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Viewing 271 to 300 of 108180
2010-04-12
Technical Paper
2010-01-0575
Gen Shibata, Tomonori Urushihara
An HCCI combustion has a low temperature heat release (LTHR) and a high temperature heat release (HTHR). During the LTHR period, fuel chemicals break down into radicals and small hydrocarbons, and they assist an initial reaction of HTHR. This is an important role of LTHR. On the contrary, LTHR has a negative aspect. In general, a heating value of LTHR changes depending on HCCI engine load due to the difference of the injected fuel quantity. The heating value of LTHR is low under low load condition, and the heating value of LTHR is high under high load condition. This leads to the changes of the starting crank angle of HTHR against engine load and it is a nuisance problem for the control of HCCI engine operation. Therefore, a fuel which exhibits the constant LTHR phasing against engine load would be preferable.
2010-04-12
Journal Article
2010-01-0574
Jonathan Etheridge, Sebastian Mosbach, Markus Kraft, Hao Wu, Nick Collings
A Stochastic Reactor Model (SRM) has been used to simulate the transition from Spark Ignition (SI) mode to Homogeneous Charge Compression Ignition (HCCI) mode in a four cylinder in-line four-stroke naturally aspirated direct injection SI engine with cam profile switching. The SRM is coupled with GT-Power, a one-dimensional engine simulation tool used for modelling engine breathing during the open valve portion of the engine cycle, enabling multi-cycle simulations. The model is initially calibrated in both modes using steady state data from SI and HCCI operation. The mode change is achieved by switching the cam profiles and phasing, resulting in a Negative Valve Overlap (NVO), opening the throttle, advancing the spark timing and reducing the fuel mass as well as utilising a pilot injection. Experimental data is presented along with the simulation results.
2010-04-12
Technical Paper
2010-01-0581
Rentaro Kuroki, Akira Kato, Eiichi Kamiyama, Daisaku Sawada
The potential of high efficiency zero-emission engines fueled by hydrogen, which is regarded as a promising form of energy for the future, is being researched. The argon circulated hydrogen engine [ 1 ] is one system theoretically capable of achieving both high efficiency and zero emissions, and its feasibility for use in vehicles has been studied. Specifically, tests were performed to verify the following issues. It was examined whether stable hydrogen combustion could be achieved under an atmosphere of argon and oxygen, which has a high specific heat ratio, and whether the substantial thermal efficiency improvement effect of the argon working gas could be achieved. An argon circulation system was also studied whereby steam, which is the combustion product of the hydrogen and oxygen emitted from the engine, is separated by condensation to enable the remaining argon to be re-used.
2010-04-12
Technical Paper
2010-01-0580
Richard Stone, Huayong Zhao, Lei Zhou
A single-cylinder Gasoline Direct Injection Engine (GDI) engine with a centrally mounted spray-guided injection system (150 bar fuel pressure) has been operated with stoichiometric and rich mixtures. The base fuel was 65% iso-octane and 35% toluene; hydrogen was aspirated into a plenum in the induction system, and its equivalence ratios were set to 0, 0.02, 0.05 and 0.1. Ignition timing sweeps were conducted for each operating point. Combustion was speeded up by adding hydrogen as expected. In consequence the MBT ignition advance was reduced, as were cycle-by-cycle variations in combustion. Adding hydrogen led to the expected reduction in IMEP as the engine was operated at a fixed manifold absolute pressure (MAP). An engine model has also been set up using WAVE. Particulate Matter (PM) emissions were measured with a Cambustion DMS500 particle sizer.
2010-04-12
Journal Article
2010-01-0579
Victor M. Salazar, Sebastian A. Kaiser
This paper examines the interaction of bulk flow and jet-induced fuel convection in an optically accessible hydrogen-fueled engine with direct injection. Planar laser-induced fluorescence (PLIF) of gaseous acetone as a fuel tracer was performed to obtain quantitative images of the hydrogen mole-fraction in the operating engine. With the engine motored, fuel was injected into inert bulk gas from a centrally located injector during the compression stroke. The injector had a single-hole nozzle with the jet angled at 50 degrees with respect to the vertical injector axis. Two parameters were varied in the experiments, injector orientation and tumble intensity, and for each of these, the injection timing was varied. Image series of the mean fuel mole-fraction between injection and near-TDC crank angles capture the mixture-formation process for each configuration and injection timing.
2010-04-12
Technical Paper
2010-01-0578
Yan Yan, Zhang Yu-Sheng, Chen Yong-Tian, Chen Zu-Di, Xiao Ge
Homogeneous charge compression ignition (HCCI) is considered as a clean and high effective combustion technology. Alternative fuel Dimethyl Ether(DME) has some problems in HCCI combustion mode, such as narrow stable conditions and higher unregulated emissions. In this research, a single cylinder diesel engine zs195 was applied to HCCI operation, methanol and DME were fueled to the engine by fuel injection system with an electric controlled port in dual fuel mode. Regulated DME and methanol proportions can significantly expand the stable HCCI operation and obtained over a broad speed and load region. The emission tests indicated that NOx and smoke emissions were overall very low under normal HCCI operation, while HC and CO emissions were much higher than conventional CI-engines. HC and CO emissions increased with methanol content but reduced with output power.
2010-04-12
Technical Paper
2010-01-0586
Avoki Michel Omekanda, Todd Geib, Dan Buehler, Kirk Wan, Lucille G. Lavan
Gasoline Direct Injection (GDi) system is a relatively new technology. In early implementations, its major components, i.e. high pressure fuel pump, injectors, and fuel rails, emit objectionable acoustic noise during normal operation. This paper will focus on making an objective comparison (assessment) of acoustic noise emitted by several cam-driven high pressure fuel pumps during their normal operation, especially at engine idle. Taguchi robust engineering methods will be used to conduct the robust assessment study of six GDi high-pressure pumps. A-weighted total sound pressure level (SPL), processed from two free-field microphones around each pump, will be used as the main function in the Taguchi design of experiments (DOE).
2010-04-12
Journal Article
2010-01-0585
Paul Whitaker, Yuan Shen, Christian Spanner, Heribert Fuchs, Apoorv Agarwal, Kevin Byrd
Gasoline turbocharged direct injection (GTDI) engines, such as EcoBoost™ from Ford, are becoming established as a high value technology solution to improve passenger car and light truck fuel economy. Due to their high specific performance and excellent low-speed torque, improved fuel economy can be realized due to downsizing and downspeeding without sacrificing performance and driveability while meeting the most stringent future emissions standards with an inexpensive three-way catalyst. A logical and synergistic extension of the EcoBoost™ strategy is the use of E85 (approximately 85% ethanol and 15% gasoline) for knock mitigation. Direct injection of E85 is very effective in suppressing knock due to ethanol's high heat of vaporization - which increases the charge cooling benefit of direct injection - and inherently high octane rating. As a result, higher boost levels can be achieved while maintaining optimal combustion phasing giving high thermal efficiency.
2010-04-12
Technical Paper
2010-01-0584
Atsushi Shimada, Takao Ishikawa, Shuichi Kajitani
Hydrogen produced from regenerative sources has the potential to be a sustainable substitute for fossil fuels. A hydrogen internal combustion engine has good combustion characteristics, such as higher flame propagation velocity, shorter quenching distance, and higher thermal conductivity compared with hydrocarbon fuel. However, storing hydrogen is problematic since the energy density is low. Hydrogen can be chemically stored as a hydrocarbon fuel. In particular, an organic hydride can easily generate hydrogen through use of a catalyst. Additionally, it has an advantage in hydrogen transportation due to its liquid form at room temperature and pressure. We examined the application of an organic hydride in a spark ignition (SI) engine. We used methylcyclohexane (MCH) as an organic hydride from which hydrogen and toluene (TOL) can be reformed. First, the theoretical thermal efficiency was examined when hydrogen and TOL were supplied to an SI engine.
2010-04-12
Journal Article
2010-01-0590
John E. Kirwan, Mark Shost, Gregory Roth, James Zizelman
Today turbo-diesel powertrains offering low fuel consumption and good low-end torque comprise a significant fraction of the light-duty vehicle market in Europe. Global CO₂ regulation and customer fuel prices are expected to continue providing pressure for powertrain fuel efficiency. However, regulated emissions for NO and particulate matter have the potential to further expand the incremental cost of diesel powertrain applications. Vehicle segments with the most cost sensitivity like compacts under 1400 kg weight look for alternatives to meet the CO₂ challenge but maintain an attractive customer offering. In this paper the concepts of downsizing and downspeeding gasoline engines are explored while meeting performance needs through increased BMEP to maintain good driveability and vehicle launch dynamics. A critical enabler for the solution is adoption of gasoline direct injection (GDi) fuel systems.
2010-04-12
Technical Paper
2010-01-0582
Sebastian Verhelst, Joachim Demuynck, Steven Martin, Michael Vermeir, Roger Sierens
Hydrogen-fueled internal combustion engines (H₂ICEs) are an affordable, practical and efficient technology to introduce the use of hydrogen as an energy carrier. They are practical as they offer fuel flexibility, furthermore the specific properties of hydrogen (wide flammability limits, high flame speeds) enable a dedicated H₂ICE to reach high efficiencies, bettering hydrocarbon-fueled ICEs and approaching fuel cell efficiencies. The easiest way to introduce H₂ICE vehicles is through converting engines to bi-fuel operation by mounting a port fuel injection (PFI) system for hydrogen. However, for naturally aspirated engines this implies a large power penalty due to loss in volumetric efficiency and occurrence of abnormal combustion. The present paper reports measurements on a single-cylinder hydrogen PFI engine equipped with an exhaust gas recirculation (EGR) system and a supercharging set-up.
2010-04-12
Technical Paper
2010-01-0589
Michele Kaiser, Uwe Krueger, Roderick Harris, Luke Cruff
Due to the rising costs of fuel and increasingly stringent regulations, auto makers are in need of technology to enable more fuel-efficient powertrain technologies to be introduced to the marketplace. Such powertrains must not sacrifice performance, safety or driver comfort. Today's engine and powertrain manufacturers must, therefore, do more with less by achieving acceptable vehicle performance while reducing fuel consumption. One effective method to achieve this is the extreme downsizing of current direct injection spark ignited (DISI) engines through the use of high levels of boosting and cooled exhaust gas recirculation (EGR). Key challenges to highly downsized gasoline engines are retarded combustion to prevent engine knocking and the necessity to operate at air/fuel ratios that are significantly richer than the stoichiometric ratio.
2010-04-12
Technical Paper
2010-01-0588
David B. Roth, Philip Keller, Michael Becker
It has been clearly demonstrated separately, that the application of both Dual Cam Phasers (DCP) and External Cooled EGR systems are highly beneficial to improving the efficiency of highly-boosted GDI engines. DCP systems can optimize the volumetric efficiency at WOT conditions, improve boost and transient response at low engine speeds, and provide internal EGR at low RPM part-load conditions. External cooled EGR has been demonstrated to dramatically improve the fuel consumption, lower turbine inlet temperature, and improve emissions at high power conditions. In previous investigations by the BorgWarner Engine Systems Group, we showed that full engine speed/load range EGR coverage can be obtained by combining High Pressure Loop and Low Pressure Loop external EGR systems with a DCP strategy.
2010-04-12
Technical Paper
2010-01-0587
Luke Cruff, Michele Kaiser, Steven Krause, Roderick Harris, Uwe Krueger, Matthew Williams
The Ethanol-Boosted Direct Injection (EBDI) demonstrator engine is a collaborative project led by Ricardo targeted at reducing the fuel consumption of a spark-ignited engine. This paper describes the design challenges to upgrade an existing engine architecture and the synergistic use of a combination of technologies that allows a significant reduction in fuel consumption and CO₂ emissions. Features include an extremely reduced displacement for the target vehicle, 180 bar cylinder pressure capability, cooled exhaust gas recirculation, advanced boosting concepts and direct injection. Precise harmonization of these individual technologies and control algorithms provide optimized operation on gasoline of varying octane and ethanol content.
2010-04-12
Technical Paper
2010-01-0415
Dongkon Lee, Myung Han Lee, Kang-Duck Ih, Moo-Sang Kim, Franck Perot, Minsuk Kim, David Freed
Acoustics comfort is a key point for the ground transportation market and in particular in the automotive area. A significant contributor to the noise levels in the cabin in the range 200Hz to 3000Hz is the HVAC (Heating, Ventilating, and Air Conditioning) system, consisting of sub-systems such as the air intake duct, thermal mixing unit, blower, ducts, and outlet vents. The noise produced by an HVAC system is mainly due to aeroacoustics mechanisms related to the flow fluctuations induced by the blower rotation. The structure borne noise related to the surface induced vibrations and to the noise transmission through the dash or plastic panels may also contribute but is not considered in this study. This study presents a digital approach for HVAC aeroacoustics noise predictions related to the ducts and outlet vents. In order to validate the numerical method flow and acoustics measurements are performed on production HVAC systems placed in an anechoic room.
2010-04-12
Technical Paper
2010-01-0377
Jianfeng Ma, Joshua David Summers, Paul Joseph, Avinash Kolla
In this paper, in support of developing an advanced non-pneumatic lunar tire, a dynamic interaction model between non-pneumatic tire and sand is presented using the Finite Element Method (FEM). This non-pneumatic tire is composed of three major components: a critical shear beam, two inextensible circumferential membranes, and deformable spokes. The non-pneumatic tire made of segmented cylinders is described in detail. The tire is treated as an elastic deformable body with the inertia effect is included. Lebanon sand found in New Hampshire is modeled as because of the availability of a complete set of material properties in the literature. The Drucker-Prager/Cap plasticity constitutive law with hardening is employed to model the sand. Numerical results show contact pressure distribution, distributions of various stresses and strains, deformation of non-pneumatic tire, and deformation of sand.
2010-04-12
Technical Paper
2010-01-0414
Avnish Gosain, Mugundaram Ravindran
One of the most common NVH refinement areas of a vehicle is the cabin booming noise. The current study discusses the improvement of the low frequency booming noise in the cabin of a small passenger car. The practice of reinforcing experimental evaluation results with the extensive use of computer aided engineering tools in the development process is presented in this paper. The structural changes executed in the vehicle, to reduce noise contribution, are iterated and optimized using simulation and validated using experimental analysis methods like operational modal analysis, linear frequency response functions and actual run-up measurements. Additionally, the interesting variation of the NVH characteristics of a vehicle due to the changeover from a 4-cylinder inline to a 3-cylinder inline powertrain, while inheriting the similar body structure, is discussed in this study.
2010-04-12
Journal Article
2010-01-0378
Xiaobo Yang
In this study, a full vehicle with advanced LMS comfort and durability tire (CDT) model was established with ADAMS software to predict the spindle loads of the vehicle under a severe proving ground rough road event. From a series of simulations with various design changes, the spindle loads sensitivities to those design changes were identified. The simulated results were also compared with the measured data and a good correlation was achieved.
2010-04-12
Technical Paper
2010-01-0417
Cristiana Delprete, Fabio Pregno, Carlo Rosso
In the powertrain technology, designers must be careful on oil pan design in order to obtain the best noise, vibration and harshness (NVH) performance. This is a great issue for the automotive design because they affect the passengers' comfort. In order to reduce vibration and radiated noise in powertrain assembly, oil pan is one of the most critical components. The high stiffness of the oil pan permits to move up the natural modes of the component and, as a consequence, reduce the sound emission of the component itself. In addition, the optimized shape of the component allows the increase of natural frequency values of the engine assembly. The aim of this study is the development of a methodology to increase the oil pan stiffness starting from a sketch of the component and adding material where it is needed. The methodology is tested on a series of different models: they have the same geometry but different materials.
2010-04-12
Journal Article
2010-01-0379
Guofei Chen, Todd Link, Ming Shi, Tau Tyan, Ruth Gao, Paul McKune
To improve the energy absorption capacity of front-end structures during a vehicle crash, a novel 12-sided cross-section was developed and tested. Computer-aided engineering (CAE) studies showed superior axial crash performance of the 12-sided component over more conventional cross-sections. When produced from advanced high strength steels (AHSS), the 12-sided cross-section offers opportunities for significant mass-savings for crash energy absorbing components such as front or rear rails and crush tips. In this study, physical crash tests and CAE modeling were conducted on tapered 12-sided samples fabricated from AHSS. The effects of crash trigger holes, different steel grades and bake hardening on crash behavior were examined. Crash sensitivity was also studied by using two different part fabrication methods and two crash test methods. The 12-sided components showed regular folding mode and excellent energy absorption capacity in axial crash tests.
2010-04-12
Technical Paper
2010-01-0416
Weiguo Zhang, S. T. Raveendra, Moohyung Lee, J Stuart Bolton
The identification of the propulsion noise of turbofan engines plays an important role in the design of low-noise aircraft. The noise generation mechanisms of a typical turbofan engine are very complicated and it is not practical, if not impossible, to identify these noise sources efficiently and accurately using numerical or experimental techniques alone. In addition, a major practical concern for the measurement of acoustic pressure inside the duct of a turbofan is the placement of microphones and their supporting frames which will change the flow conditions under normal operational conditions. The measurement of acoustic pressures on the surface of the duct using surface-mounted microphones eliminates this undesirable effect. In this paper, a generalized acoustical holography (GAH) method that is capable of estimating aeroacoustic sources using surface sound pressure is developed.
2010-04-12
Journal Article
2010-01-0380
Shun Yi Jin, William J. Altenhof
Quasi-static axial cutting of AA6061-T6 and T4 round extrusions were completed using a specially designed cutter with multiple blades. The round specimens had a length of 200 mm, a nominal outer diameter of 50.8 mm, and a wall thickness of 3.175 mm or 1.587 mm. Four different cutters, constructed from heat-treated 4140 steel, having 3, 4, 5 and 6 blades on each cutter with a nominal tip width of 1.0 mm were used to penetrate through the round extrusions. A clean cutting mode was observed for the AA6061-T6 and T4 extrusions with wall thickness of 3.175 mm with an almost constant steady state cutting force. A braided cutting mode was observed for extrusions with both tempers with wall thickness of 1.587 mm, which resulted in a slightly oscillating steady state cutting force. For all extrusions with a wall thickness of 3.175 mm, the steady state cutting force increased with an increase in the number of cutter blades.
2010-04-12
Technical Paper
2010-01-0419
Yan Fu, Zhenfei Zhan, Ren-Jye Yang
This paper presents an enhanced Bayesian based model validation method together with probabilistic principal component analysis (PPCA). The PPCA is employed to address multivariate correlation and to reduce the dimensionality of the multivariate functional responses. The Bayesian hypothesis testing is used to quantitatively assess the quality of a multivariate dynamic system. Unlike the previous approach, the differences between test and CAE results are used for dimension reduction though PPCA and then to assess the model validity. In addition, physics-based thresholds are defined and transformed to the PPCA space for Bayesian hypothesis testing. This new approach resolves some critical drawbacks of the previous method and provides desirable properties of a validation method, e.g., symmetry. A dynamic system with multiple functional responses is used to demonstrate this new approach.
2010-04-12
Journal Article
2010-01-0383
Garrett W Wood, Matthew B Panzer, Cameron R Bass, Barry S Myers
The biofidelity of the Hybrid III headform in impact is largely dependent on local head geometry and viscoelastic mechanical properties of its polymer skin. Accordingly, for accurate simulation of the ATD headform in computational models, a quantitative understanding of the mechanical properties of skin material is required at a variety of strain rates and strain amplitudes. The objective of this study was to characterize the head skin material of the Hybrid III test dummy for finite deformations and at moderate strain rates for blunt impact simulation using finite element models Head skin material from a single ATD was tested using uniaxial compression. A viscoelastic constitutive model with separable temporal and elastic responses was used to characterize the nonlinear and viscoelastic material behavior.
2010-04-12
Journal Article
2010-01-0418
Xiaoguang Yang, Oluremi Olatunbosun, Emmanuel Bolarinwa
The use of accurate tire material properties is a major requirement for conducting a successful tire analysis using finite element method (FEM). Obtaining these material properties however poses a major challenge for tire modelers and researchers due to the complex nature of tire material and associated proprietary protections of constituent material properties by tire manufactures. In view of this limitation, a simple and effective procedure for generating tire materials data used in tire finite element analysis (FEA) is presented in this paper. All the tire test specimens were extracted from a tire product based on special considerations such as specimen dimension and shape, test standard, precondition of specimen and test condition for cords. The required material properties of tire rubber component, including hyperelasticity and viscoelasticity were obtained using simple uni-axial tension test.
2010-04-12
Technical Paper
2010-01-0384
Aref M. A. Soliman
This paper deals with an investigation of the road roughness on the vehicle ride comfort using semi-active suspension system. A mathematical model of quarter vehicle for semi active suspension system is developed to evaluate vehicle ride comfort. The rolling resistance and power losses are also investigated. The power consumed in rolling resistance and power dissipation in suspension for passive and semi-active suspensions are evaluated. The obtained results showed that ride comfort increases as the road roughness is decreased. Comparisons between passive and semi-active suspensions systems in terms of ride performance and power dissipation are also discussed.
2010-04-12
Technical Paper
2010-01-0421
Greg Browne, Nicholas Krouglicof, Geoff Rideout
Mathematical modeling is widely used throughout any scientific industry when trying to predict the behavior of dynamic systems. Oftentimes it is desirable that these models be simple and efficient, while still delivering accurate data. This paper builds and examines an energy-based (bond graph) model of an automotive fuel delivery system and suggests which elements are required to produce a Proper Model. The Model Order Reduction Algorithm (MORA) provides a mechanism to quantitatively rank each element in the model and determine its contribution to the system dynamics. Utilizing this approach, a model is developed that retains 98% of the complete system energy from 12 of the most active of 25 elements. This model requires 46.6% less simulation time while continuing to provide an adequate prediction of the system response.
2010-04-12
Technical Paper
2010-01-0385
Xiaobin Ning, Bin Meng, Jian Ruan
It is known that for automotive semi-active suspension the damping of shock absorber shall be continuously adjustable. One approach for damping adjustment is via adjusting flow area of throttle valve of shock absorber using stepping motor. Throttle valve can be realized using electro-magnetic valve or any other type of driving valve. In order to be applied on semi-active suspension, the throttle valve is required to have high control precision, fast response speed, strong anti-pollution capability and etc.. In this paper a new type of digital valve is presented to control the flow area of shock absorber. The configuration is developed by the utilization of the two-motions-degree of freedom of a single spool. To solve the contradiction between the response speed and the quantitative accuracy which characterizes the previous valve of the same sort, a specially designed tracking program is adopted to the stepping motor control to smooth displacement output.
2010-04-12
Technical Paper
2010-01-0386
Jared Gragg, Jingzhou (James) Yang, James David Long
Digital human modeling and simulation allows a designer to test a product early in the design process. Accounting for variability in the human population which the product is intended for is difficult without developing physical prototypes and conducting population testing. Digital human modeling allows a designer to test a product without a physical prototype in a simulated environment using digital humans. Using digital humans, or manikins, of various sizes, a designer can test for variability in the human population before any physical prototype is needed. This paper proposes an optimization-based approach to determine the seat adjustment range in the interior cab design of a vehicle. Previous methods of cab design include population sampling and stochastic posture prediction. This paper places boundary anthropometric digital human models, a 95% male and a 5% female, in a 3D test environment.
2010-04-12
Technical Paper
2010-01-0405
David A. Wagner, Stephen Logan, Kangping Wang, Timothy Skszek
Finite element analysis (FEA) predictions of magnesium beams are compared to load versus displacement test measurements. The beams are made from AM60B die castings, AM30 extrusions and AZ31 sheet. The sheet and die cast beams are built up from two top hat sections joined with toughened epoxy adhesive and structural rivets. LS-DYNA material model MAT_124 predicts the magnesium behavior over a range of strain rates and accommodates different responses in tension and compression. Material test results and FEA experience set the strain to failure limits in the FEA predictions. The boundary conditions in the FEA models closely mimic the loading and constraint conditions in the component testing. Results from quasi-static four-point bend, quasi-static axial compression and high-speed axial compression tests of magnesium beams show the beam's behavior over a range of loadings and test rates. The magnesium beams exhibit significant material cracking and splitting in all the tests.
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