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Viewing 151 to 53 of 53
2016-04-05
Journal Article
2016-01-0493
Roger Gorges, David Latham, Ian Laing, Ronald Brock
Abstract Modern High-Speed Diesel (HSD) engines place increasing demands on engine components. Specifically, for connecting rod bearings there is a requirement to endure increased peak cylinder pressures and the resulting loads transmitted through the connecting rods to the crankshaft. In addition to these high loads, the operating environment for bearings is becoming more aggressive. Reductions in oil film thickness combined with the move towards lower viscosity oils means that the seizure and wear resistance of the bearings play a crucial role in modern engine development. In order to attend to these demands, MAHLE has developed a novel high-performance polymer coating containing lubricant-filled microcapsules. The Microcapsules are designed to rupture during nascent scuff and high wear events and consequently release the contained lubricant ‘on demand’. This introduces additional lubrication when required to prevent seizure.
2016-04-05
Journal Article
2016-01-1376
Feng Qi, Sujan Dhar, Varun Haresh Nichani, Chiranth Srinivasan, De Ming Wang, Liang Yang, Zhonghui Bing, Jinming Jim Yang
Abstract External gear pumps are positive displacement devices which perform with excellent efficiencies over a wide load and speed range. This wide range of performance is primarily due to micron-level leakage gaps in such machines which prevent large leakages at increasing loads. The present paper details a novel approach implemented in the commercial CFD tool PumpLinx that can capture the details of the micron level gaps, and model such machines accurately. The steps in creation of the model from original CAD geometry are described. In particular, the CFD mesh is created using a specialized template structured meshing method within PumpLinx especially created for external gear pumps and motors. This makes process of mesh creation and flow solution through complicated geometries of a gear pump efficient and streamlined.
2016-04-05
Journal Article
2016-01-0485
Jiaqi Li, Jimin Ni, Qiwei Wang
Abstract Turbochargers improve performance in internal combustion engines. Due to low production costs, TC assemblies are supported on floating ring bearings. In current lubrication analysis of floating ring bearing, inner and outer oil film are usually supposed to be adiabatic. The heat generated by frictional power is carried out by the lubricant flow. In reality, under real operating conditions, there existed heat transfer between the inner and outer film. In this paper, the lubrication performance of floating ring bearing when considering heat transfer between inner film and outer film is studied. The lubrication model of the floating ring is established and the heat transferred through the ring between the inner and outer film is calculated. The calculation results show that heat flow between the inner and outer film under different outer film eccentricity ratio and rotate ratio has a large difference.
2016-04-05
Journal Article
2016-01-0261
Lili Feng, Predrag Hrnjak
Abstract This paper presents a simulation model for a reversible air conditioning and heat pump system for electric vehicles. The system contains a variable speed compressor, three microchannel heat exchangers, an accumulator, and two electronic expansion valves. Heat exchangers are solved by discretizing into cells. Compressor and accumulator models are developed by fitting data with physical insights. Expansion valves are modeled by isenthalpic processes. System performance is calculated by connecting all parts in the same way as the physical system and solved iteratively. The model is reasonably validated against experimental data from a separate experimental study. Future improvement is needed to take into account maldistribution in outdoor heat exchanger working as an evaporator in HP mode. Charge retention in components also requires further study.
2016-04-05
Journal Article
2016-01-1560
Bo Lin, Chinedum E. Okwudire
Abstract Ball nut assemblies (BNAs) are used in a variety of applications, e.g., automotive, aerospace and manufacturing, for converting rotary motion to linear motion (or vice versa). In these application areas, accurate characterization of the dynamics of BNAs using low-order models is very useful for performance simulation and analyses. Existing low-order contact load models of BNAs are inadequate, partly because they only consider the axial deformations of the screw and nut. This paper presents a low-order load distribution model for BNAs which considers the axial, torsional and lateral deformations of the screw and nut. The screw and nut are modeled as finite element beams, while Hertzian Contact Theory is used to model the contact condition between the balls and raceways of the screw and nut. The interactions between the forces and displacements of the screw and nut and those at the ball-raceway contact points are established using transformation matrices.
2016-04-05
Journal Article
2016-01-0243
Jingwei Zhu, Stefan Elbel
Abstract Expansion work recovery by two-phase ejector is known to be beneficial to vapor compression cycle performance. However, one of the biggest challenges with ejector vapor compression cycles is that the ejector cycle performance is sensitive to working condition changes which are common in automotive applications. Different working conditions require different ejector geometries to achieve maximum performance. Slightly different geometries may result in substantially different COPs under the same conditions. The ejector motive nozzle throat diameter (motive nozzle restrictiveness) is one of the key parameters that can significantly affect ejector cycle COP. This paper presents a new two-phase nozzle restrictiveness control mechanism which is possibly applicable to two-phase ejectors used in vapor compression cycles.
2016-04-05
Journal Article
2016-01-0862
PengBo Dong, Keiya Nishida, Takuya Inaba, Youichi Ogata
Abstract The tiny and normal injection quantity instances usually happen under the multi-injection strategy condition to restrain the uncontrollability of the ignition timing of the homogeneous charge compression ignition (HCCI) combustion concept. Meanwhile, instead of the traditional and fundamental single-hole diesel injector, the axisymmetric multi-hole injectors are usually applied to couple with the combustion chamber under most practical operating conditions. In the current paper, the internal flow and spray characteristics generated by single-hole and multi-hole (10 holes) nozzles under normal (2 mm3/hole) and tiny (0.3 mm3/hole) injection quantity conditions were investigated in conjunction with a series of experimental and computational methods. High-speed video observation was conducted at 10000 and 100000 fps under the condition of 120 MPa rail pressure, 1.5 MPa ambient pressure, room temperature, and nitrogen environment to visualize different spray properties.
2016-04-05
Journal Article
2016-01-1027
Bertrand Kerres, Vineeth Nair, Andreas Cronhjort, Mihai Mihaescu
Abstract Turbocharger compressors are limited in their operating range at low mass flows by compressor surge, thus restricting internal combustion engine operation at low engine speeds and high mean effective pressures. Since the exact location of the surge line in the compressor map depends on the whole gas exchange system, a safety margin towards surge must be provided. Accurate early surge detection could reduce this margin. During surge, the compressor outlet pressure fluctuates periodically. The Hurst exponent of the compressor outlet pressure is applied in this paper as an indicator to evaluate how close to the surge limit the compressor operates. It is a measure of the time-series memory that approaches zero for anti-persistence of the time series. That is, a Hurst exponent close to zero means a high statistical preference that a high value is followed by a low value, as during surge.
2016-04-05
Journal Article
2016-01-1013
Matthieu Duchemin, Vincent Collee
Abstract MCE-5 DEVELOPMENT has been developing its variable compression ratio engine (VCRi) for over a decade aiming at reducing fuel consumption and pollutant emissions. In order to transmit power from the piston (combustion) to the crankshaft, the MCE-5 VCRi technology is based on three innovative components: a gear wheel and two racks. This gear mechanism ensures a very low friction compared to other continuous VCR solutions based on bearings. However, this transmission is used in nonstandard conditions: the direction of rotation is reversed repeatedly, and the parts are submitted to high and rapidly varying loads. To avoid interferences and alteration caused by high contact pressure at high load, and ensure a regular transmission at low load, the profile of the teeth is carefully considered. A crowning shape is placed on the teeth in the direction of the gear axis, and a correction is applied to the tooth active profiles in the area of tooth roots and tooth tips.
2016-04-05
Journal Article
2016-01-1078
Rıfat Kohen Yanarocak, Hakan Boz
Abstract In this paper, a simultaneous design and development work for a diesel engine valvetrain system is presented. The rocker arm is one of the most important components of the valvetrain system which is transmitting the energy between the valves and the camshaft. Valvetrain system becomes even more complicated, when the extreme high speed of the system and nonlinear character of combustion is combined with the unpredictable behavior of the hydraulic lost motion mechanism during engine brake. As the complexity increases, it gets harder to predict valvetrain stress values especially while engine brake is in action. By taking all of these effects into account, that is reducing reliability of virtual analysis, requirement to conduct a strain measurement on valvetrain became inevitable.
2016-04-05
Journal Article
2016-01-1081
Jonathan Harrison, Rodrigo Aihara, Fabian Eisele
Abstract Engine and transmission oil systems are commonly pressurized by gerotor style pumps, due to their simplistic design and low cost. Gerotor pumps are designed with certain tolerances of the gears and housing, thus creating a tradeoff of lower cost with larger tolerances and higher cost with smaller tolerances. By building a detailed gerotor pump model with a 1D hydraulic flow network, engineers can evaluate pump performance with these tolerances as input and compare to find the optimal design. This paper showcases the ease of building a gerotor model in 1D by using an automated process extracting the key model inputs directly from the pump CAD file. The gerotor pump performance is predicted including flow rate, total power loss, volumetric efficiency, and total efficiency vs. pump speed, pressure rise, clearance tolerances, and temperature, and compared with experiment.
2016-04-05
Journal Article
2016-01-1083
Kenji Sato, Takeru Hamakawa, Takeyuki Yamasaki, Yoshimichi Ishihara, Hisashi Hashimoto, Chao Shi, Hiroaki Haneda, Shinichi Takahashi, Yoshiyuki Iida
Abstract The independent bearing cap is a cylinder block bearing structure that has high mass reduction effects. In general, this structure has low fastening stiffness compared to the rudder block structure. Furthermore, when using combination of different materials small sliding occurs at the mating surface, and fretting fatigue sometimes occurs at lower area than the material strength limit. Fretting fatigue was previously predicted using CAE, but there were issues with establishing a correlation with the actual engine under complex conditions, and the judgment criteria were not clear, so accurate prediction was a challenge. This paper reports on a new CAE-based prediction method to predict the fretting damage occurring on the bearing cap mating surface in an aluminum material cylinder block. First of all, condition a fretting fatigue test was performed with test pieces, and identification of CAE was performed for the strain and sliding amount.
2016-04-05
Journal Article
2016-01-0776
Mateos Kassa, Carrie Hall, Andrew Ickes, Thomas Wallner
Abstract Advanced internal combustion engines, although generally more efficient than conventional combustion engines, often encounter limitations in multi-cylinder applications due to variations in the combustion process. This study leverages experimental data from an inline 6-cylinder heavy-duty dual fuel engine equipped with a fully-flexible variable intake valve actuation system to study cylinder-to-cylinder variations in power production. The engine is operated with late intake valve closure timings in a dual-fuel combustion mode featuring a port-injection and a direct-injection fueling system in order to improve fuel efficiency and engine performance. Experimental results show increased cylinder-to-cylinder variation in IMEP as IVC timing moves from 570°ATDC to 610°ATDC, indicating an increasingly uneven fuel distribution between cylinders.
2016-04-05
Journal Article
2016-01-0870
Kaushik Saha, Sibendu Som, Michele Battistoni, Yanheng Li, Eric Pomraning, P. K. Senecal
Abstract This work involves modeling internal and near-nozzle flows of a gasoline direct injection (GDI) nozzle. The Engine Combustion Network (ECN) Spray G condition has been considered for these simulations using the nominal geometry of the Spray G injector. First, best practices for numerical simulation of the two-phase flow evolution inside and the near-nozzle regions of the Spray G injector are presented for the peak needle lift. The mass flow rate prediction for peak needle lift was in reasonable agreement with experimental data available in the ECN database. Liquid plume targeting angle and liquid penetration estimates showed promising agreement with experimental observations. The capability to assess the influence of different thermodynamic conditions on the two-phase flow nature was established by predicting non-flashing and flashing phenomena.
2016-04-05
Technical Paper
2016-01-0554
José Galindo, Andrés Tiseira, Roberto Navarro, Daniel Tarí, Hadi Tartoussi, Stéphane Guilain
Abstract 0D-1D codes allow researchers to obtain a prediction of the behavior of internal combustion engines with little computational effort. One of the submodels of such codes is devoted to the centrifugal compressor. This model is often based on the compressor performance maps, therefore requiring the extrapolation of the maps so that all possible operating conditions are covered. Particularly, a suitable extrapolation of isentropic efficiency map is sought. This work first examines different available methods for compressor efficiency extrapolation into off-design conditions. No method is found to provide satisfactory results at all extrapolated regions: low and high compressor speeds and low compression ratio at measured speeds. Hence, a new method is proposed and its accuracy is assessed with the aid of compressor off-design measurements.
2016-04-05
Journal Article
2016-01-1597
Christopher Collin, Steffen Mack, Thomas Indinger, Joerg Mueller
Abstract The open jet wind tunnel is a widespread test section configuration for developing full scale passenger cars in the automotive industry. However, using a realizable nozzle cross section for cost effective aerodynamic development is always connected to the presence of wind tunnel effects. Wind tunnel wall interferences which are not present under open road conditions, can affect the measurement of aerodynamic forces. Thus, wind tunnel corrections may be required. This work contains the results of a CFD (Computational Fluid Dynamics) approach using unsteady Delayed Detached Eddy Simulations (DDES) to evaluate wind tunnel interferences for open jet test sections. The Full Scale DrivAer reference geometry of the Technical University of Munich (TUM) using different rear end shapes has been selected for these investigations.
2016-04-05
Journal Article
2016-01-0092
Stijn Kerst, Barys Shyrokau, Edward Holweg
Abstract Active vehicle safety and driving assistance systems can be made more efficient, more robust and less complex if wheel load information would be available. Although this information could be determined via numerous different methods, due to various reasons, no commercially feasible approach has yet been introduced. In this paper the approach of bearing load estimation is topic of interest. Using the bearing for load measurement has considerable advantages making it commercially attractive as: i) it can be performed on a non-rotating part, ii) all wheel loads can be measured and iii) usually the bearing serves the entire lifetime of the vehicle. This paper proposes a novel approach for the determination of wheel loading. This new approach, based on the strain variance on the surface of the bearing outer ring, is tested on a dedicated bearing test setup.
2016-02-01
Technical Paper
2016-28-0082
Venu Ganti, Yogesh Kumar Dewangan, Ganesan Subramanian
Abstract In an automotive transmission system, gear mesh misalignment implies the shift in the position of the meshing surfaces. Misalignment at the mesh results in non-uniform load distribution leading to gear failure, increased noise and thus affects the transmission performance. In general, misalignment along the line of action (MLOA) of 0-5 mrad is common in the gear meshes of automotive transmissions. Major factors contributing to mesh misalignment are deflections of various elastic components in the transmission like shaft, gear web, bearing, housing etc. Contribution from other factors include clearance between the components, temperature gradient and manufacturing process limitations. Different approaches for compensating gear mesh misalignment involves control over the above factors at design and manufacturing stages. This paper focuses on three different approaches for compensating MLOA in the design stage.
2016-02-01
Technical Paper
2016-28-0172
Praharsh Srivastava, Kamal Sharma, Raushan Jha
Abstract Rapid advent of mobile air conditioning industry has witnessed a wide use of fixed displacement swash plate compressor due to its small size, compact structure and light weight. An accurate prediction of volumetric efficiency and power of compressor at early stages of design serves as a very useful information for designer. No work regarding the power and volumetric efficiency prediction for double headed fixed displacement swash plate compressor is reported in the existing literature. This paper presents a mathematical model for a double acting fixed displacement swash plate compressor with the objective of evaluating the shaft torque and volumetric efficiency of compressor. Shaft torque, in turn is a measure of compressor power. The geometrical description of swash plate yields a kinematic model to obtain the piston displacement as an explicit function of angle of rotation of shaft.
2016-02-01
Technical Paper
2016-28-0175
Siddharth Dahiya, Adithya Asok Sharma, Rahul Srinivasan, Ritesh Tekriwal, Kamalkishore Vora, B Ashok, C Kavitha
Abstract This paper describes the design methodology and algorithm development towards the design of an automatic external gear-shifting and clutch-actuation system for a sequential gearbox with the aim of providing the drivers with easier and an efficient means of shifting gears. Automatically actuated manual transmission system bridges the gap between automatic and manual transmissions which provides the advantages of both type of transmissions. This would ideally leads to faster shifting time and provide significant benefits in the form of electronic-aids like launch control and traction control. Removal of mechanical clutching would reduce fatigue and lead to ergonomic benefit. Based on the benchmarking performed on an easily available ready-to-install aftermarket alternative, options will be considered for the actuating mechanism and the most feasible will be used to develop a shifting system.
2016-02-01
Technical Paper
2016-28-0224
Akshay Ramesh Karjol, Ajay Virmalwar
Abstract Reducing overall weight of the vehicle is one of the main areas of research in automotive industries. Current trend, CO2 reduction, is a major incentive for this process. For this, engineers are finding out various ways to reduce weight to strength ratio of the different components. The immediate pay-off of such developments is lower fuel consumption, which is followed by lower CO2 emissions. For this engineers opt for, use of low-density and high-strength materials, along with optimization of the geometry of the components. One of the solutions is to convert metal parts to plastics which have desired properties. The main focus of this paper is to convert the sheet metal brackets to plastic brackets which will ultimately reduce weight and production cost associated with automobile. In this paper, an optimum process, using Topology optimization and Mold Flow Analysis, is developed to convert sheet metal bracket to plastic bracket.
2016-02-01
Technical Paper
2016-28-0251
Kantilal Patil, Siva Reddy, Nadeem Zafar
Abstract In the event of a frontal car crash, occupant sitting in a car meets various types of injuries like Head injury, Chest compression, Neck injury etc. These injuries may lead to the death of an occupant if exceeded beyond biomechanical limits. Seat belt is a primary restraint system, which when worn controls the motion of occupant sitting inside the car during the event of a car crash. An Anchorage location of three point seat belt system has significant effect on occupant injuries during the crash event. By changing the mount locations of a seat belt anchor points i.e. D-ring, Anchor & Buckle, performance of seatbelt system can be enhanced further thereby reducing occupant injuries to certain extent. As per regulation AIS015, locations of safety belt anchorage points should be within prescribed zone.
2016-02-01
Technical Paper
2016-28-0001
Akhilendra Pratap Singh, Suresh Gadekar, Avinash Kumar Agarwal
Abstract Fuel-air mixing is the main parameter, which affects formation of NOx and PM during CI combustion. Hence better understanding of air-flow characteristics inside the combustion chamber of a diesel engine became very important. In this study, in-cylinder air-flow characteristics of four-valve diesel engine were investigated using time-resolved high-speed tomographic Particle Imaging Velocimetry (PIV). For visualization of air-flow pattern, fine graphite particles were used for flow seeding. To investigate the effect of different operating parameters, experiments were performed at different engine speeds (1200 rpm and 1500 rpm), intake air temperatures (room temperature and 50°C) and intake port configurations (swirl port, tangential port and combined port). Intake air temperature was controlled by a closed loop temperature controller and intake ports were deactivated by using a customized aluminum gasket.
2016-02-01
Technical Paper
2016-28-0113
Anurag Kamal, Kaarthic Kaundabalaraman, Hemantkumar Rathi, Alok Muley
Abstract This work is an effort to find the parallelism between the volumetric efficiency of a Gerotor, and its inherent design parameters: number of teeth, tooth profile, outer dimensions of diameter and thickness, and the input power (torque and speed). The preliminary relations are derived from the software simulation of a range of Gerotor models with varying aforementioned parameters. These results are augmented by a previously proposed method of theoretically estimating the displacement of a Gerotor. Then, these results are validated and revised by practical results from three different Gerotors with epitrochoidal and its conjugate profiles, which are used in automotive applications like engines and transmissions. These relations can be used for choosing parameters yielding the maximum efficiency in specific environments: the packaging space, the input available, and the output required.
2016-02-01
Technical Paper
2016-28-0118
J. Sureshkumar, K. Vijayakumar, R. Elayaraja
Abstract The main challenge in today's modern engines is to design the parts, which should withstand higher temperatures. To achieve this, selection of materials and process tolerances are very important factors. The product identified in this study is a conventional oil pump, which is an engine auxiliary component. The function of the oil pump is to supply oil to different parts of the engine to lubricate and reduce the overall engine friction. The different speed and load conditions for which the engine is subjected, pose a challenge to the oil pump, to supply the necessary quantity of oil at the required pressure and temperature. Normally, the oil pump is subjected to a temperature of 120°C at higher speeds. However, the peak oil temperature in modern diesel engines can be as high as 140°C to 150°C for a short period of time. For this study, two engine grade oils were selected. Numerical analysis was performed to predict the oil flow rate for these oil grades.
2016-01-01
Journal Article
2015-01-9085
Vinod Upadhyay, Xiaoning Qi, Nick Wilson, Dante Battocchi, Gordon Bierwagen, Joy Forsmark, Robert McCune
Abstract This work reports on measurement and analysis of the galvanic interaction between steel self-piercing rivets (SPRs) having several different surface conditions and magnesium alloy substrates under consideration for use in automotive structural assemblies. Rivet surface conditions included uncoated steel, conventional Zn-Sn barrel plating and variations of commercial aluminizing processes, including supplemental layers and sealants. Coating characteristics were assessed using open circuit potential (OCP) measurement, potentiodynamic polarization scanning (PDS), and electrochemical impedance spectroscopy (EIS). The degree of galvanic coupling was determined using zero-resistance ammeter (ZRA) and the scanning vibrating electrode technique (SVET), which also permitted characterization of galvanic current flows in situ.
2015-11-17
Technical Paper
2015-32-0742
Kenta Goto, Shinji Noda, Kohei Nakashima, Yoshio Murakami
To improve engine torque and specific fuel consumption in a supermilage vehicle, we experimentally adjusted the valve lift and opening period in rocker arms, testing various follower configurations and adjust screws. Using the follower configuration in a commercially-available rocker arm, we compared 4 different levels of valve lift and opening period in the intake, and 4 different levels in the exhaust, making 16 combinations. Then, utilizing 5 kinds of modified follower configurations of the rocker arms in the intake, and 3 in the exhaust, we also compared 24 combinations (including the commercially-available follower configurations). We tested our experimental supermilage engine under full-load at 2000 to 4500rpm, simulating powering a supermilage vehicle.
2015-11-17
Technical Paper
2015-32-0701
Takayuki Sugita
An existing 4 stroke-cycle gasoline engine has been partially modified without dynamically changing its mechanism for the purpose to utilize the compressed air as an alternative energy source. The principle is to mechanically control the compressed air flow through the intake and exhaust valve every revolution of a crankshaft by modifying the camshaft cam's lobes, which changes the engine operation from 4 strokes to 2 strokes cycle mode. In the previous investigation the principle was verified with a current 50 cc motorcycle modified engine and the pressure behavior inside the cylinder of the compressed air engine was evaluated. It turned out as a most promising result that the back pressure, which is defined as the positive pressure left in an expansion chamber while a piston is moving back from BDC to TDC, has a high influence on the performance of the compressed air reciprocating engine.
2015-11-17
Journal Article
2015-32-0743
Hiroyuki Yoshida, Hiroshi Hirayama, Shinsuke Mochizuki, Manabu Inoue, Yasuhiro Kato, Toshiki Inomata
A black surface treatment without using hexavalent chromium and applicable to bolts of motorcycles has been developed. The surface treatment also satisfies the requirements of bolts for motorcycles such as fastening performance, corrosion resistance, weather resistance and appearance of outer finish. There is a method of coating a black chemical conversion film using trivalent chromium on the zinc-plated surface as one of the surface treatments that do not use the hexavalent chromium. Such a black film, however, is thinner than the film using hexavalent chromium, and unable to ensure satisfactory black appearance. Meanwhile, although the dip-coating using a black paint can provide a sufficient black color, it is necessary to apply coating two times to eliminate an irregular color. As a result, thick paint films are formed on the roots of thread, making it difficult to fit into the internal thread. To simultaneously solve the above-mentioned two issues, two measures were executed.
2015-09-29
Technical Paper
2015-01-2765
Shannon K. Sweeney
Abstract This paper presents simple but comprehensive modeling of the loads on the rubber sandwich-type mounts that often suspend the drum(s) in vibratory compactors or asphalt rollers. The goal of the modeling is to predict the overall performance of the rubber mount system. The modeling includes calculations to 1) identify and quantify all predictable low-frequency loads on the rubber mounts during normal vehicle operations, 2) predict the steady-state high-frequency vibration response of the drum, rubber mounts, and vehicle frame during compaction operations, 3) predict the heat generation in the rubber mounts from their hysteretic damping, and 4) predict the fatigue life and life distribution of the rubber mounts. Some typical results of the modeling are provided along with some brief criteria to assess suspension performance. Other, unpredictable suspension loads are discussed but not modeled.
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