for multibolted joints and numerical simulations by means of finite element analysis (FEA). Resulting from this combination, it is possible to monitor the axial, torsion and bending stress in fasteners themselves. Importance is given to interpretation of the measurement signals of strain gauge bolts. Integrity of the complete structure can be better interpreted with this approach. This depends on the modelling of bolts for FEA and the quality of the measured signals from experiments. For FE modelling the general purpose non-linear solver Abaqus is used, for preload measurement strain gauges are integrated into metric bolts. Simulation and experimental results from this unique test setup with several bolts are shown.
2016-11-08
Technical Paper
2016-32-0021
Stephen Gurchinoff
Abstract This technical paper will provide supporting lubricated test data for the use of thermoplastics like polyamide-imide (PAI) and polyetheretherketone (PEEK) in demanding wear applications at temperatures up to 285°C and pressure velocity exceeding one million psi·ft/min. Applications include needle bearing replacement in transmissions, journal bearings, pumps, marine lower units, continuous variable transmissions, and others. These materials have been used in automotive transmission applications for over 20 years and can be similarly used in small engine applications. By using a thermoplastic, applications benefit through reduced noise and vibration harshness, reduced space, and reduced weight. Mechanical property differences throughout operating temperatures will also be reviewed.
2016-11-08
Technical Paper
2016-32-0025
Govardan Daggupati, Bapanna Dora Karedla, Chandan Bansilal Chavan, Gagandeep Singh Risam
Abstract In two wheelers the front suspension system is mounted on chassis by two steering bearings which are lubricated ball type angular contact bearings with significant radial force components. These bearings are designed to withstand maximum vehicle loads for target durability. Maximum load carrying capacity depends on the number and size of the balls, bearing size and material. For target durability with designed load carrying capacity, the ball contact pressure, bearing preload plays a major role as compared to other design parameters. Geometry parameters and maximum load defines contact pressure for given bearing design. But in two wheelers due to nature of usage and road conditions, the peak loads are dynamic and geometry based design calculations may not yield the most optimal bearing design. In this work the bearing ball race profile design is optimized by using dynamic bearing contact profiles by using nonlinear Finite Element Analysis.
2016-11-08
Technical Paper
2016-32-0064
Keiya Nishida, Takeru Matsuo, Kang Yang, Youichi Ogata, Daisuke Shimo
Abstract The injection amount per stage in a multiple injection strategy is smaller than a conventional single-stage injection. In this paper, the effect of the injection amount (0.27mg, 0.89mg, 2.97mg) under 100MPa injection pressure and the effect of injection pressure (100MPa, 150MPa, 170MPa) under different injection amounts (0.27mg, 2.97mg) on the spray and mixture formation characteristics were studied by analyzing the vapor/liquid phase concentration distributions obtained under various conditions via using the tracer LAS technique. The spray was injected into a high-pressure and high-temperature constant volume vessel by using a single-hole nozzle with a diameter 0.133mm. The higher the injection pressure with a smaller injection amount is, the shorter the spray tip penetration and leaner air-fuel mixture occur. The combustion processes had been examined by a high-speed video camera with the two-color pyrometry method.
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