Display:

Results

Viewing 271 to 300 of 341
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
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
2016-01-0845
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
2016-01-0393
Kevin P. Barbash, William V. Mars
Abstract We demonstrate here an accounting of damage accrual under road loads for a filled natural rubber bushing. The accounting is useful to developers who wish to avoid the typical risks in development programs: either the risk of premature failure, or of costly overdesign. The accounting begins with characterization of the elastomer to quantify governing behaviors: stress-strain response, fatigue crack growth rate, crack precursor size, and strain crystallization. Finite Element Analysis is used to construct a nonlinear mapping between loads and strain components within each element. Multiaxial, variable amplitude strain histories are computed from road loads. Damage accrues in this reckoning via the growth of cracks. Crack growth is calculated via integration of a rate law from an initial size to a size marking end-of-life.
2016-04-05
Technical Paper
2016-01-0391
Tanmay Sushant Santra, Vikas Kumar Agarwal, Mihir Bhambri
This paper depict the difference in the endurance factor of safety with usage of static and quasi static FE analysis and corrective measures take to solve the problem. The importance of the dynamic loading and subsequent effect of it on the multi axial fatigue analysis. Considering the modern trend prevailing among the vehicle manufacturers and specifically talking about two wheeler industry, it is clear that while the engine remains the same but the frame is changed to cater the market with new models to cut down on the development time. Initially the crankcase was designed for a double cradle frame where the crankcase was mounted on the frame. Later, the frame design was changed to single cradle where engine acts as a stress member link. This kind of arrangement makes the crankcase mountings participate in the chassis loads. Therefore, the crankcase mounting experiences road loads when the vehicle encounter the road irregularities.
2016-04-05
Technical Paper
2016-01-0448
Yuliang Yang, Yu Yang, Ying Sun, Zhihong Dong, Yunquan Zhang
Abstract To improve the vehicle NVH performance and reduce the vibration of the exhaust system, average driving DOF displacement (ADDOFD) and dynamic analysis are used to optimize hanger locations. Based on the finite element model and rigid-flexible coupling model, exhaust system analysis model was established. According to the finite element model of the exhaust system, the free-free modal analysis is carried out, and the position of the hanging point of the exhaust system is optimized by using the ADDOFD method. Furthermore, through the dynamics analysis, the force of each hanger to the body is calculated by the dynamic analysis, then verify the rationality of the hanging position. The combination of the two methods can effectively determine the better NVH performance of the exhaust system with hanger locations in the earlier vehicle development process.
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
Technical Paper
2016-01-0488
Takashi Izawa, Motohiko Koushima
Abstract In order to determine the seizure limit of the main bearings of passenger vehicles under actual operating conditions, evaluations were conducted in environments containing noise factors (Various factors which designer cannot adjust and which make function vary were defined as noise factors in this paper.) [1,2] It was shown that noise factors have an effect on seizure limit performance in relation to performance under ideal test conditions (test conditions in which no noise is present). In relation to oil properties, the results showed that a reduction in viscosity as a result of dilution affected seizure limit performance. In relation to the shape of the sliding sections of the test shaft, seizure limit performance declined in a shaft in which the central section was swollen (“convex shaft” below).
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
Technical Paper
2016-01-0473
Muthukumar Arunachalam, S Arunkumar, PraveenKumar Sampath, Abdul Haiyum, Beverly Katz
Abstract Current generation passenger vehicles are built with several electronic sensors and modules which are required for the functioning of passive safety systems. These sensors and modules are mounted on the vehicle body at locations chosen to meet safety functionality requirements. They are mounted on pillars or even directly on panels based on specific packaging requirements. The body panel or pillar poses local structural resonances and its dynamic behavior can directly affect the functioning of these sensors and modules. Hence a specific inertance performance level at the mounting locations is required for the proper functioning of those sensors and modules. Drive point modal frequency response function (FRF) analysis, at full vehicle model for the frequency range up to 1000 Hz, is performed using finite element method (FEM) and verified against the target level along with test correlation.
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
2016-01-0511
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
2016-01-0506
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
2016-01-0496
Leonardo Farfan-Cabrera, Ezequiel A. Gallardo
Abstract Debris are progressively generated just after wear occurred by the interaction of various mechanical elements inside the engines, steering gear boxes, transmissions, differentials, etc. Besides, debris could interfere with the normal operation of such components generating even more damage in other parts due to three-body abrasion. Hence, dynamic seals are susceptible to interact with very fine debris accumulated in the working lubes. Recently, owing to many test advantages, the micro-scale abrasion test has been extensively used to reproduce three-body abrasion in hard materials, coatings, polymers, etc., however, it has not been before employed for the wear assessment of elastomeric materials. This paper presents an adaptation of the micro-scale test method to study three-body abrasive behavior of an elastomeric dynamic seal (samples extracted from an automotive commercial Acrylonitrile-butadiene NBR rotary seal) under lubricated conditions.
2016-04-05
Technical Paper
2016-01-0839
Wenbin Yu, Wenming Yang, Balaji Mohan, Kunlin Tay, Feiyang Zhao, Yunpeng Zhang, Siawkiang Chou, Markus Kraft, Malcolm Andrew Alexander, Alfred Yong, Kwokhow Lou
Abstract In this study, the internal nozzle flow and macroscopic spray characteristics of a kind of wide distillation fuel (WDF) - kerosene were investigated both with numerical and experimental approaches. Simulation results indicate that compared with diesel fuel, kerosene cavitates more due to higher turbulent kinetic energy as a result of lower viscosity. The results from experiment indicate that under lower charge density, the spray penetration for kerosene is obviously shorter than that for diesel, especially for the lower injection pressure. This is because lower fuel viscosity results in a reduction in the size of the spray droplets, leading to lower momentum. However the spray angle of kerosene is larger compared with diesel due to stronger turbulence in the nozzle flow caused by increased cavitation for kerosene, which also accords well with the simulation results.
2016-04-05
Technical Paper
2016-01-0837
Per A. Risberg, Sara Alfredsson
Abstract A problem for the diesel engine that remains since its invention is injection nozzle hole fouling. More advanced injection systems and more complex fuels, now also including bio-components, have made the problem more intricate. Zinc and biodiesel have often been accused of being a big part of the problem, but is this really the case? In this study, nozzle fouling experiments were performed on a single cylinder engine. The experiments were divided in three parts, the first part studied the influence of zinc neodecanoate concentration on nozzle hole fouling, the second part studied the effect of neodecanoates of zinc, sodium, calcium, copper, and iron on fuel flow loss and in the last part it was examined how RME concentration in zinc neodecanoate contaminated petroleum diesel affected nozzle hole fouling propensity. After completed experiments, the nozzles were cut open and the deposits were analyzed in SEM and with EDX.
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
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
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.
2016-04-01
Standard
J2800_201604
This lab test procedure should be used when evaluating the combined corrosion and fatigue performance for a particular coating system, substrate, process and design. The test is intended to provide an A to B comparison of a proposed coil spring design versus an existing field validated coil spring when subjected to the combined effects of corrosion and fatigue. The corrosion mechanisms covered by this test include general, cosmetic and pitting corrosion. Fatigue testing covers the maximum design stress and/or stress range of the coil spring design (typically defined as excursion from jounce to rebound positions in a vehicle). The effects of gravel and heat are simulated by pre-conditioning the springs prior to fatigue testing. Time dependant corrosion mechanisms such as stress corrosion cracking are not addressed with this test.
Viewing 271 to 300 of 341

Filter

Subtopics