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2016-06-15
Technical Paper
2016-01-1856
Hannes Allmaier, Günter Offner
Abstract Elastohydrodynamic (EHD)-simulation is a widely applied simulation technique that is used in a very diverse field of applications ranging from the study of vibroacoustics to the calculation of friction power losses in lubricated contacts. In particular, but not limited to, the automotive industry, technical advances and new requirements put current EHD simulation methodology under test. Ongoing trends like downsizing, downspeeding, start-stop and the continuing demand for increasing fuel efficiency impose new demands and challenges also on the simulation methodology. Increasing computational capabilities enable new simulation opportunities on the other hand. In the following, an overview is given on the current state of the art and today’s challenges for the elastohydrodynamic simulation of journal bearings and their wide range of applications from highly loaded main bearings supporting the crank shaft in the ICE to high speed turbocharger bearings.
2016-04-05
Technical Paper
2016-01-1092
Gabriela Achtenova, Jiri Pakosta
Abstract In the laboratories of CTU in Prague, an inertia test stand was recently built for endurance tests of the internal shift mechanisms of passenger cars. With regard to the instrumentation of the stand, it can be used also for determination of lost power of the not-loaded transmission. In this paper we present the values for the no-load losses measured during different conditions (temperature, shifted speed, speed of rotation) on the automotive mechanical gearbox for the transversal disposition of the drivetrain. For the further usage of the measured values is important to determine the proportion of the different sources of losses. We are mainly interested to identify the proportion of the churning losses and losses in the sealing, since these two losses remain the same, whatever the load of the gearbox will be. The losses of bearings on input and secondary shaft were calculated with the tool available from SKF.
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
Technical Paper
2016-01-1130
Mike Johns, Heinz Kamping, Kristian Krueger, James Mynderse, Chris Riedel
Abstract Tapered roller bearings used to support pinion and differential gears in automotive drive axles perform best with accurate assembled preload. One of the most common high volume production assembly methods relies on bearing friction to adjust preload; however torque is an indirect measure of load, can be influenced by the raceway condition, and is difficult to control. A new method to measure preload utilizes frequency response to estimate axial preload from system stiffness. The stiffness can be measured dynamically and an assembly method automated to set preload without the need for torque or dimensional measurements. By eliminating the need for a torque signal, the raceway conditions which contribute to setting torque do not contribute to the preload setting accuracy. This study demonstrates the effectiveness of using frequency response to measure stiffness and estimate preload.
2016-04-05
Technical Paper
2016-01-0873
Saeed Jahangirian, Aleksandra Egelja, Huiying Li
Abstract Demands for higher power engines have led to higher pressures in fuel injectors. Internal nozzle flow plays a critical role in the near nozzle flow and subsequent spray pattern. The internal flow becomes more difficult to model when the injector pressure and internal shape make it more prone to cavitation. Two Bosch injectors, proposed for experimental and computational studies under the Engine Combustion Network (namely “Spray C” and “Spray D”) are modeled in the computational fluid dynamics code ANSYS Fluent. Both injectors operate with n-dodecane as fuel at 150 MPa inlet pressures. The computational model includes cavitation effects to characterize any cavitating regions. Including compressibility of both liquid and vapor is found to be critical. Also, due to high velocity gradients and stresses in the nozzle, turbulent viscous energy dissipation is considered along with pressure work resulting from significant pressure changes in the injector.
2016-04-05
Technical Paper
2016-01-0845
Michele Bardi, Gilles Bruneaux, Louis-Marie Malbec
The Engine Combustion Network (ECN) has become a leading group concerning the experimental and computational analysis of engine combustion phenomena. In order to establish a coherent database for model validation, all the institutions participating in the experimental effort carry out tests at well-defined boundary conditions and using wellcharacterized hardware. In this framework, the reference Spray A injectors have produced different results even when tested in the same facility, highlighting that the nozzle employed and its fouling are important parameters to be accounted for. On the other hand, the number of the available Spray A injectors became an issue, due to the increasing number of research centers and simultaneous experiments taking place in the ECN community. The present work has a double aim: on the one hand, to seek for an appropriate methodology to “validate” new injectors for ECN experiments and to provide new hardware for the ECN community.
2016-04-05
Journal Article
2016-01-0851
Alexander Nygaard, Mireia Altimira, Lisa Prahl Wittberg, Laszlo Fuchs
Abstract It has been observed that intermittent injection leads to improved spray characteristics in terms of mixing and gas entrainment. Although some experimental work has been carried out in the past, the disintegration mechanisms that govern the breakup of intermittent jets remain unknown. In this paper we have carried out a systematic numerical analysis of the breakup of pulsated jets under different injection conditions. More specifically, the duty cycle (share of active injection during one cycle) is varied, while the total cycle time is kept constant. The advection of the liquid phase is handled through the Volume of Fluid approach and, in order to provide an accurate, yet computationally acceptable, resolution of the turbulent structures, the implicit Large Eddy Simulation has been adopted. The results show that the primary disintegration results from a combination of stretching, collision and aerodynamic interaction effects.
2016-04-05
Technical Paper
2016-01-0860
Fredrik R. Westlye, Michele Battistoni, Scott A. Skeen, Julien Manin, Lyle M. Pickett, Anders Ivarsson
Abstract This work investigates the effects of cavitation on spray characteristics by comparing measurements of liquid and vapor penetration as well as ignition delay and lift-off length. A smoothed-inlet, converging nozzle (nominal KS1.5) was compared to a sharp-edged nozzle (nominal K0) in a constant-volume combustion vessel under thermodynamic conditions consistent with modern compression ignition engines. Within the near-nozzle region, the K0 nozzle displayed larger radial dispersion of the liquid as compared to the KS1.5 nozzle, and shorter axial liquid penetration. Moving downstream, the KS1.5 jet growth rate increased, eventually reaching a growth rate similar to the K0 nozzle while maintaining a smaller radial width. The increasing spreading angle in the far field creates a virtual origin, or mixing offset, several millimeters downstream for the KS1.5 nozzle.
2016-04-05
Technical Paper
2016-01-1025
Daniela Cempirkova, Rostislav Hadas, Lukáš Matějovský, Rolf Sauerstein, Matthias Ruh
Abstract As emission regulations tighten across various regions of the world there is a growing trend in the use of alternative fuels such as Ethanol being blended with gasoline. A notable case of Ethanol usage is found in South America with the widespread use of E100, which has no gasoline content and can often contain up to 10% water. Engine oil contamination by fuel is of major concern and under certain conditions can have negative effects on the durability of turbocharger components which come into contact with contaminated oil, particularly sliding bearings, but also compressor stage through crankcase ventilation system fed gas. The manner in which this effect takes hold can cause a decrease in the lubrication properties and increase in corrosiveness of the engine oil.
2016-04-05
Technical Paper
2016-01-1348
Kenichi Higuchi, Fumihiko Toyoda, Hirohito Terashima, Shinji Ikeda, Eitaku Nobuyama
Abstract 1 There are two design challenges of the flow path switching valve in a three-stage variable discharge oil pump. The first is to obtain the required discharge pressure characteristics and the other is to prevent hydraulic vibration. Therefore, we established technologies to determine the shape of the valve and the valve housing that resolve these two challenges. The technology to obtain the required discharge pressure characteristics solves equations that are statically true, such as the equations for the equilibrium of forces and hydraulic orifice. The hydraulic vibration control technology derives a differential equation that takes transient behavior, including oil elasticity and inertia, into account first. Then, the derived equations are converted to a transfer function that indicates the valve behavior according to the input of oil pressure changes. And then the stability criterion is applied to judge whether hydraulic vibration occurs or not.
2016-04-05
Technical Paper
2016-01-1349
Siddharth Bhupendra Unadkat, Suhas Kangde, Mahalingesh Burkul, Mahesh Badireddy
Abstract In the current scenario, the major thrust is to simulate the customer usage pattern and lab test using virtual simulation methods. Going ahead, prime importance will be to reduce the number of soft tool prototype for all tests which can be predicted in CAE. Automotive door slam test is significantly complex in terms of prediction through simulation. Current work focuses on simulating the slam event and deriving load histories at different mounting locations through dynamic analysis using LSDyna. These extracted load histories are applied to trimmed door Nastran model and modal transient analysis is performed to find the transient stress history. This approach has a significant advantage of less computation time and stress-convergence with Nastran for performing multiple design iterations compared to LSDyna. Good failure correlation is achieved with the test using this approach.
2016-04-05
Journal Article
2016-01-1344
Koushi Kumagai, Masaaki Kuwahara, Tsuyoshi Yasuki, Norimasa Koreishi
Abstract This paper describes the development of a fracture finite element (FE) model for laser screw welding (LSW) and validation of the model with experimental results. LSW was developed and introduced to production vehicles by Toyota Motor Corporation in 2013. LSW offers superb advantages such as increased productivity and short pitch welding. Although the authors had previously developed fracture FE models for conventional resistance spot welding (RSW), a fracture model for LSW has not been developed. To develop this fracture model, many comprehensive experiments were conducted. The results revealed that LSW had twice as many variations in fracture modes compared to RSW. Moreover, fracture mode bifurcations were also found to result from differences in clearance between welded plates. In order to analyze LSW fracture phenomena, detailed FE models using fine hexahedral elements were developed.
2016-04-05
Technical Paper
2016-01-1356
Can Li, Yadong Deng, Yuhua Xin
Abstract As a key component of airstream system equipped in the road sweeper, the structure of the suction nozzle determines its internal flow field distribution, which affects the dust-sucking efficiency to a great degree. This research is aiming to determine a better suction nozzle structure. Starting with an analysis of the one used in a certain type of road sweeper, the initial model of the suction nozzle is established, and the internal flow field is simulated with typical computational fluid dynamics (CFD) software named FLUENT. Based on the simulation results, the dust-sucking capability of the initial structure is evaluated from the aspects of pressure and velocity distribution. Furthermore, in order to explore the influence of different structural parameters on the flow field distribution within the suction nozzle, models with different cavity heights and shoulder angles are established, and Univariate Method is utilized to analyze the contrast models.
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.
2016-04-05
Technical Paper
2016-01-0107
Sjon Moore
Abstract Traditional methods of costing wire harnesses focus primarily on the material and labor costs for manufacturing the final product. Rarely are costs related to variation-based complexity considered and when they are they tend to be simple approximations at best. In reality, the additional costs of excessive variation resulting in large part counts (unique harness level part numbers) can have a significant impact on the final cost incurred by an organization, and is often difficult to account for making it impossible for an organization to optimize their design, and everything that goes into making and delivering a finished product. It's important that these costs first be understood and modeled, and second that the designs be optimized based on this model. This paper will discuss these complexity based costs, including common sources, how they can be modeled, and methods for optimizing designs to account for these costs.
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
2016-01-0281
Alaa El-Sharkawy, Dipan Arora, Abd El-Rahman Hekal, Amr Sami, Muhannad Hendy
Abstract In this paper, transient component temperatures for the vehicle under-hood and underbody are estimated. The main focus is on the component temperatures as a result of radiation from exhaust, convection by underbody or under-hood air and heat conduction through the components. The exhaust surface temperature is simulated as function of time and for various vehicle duty cycles such as city traffic, road load and grade driving conditions. At each time step the radiation flux to the surrounding component is estimated, heat addition or removal by convection is evaluated based on air flow, air temperature and component surface area. Simulation results for under-hood and underbody components are compared against vehicle test data. The comparison shows very good agreement between simulated and measured component temperatures under both steady state and transient conditions.
2016-04-05
Technical Paper
2016-01-0801
Dimitri Seboldt, David Lejsek, Marlene Wentsch, Marco Chiodi, Michael Bargende
Abstract CNG direct injection is a promising technology to promote the acceptance of natural gas engines. Among the beneficial properties of CNG, like reduced pollutants and CO2 emissions, the direct injection contributes to a higher volumetric efficiency and thus to a better driveability, one of the most limiting drawbacks of today’s CNG vehicles. But such a combustion concept increases the demands on the injection system and mixture formation. Among other things it requires a much higher flow rate at low injection pressure. This can be only provided by an outward-opening nozzle due to its large cross-section. Nevertheless its hollow cone jet with a specific propagation behavior leads to an adverse fuel-air distribution especially at higher loads under scavenging conditions. This paper covers numerical and experimental analysis of CNG direct injection to understand its mixture formation.
2016-04-05
Journal Article
2016-01-0506
Daisuke Tomomatsu
Abstract This study developed technology for simultaneously welding heterogeneous resin tubes in order to weld and integrate resin tubes with two different specifications (low temperature and high temperature). The aim of integration was cost and weight reduction. The cost reduction due to reducing the number of parts exceeded the increase in material cost due to a change to resin materials. Base material fracture of the resin tubes was set as the breaking format condition, and the welding parameters of the joint part rotations and the friction time between the joint part and the resin tubes were specified as the weld strength judgment standard. In addition, the fused thickness determined by observing the cross-section after welding was specified as the weld quality judgment standard. The range over which weld boundary peeling does not occur and weld strength is manifest was clarified by controlling the welding parameters and the fused thickness.
2016-04-05
Journal Article
2016-01-0501
Seung Hoon Hong, Frank Yan, Shin-Jang Sung, Jwo Pan, Xuming Su, Peter Friedman
Abstract Failure mode and fatigue behavior of flow drill screw (FDS) joints in lap-shear specimens of aluminum 6082-T6 sheets with and without clearance hole are investigated based on experiments and a structural stress fatigue life estimation model. Lap-shear specimens with FDS joints were tested under cyclic loading conditions. Optical micrographs show that the failure modes of the FDS joints in specimens with and without clearance hole are quite similar under cyclic loading conditions. The fatigue lives of the FDS joints in specimens with clearance hole are longer than those of the FDS joints in specimens without clearance hole for the given load ranges under cyclic loading conditions. A structural stress fatigue life estimation model is adopted to estimate the fatigue lives of the FDS joints in lap-shear specimens under high-cycle loading conditions.
2016-04-05
Technical Paper
2016-01-0511
Na Qiu, Yunkai Gao, Jianguang Fang, Shanshan Wang
Abstract As a potential material for lightweight vehicle, polymethyl methacrylate (PMMA) has proven to perform well in optical behavior and weather resistance. However, the application in automotive glazing has seldom been studied. This paper investigates the defrost performance of PMMA rear window using both numerical and experimental methods. The finite element analysis (FEA) results were found to be in good agreement with the experimental data. Based on the validated finite element model, we further optimized the defrost efficiency by changing the arrangement of heating lines. The results demonstrated the frost layer on the vision-related region of PMMA rear window can melt within 30 minutes, which meets the requirement of defrost efficiency.
2016-04-05
Technical Paper
2016-01-0512
Chae-Hwan Hong
Polylactide (PLA), which is one of the most important biocompatible polyesters that are derived from annually renewable biomass such as corn and sugar beets, has attracted much attention for automotive parts application. The manufacturing method of PLA is the ring-opening polymerization of the dimeric cyclic ester of lactic acid, lactide. For the PLA composites including stereocomplexed with L- and D-PLA, we developed the unit processes such as fermentation, separation, lactide conversion, and polymerization. We investigated D-lactic acid fermentation with a view to obtaining the strains capable of producing D-lactic acid, and through catalyst screening test for polycondensation and depolymerization reactions, we got a new method which shortens the whole reaction time of lactide synthesis step. Poly(d-lactide) is obtained from the ring-opening polymerization of d-lactide. Also we investigated several catalysts and polymerization conditions.
2016-04-05
Technical Paper
2016-01-0513
Yohei Miki, Hisao Futamata, Masahiko Inoue, Masashi Takekoshi, Kohbun Yamada
Abstract Unexpected noise may occur around air intake manifold when the throttle valve is quickly opened. In order to solve this problem, mesh is often mounted into the air flow between the intake manifold and the throttle body. In this study the effect of mesh design on the noise reduction was investigated. Several designs of the mesh were tested with an actual automobile and the developed test equipment taking advantage of an intake manifold unit, and the noise attenuation was discussed with measuring the noise and observation of the mesh deformation. Based on those experiments, the mesh design for noise reduction was optimized. Furthermore integration of mesh and rubber gasket was examined. Finally, rubber mesh-gaskets which provide sealing and noise attenuation for air intake has been proposed in this study.
2016-04-05
Technical Paper
2016-01-0510
Praveen Mishra, Subramanian Ganeshan
Abstract An automobile outer rear view mirror (ORVM) is fixed at the front exterior of the vehicle for helping the driver see areas behind and sides of the vehicle which are outside of their peripheral vision. Mirror Scalp is the cover which protects the components inside from human and other environmental damage. Hence the scalp must be properly designed and fitted to the rest of the assembly so that it allows the safe functioning of the ORVM, which is an active safety device. During automatic car washing, sometimes the scalp may get removed due to the huge force exerted by the scrubber, if the scalp is not fitted properly. Mirror scalp is fitted to the rest of the ORVM through snap-fits. Snap-fits are the simplest, quickest and most cost effective method of assembling two parts. When designed properly, parts with they can be assembled and disassembled numerous times without any adverse effect on the assembly and hence are most environmentally friendly.
2016-04-05
Journal Article
2016-01-0515
Jee Young Youn, Seok Hwan Kim, Yong Sun (Steven) Jin
Abstract Impact resistance of plastic underbody parts was studied using simulated injection-molded specimen which can be tested according to different types of material used, injection molding variants like position and number of injection molding gates, and features of ribs. Material applied was glass fiber reinforced polyamide which can be used in underbody parts. Test was performed using several combinations of injection molding gates and rib types. From the test result, optimal design guide for plastic underbody parts was determined. Also, new high impact resistant plastic material made of glass fiber reinforced polyamide 66 (PA66) and polyamide 6 (PA6) alloy was developed and the material properties useful for CAE were determined. As a case study, oil pan and muffler housing were designed following the optimal design guide and CAE. And the reliability of the sample muffler housing designed was verified.
2016-04-05
Technical Paper
2016-01-0517
Kentaro Kimura, Ryoji Habuchi, Tetsuya Kono, Tadashi Mori, Kaname Arimizu
Abstract To reduce cabin noise and vehicle weight (for lower fuel consumption), a lightweight soundproofing cover was developed as a countermeasure to sources of noise, using the Biot theory (vibration propagation theory in poroelastic materials). This report also presents the results of its application to a metal belt-type continuously variable transmission (CVT) used in Toyota Motor Corporation’s 2.0L vehicles.
2016-04-05
Technical Paper
2016-01-1388
Baoke Huang, Jun Sun, Hu Wang, Xiaoyong Zhao, Qin Teng
Abstract In current design optimization of engine crankshaft bearing, only the crankshaft bearing is considered as the studying object. However, the corresponding relations of major structure dimensions exist between the crankshaft and the crankshaft bearing in engine, and there are the interaction effects between the crankshaft and the crankshaft bearing during the operation of engine. In this paper, the crankshaft-bearing system of a four-cylinder engine is considered as the studying object, the multi-objective design optimization of crankshaft bearing is developed. The crankshaft mass and the total frictional power loss of crankshaft bearings are selected as the objective functions in the design optimization of crankshaft bearing. The Particle Swarm Optimization algorithm is used in the optimization calculation. The optimization results are compared to the ones of original engine design and the single-objective design optimization of crankshaft bearing.
2016-04-05
Technical Paper
2016-01-1387
Subash Sudalaimuthu, Barry (Baizhong) Lin, Mohamed Sithik, Rajeev Sakunthala Rajendran
Abstract The advanced Optimization techniques help us in exploring the light weight architecture. This paper explains the process of designing a lightweight track bar bracket, which satisfies all durability performance targets. The mounting locations and load paths are critical factors that define the performance and help in the development of weight efficient structure. The process is to identify the appropriate bolt location through Design of Experiment (DOE) and topology based studies; followed by section and shape optimization that help to distribute material in a weight efficient manner across the structure. Load path study using topology optimization is performed to identify the load path for durability load cases. Further shape optimization is done using hyper study to determine the exact thickness of the webs and ribs. A significant weight reduction from the baseline structure is observed. This process may be applicable for all casting components.
2016-04-05
Technical Paper
2016-01-1381
Jiaqi Li, Jimin Ni, Xiuyong Shi
Abstract Sealing system is an important subsystem of modern high-performance engine. Sealing system reliability directly affects the engine operating conditions. Cylinder head gaskets(CHG) sealing system is of the most importance to the engine sealing system, which is not only responsible for sealing chamber, the cooling fluid and lubricating oil passage, for preventing gas leakage, water leakage and oil leakage, but also responsible for force transferring between cylinder head and cylinder body. Basing on nonlinear solution method, the sealing performance of multi-layer-steel cylinder head gaskets to a gasoline engine is studied with the finite element software ABAQUS. The deformations of the cylinder liners and engine block are also considered.
2016-04-05
Technical Paper
2016-01-1397
Charles Yuan, Erik Kane, Abid Rahman
Abstract New seal cross-section development is a very tedious and time consuming process if conventional analysis methods are used, as it is very difficult to predict the dimensions of the seal that will satisfy the sealing performance targets. In this study, a generic cross-section is defined and the design constraints are specified. Isight then runs the FEA model, utilizing a custom python script for post-processing. Isight then updates the dimensions of the seal and continues running analyses. Isight was run using two different design exploration techniques. The first was a design of experiments (DOE) to discover how the seal’s response varies with its dimensions. Then, after the analyst examined the results, Isight was run in optimization mode focusing on feasible design areas as determined from the DOE.
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