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Cold-Start WHTC and WHSC Testing Results on Multi-Cylinder Opposed-Piston Engine Demonstrating Low CO2 Emissions while Meeting BS-VI Emissions and Enabling Aftertreatment Downsizing

SAE International Journal of Advances and Current Practices in Mobility

Univ. of Michigan-Ann Arbor-Samrat Patil
Achates Power Inc-Abhishek Sahasrabudhe, Fabien Redon, David Johnson, Laurence Fromm, John Headley
  • Journal Article
  • 2019-26-0029
Published 2019-01-09 by SAE International in United States
Reducing the greenhouse emissions from on-road freight vehicles to meet the climate change mitigation objectives, has become a prime focus of regulatory authorities all over the world. Besides India, the United States, the European Union, Canada, Japan, and China have already established or planned heavy-duty vehicle efficiency regulations addressing CO2 and NOX emissions. In addition, Argentina, Brazil, Mexico, and South Korea are all in various stages of developing policies to improve the efficiency of their commercial vehicle fleets. For CO2 emissions reduction standards, the U.S. mandates 27% reduction by 2027, EU is calling for 15% reduction by 2025, China for 27% by 2019 over 2012 levels, and India is mandating 10%-15% reduction by 2021 for phase 2 of the new standard. There has also been considerable focus on further reduction in NOX emissions from current levels (0.2 g/hp-hr), to the proposed ultra-low NOx standards (0.02 g/hp-hr) in the U.S. for heavy duty engines by 2024.Given these planned and proposed regulatory standards being implemented around the globe, there have been substantial studies and publications focusing on…
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ERRATUM:The Effects of Temperature, Shear Stress, and Deposit Thickness on EGR Cooler Fouling Removal Mechanism - Part 2

SAE International Journal of Materials and Manufacturing

Hyunki Sul
Univ. of Michigan-Ann Arbor-Taehoon Han
  • Journal Article
  • 2016-01-0186.01
Published 2016-04-05 by SAE International in United States
ERRATUM: In the article Reference 24 should read as follows: 24. Han, T., Booth, A., Song, S., Styles, D., and Hoard, J., “Review and A Conceptual Model of Exhaust Gas Recirculation (EGR) Cooler Fouling Deposition and Removal Mechanism” Proceedings of the Int. Conf. on Heat Exchanger Fouling and Cleaning, 2015”
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Estimation of Secondary Mass Changes in Vehicle Design

SAE International Journal of Materials and Manufacturing

Univ. of Michigan-Ann Arbor-Donald E. Malen
Fka - Forschungsgesellschaft Kraftfahrwe-Roland Wohlecker
  • Journal Article
  • 2013-01-0655
Published 2013-04-08 by SAE International in United States
It is well known that an unplanned component mass increase during vehicle design creates a ripple effect of changes throughout the vehicle subsystems, which require resizing for the additional mass. This in turn, increases overall vehicle mass. And the opposite is true in vehicle mass reduction where subsystem resizing is necessary to account for an initial mass reduction enabled, for example, by a new technology. These secondary mass changes can be significant and must be considered in the mass budgeting process due to their importance to fuel consumption and greenhouse gas emission assessments. Secondary mass reduction may be modeled using subsystem mass influence coefficients-the incremental change in subsystem mass for a unit change in gross vehicle mass. This paper focuses on means to estimate influence coefficients using two methods: Analytical and Regression.
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Optical and Infrared In-Situ Measurements of EGR Cooler Fouling

Univ. of Michigan-Ann Arbor-Ashwin A. Salvi, John Hoard, Pavan Karthik Jagarlapudi, Theera Pornphaithoonsakun, Kevin Collao
Ford Motor Co.-Daniel J. Styles, Mehdi Abarham, Eric W. Curtis
Published 2013-04-08 by SAE International in United States
The use of exhaust gas recirculation (EGR) in internal combustion engines has significant impacts on combustion and emissions. EGR can be used to reduce in-cylinder NOx production, reduce emitted particulate matter, and enable advanced forms of combustion. To maximize the benefits of EGR, the exhaust gases are often cooled with on-engine liquid to gas heat exchangers. A common problem with this approach is the build-up of a fouling layer inside the heat exchanger due to thermophoresis and condensation, reducing the effectiveness of the heat exchanger in lowering gas temperatures.Literature has shown the effectiveness to initially drop rapidly and then approach steady state after a variable amount of time. The asymptotic behavior of the effectiveness has not been well explained. A range of theories have been proposed including fouling layer removal, changing fouling layer properties, and cessation of thermophoresis. In an effort to investigate this phenomenon, an EGR cooler visualization rig has been constructed. This rig incorporates an optically and infrared transparent access window, allowing for measurement of key deposit layer variables in-situ. These variables coupled…
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Safety Performance and Benefits of Heavy Truck Stability Control: Providing Insight into Compliance Evaluation

SAE International Journal of Commercial Vehicles

Univ. of Michigan-Ann Arbor-John Woodrooffe
Transportation Research Inc.-Daniel Blower
  • Journal Article
  • 2012-01-1906
Published 2012-09-24 by SAE International in United States
This paper contains an analysis of the potential safety benefits of electronic stability control (ESC) for single unit trucks and tractor semitrailers within the U.S. operating environment. It is based on research projects [1,2] which combined hardware-in-the-loop simulation and vehicle testing with the analysis of independent crash datasets using engineering and statistical techniques to estimate the probable safety benefits of stability control technologies for 5-axle tractor-semitrailer vehicles and single unit trucks. The characteristics of ESC-relevant crashes involving these two vehicle classes were found to be very different as were the control strategies needed for crash avoidance. Rollover was the dominant ESC relevant crash type for tractor semitrailers while loss of control was the dominant ESC relevant crash for straight trucks.The conventional approach for assessing the safety benefits of vehicle technologies is to analyze crash datasets containing data on the safety performance of vehicles equipped with the technology of interest. Because the deployment of ESC for large trucks is in its infancy, national crash databases do not yet have sufficient data that can be directly linked…
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An Analytical Load Distribution Solution for Bearings

Univ. of Michigan-Ann Arbor-Jaewon Lee, Jwo Pan
Chrysler Group LLC-Yung-Li Lee
Published 2012-04-16 by SAE International in United States
An analytical load distribution solution for calculation of the loads exerted by the rolling elements on the outer raceway in cylindrical roller bearings under radial loading is proposed in this paper. The loads exerted by the rolling elements are obtained based on an assumption that the profile of the maximum contact pressures of rolling elements resemble the profile of the contact pressure of the corresponding lumped cylinder. Based on this assumption, an analytical load distribution solution which gives the loads exerted by the rolling elements on the outer raceway is derived based on the non-conforming contact solution of Hertz and the conforming contact solution of Persson. These loads can be calculated from the analytical solution with the total applied load and the normalized contact pressure profile of the corresponding lumped cylinder. Two-dimensional finite element analysis was conducted to validate the proposed analytical solutions. The maximum pressure due to the maximum load of the rolling elements calculated from the analytical solution is within a few percents of the result from the two-dimensional finite element analysis.
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A Nonparametric Bootstrap Approach to Variable-size Local-domain Design Optimization and Computer Model Validation

SAE International Journal of Materials and Manufacturing

Univ. of Michigan-Ann Arbor-Michael Kokkolaras
Oakland Univ.-Dorin Drignei, Zissimos Mourelatos, Vijitashwa Pandey
  • Journal Article
  • 2012-01-0226
Published 2012-04-16 by SAE International in United States
Design optimization often relies on computational models, which are subjected to a validation process to ensure their accuracy. Because validation of computer models in the entire design space can be costly, a recent approach was proposed where design optimization and model validation were concurrently performed using a sequential approach with both fixed and variable-size local domains. The variable-size approach used parametric distributions such as Gaussian to quantify the variability in test data and model predictions, and a maximum likelihood estimation to calibrate the prediction model. Also, a parametric bootstrap method was used to size each local domain. In this article, we generalize the variable-size approach, by not assuming any distribution such as Gaussian. A nonparametric bootstrap methodology is instead used to size the local domains. We expect its generality to be useful in applications where distributional assumptions are difficult to verify, or not met at all. A heat conduction problem illustrates the proposed methodology.
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Effect of a Deformable Roller on Residual Stress Distribution for Elastic-Plastic Flat Plate Rolling under Plane Strain Conditions

SAE International Journal of Materials and Manufacturing

Univ. of Michigan-Ann Arbor-M. Y. Ali, Jwo Pan
  • Journal Article
  • 2012-01-0190
Published 2012-04-16 by SAE International in United States
In this paper, the differences of the residual stresses due to rolling in a finite elastic-plastic plate by rigid and elastic deformable rollers at very high rolling loads are investigated by two-dimensional plane strain finite element analyses using ABAQUS. In the finite element analyses, the rollers are modeled both as rigid and linear elastic, and have frictionless contact with the elastic-plastic finite plate. The plate material is modeled as an elastic-plastic power-law strain hardening material with a non-linear kinematic hardening rule for loading and unloading. Two new numerical schemes are developed to represent the elastic roller to model the indentation and rolling. The results of the contact pressure and subsurface stress distributions from the two numerical schemes are almost identical. For both roller models, the computational results show that the contact pressure and subsurface stress distributions in the elastic-plastic plate are similar for both indentation and rolling at high rolling loads with extensive plastic deformation. The computational results also indicate that the residual stresses after rolling are nearly the same for both roller models. The…
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Failure Modes of Friction Stir Spot Welds in Lap-Shear Specimens of Dissimilar Advanced High Strength Steels under Quasi-Static and Cyclic Loading Conditions

SAE International Journal of Materials and Manufacturing

Univ. of Michigan-Ann Arbor-Seung-Hoon Hong, Kulthida Sripichai, Chia-Siung Yu, Katherine Avery, Jwo Pan
Oak Ridge National Laboratory-Tsung-Yu Pan, Michael Santella
  • Journal Article
  • 2012-01-0479
Published 2012-04-16 by SAE International in United States
Failure modes of friction stir spot welds in lap-shear specimens of dissimilar high strength dual phase steel (DP780GA) and hot stamped boron steel (HSBS) sheets are investigated under quasi-static and cyclic loading conditions based on experimental observations. Optical micrographs of dissimilar DP780GA/HSBS friction stir spot welds made by a concave tool before and after failure are examined. The micrographs indicate that the failure modes of the welds under quasi-static and cyclic loading conditions are quite similar. The micrographs show that the DP780GA/HSBS welds mainly fail from cracks growing through the upper DP780GA sheets where the concave tool was plunged into during the welding process. Based on the observed failure modes, a kinked fatigue crack growth model is adopted to estimate fatigue lives. The fatigue life estimations are reasonably in agreement with the experimental results under low-cycle loading conditions but lower than the experimental results under high-cycle loading conditions.
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A Variable-Size Local Domain Approach to Computer Model Validation in Design Optimization

SAE International Journal of Materials and Manufacturing

Univ. of Michigan-Ann Arbor-Michael Kokkolaras
Oakland Univ.-Dorin Drignei, Zissimos Mourelatos, Jing Li, Grzegorz Koscik
  • Journal Article
  • 2011-01-0243
Published 2011-04-12 by SAE International in United States
A common approach to the validation of simulation models focuses on validation throughout the entire design space. A more recent methodology validates designs as they are generated during a simulation-based optimization process. The latter method relies on validating the simulation model in a sequence of local domains. To improve its computational efficiency, this paper proposes an iterative process, where the size and shape of local domains at the current step are determined from a parametric bootstrap methodology involving maximum likelihood estimators of unknown model parameters from the previous step. Validation is carried out in the local domain at each step. The iterative process continues until the local domain does not change from iteration to iteration during the optimization process ensuring that a converged design optimum has been obtained. The proposed methodology is illustrated using a thermal, one-dimensional, linear heat conduction problem in a solid slab with heat flux boundary conditions.
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