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Experimental Evaluation of Steady State Performance of an Automotive Electric Supercharger

Università Degli Studi di Genova-Silvia Marelli, Vittorio Usai
  • Technical Paper
  • 2020-37-0008
To be published on 2020-06-23 by SAE International in United States
Nowadays, the electric supercharger for turbocharged downsized automotive engines is mainly used to improve torque at low engine speeds in order to obtain an improvement of the time to boost. These components are usually designed to fill the gap in terms of torque in transient operation caused by the main turbocharger with reference to the typical turbo lag issues. An advanced solution of the engine boosting system was taken into account, considering the adoption of an e-booster system coupled to a waste-gated turbocharger, typically adopted alone in order to provide a reduced turbo-lag, i.e. an optimized transient response of the system. In the experimental activity described in this work, the maximum speed of the e-booster used is about 70000 rpm, the maximum pressure ratio is 1.5 and the maximum power required on the shaft is less than 4 kW. The compressor unit have to be maintained in the idle condition in order to avoid excessive electric consumption and overheating problem when the boost given by this component is not required. In order to highlight the…
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Inverse Vibration Problem Used for the Characterization of the Damping Added by a Trim Foam on a Plate

CEVAA-Nicolas Merlette
CEVAA, LAUM-Meryem LE DEUNF
  • Technical Paper
  • 2020-01-1580
To be published on 2020-06-03 by SAE International in United States
Many solutions exist to insure the NVH comfort of ground and air vehicles, like heavy mass (bitumen pads), viscoelastic treatments and absorbing foams. The trim foam is an alternative to heavy solutions. To know the potential of the foam, a study of its capacity to damp vibration is done. A system, composed by a suspended plate, with a foam on it, is characterized in different cases of contact at the foam-plate interface (glued or not) and with different types of foam. An experimental test facility is developed to identify the global damping of the structure: a laser vibrometer measures the displacement field of the foam-plate structure, an inverse method is used to determine the structural parameters. By changing the contact at the interface, it is possible to identify the contribution of the friction forces to the global damping of the structure. Another type of damping is the viscoelastic damping due to the intrinsic characteristics of the trim foam. With the help of FEA, it is possible to understand the influence of the damping effect. The…
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Squeak&Rattle - New Equivalent Static Load (ESL) based on Dynamic Distortion in all Body Openings from both Test and Simulation

AFRY-Viktor Jönsson
CEVT China Euro Vehicle Technology-Jens Weber, Mohamed Zaben
  • Technical Paper
  • 2020-01-1556
To be published on 2020-06-03 by SAE International in United States
The body stiffness has a major impact on the Squeak&Rattle (S&R) performance of a car. Since the body structure of electrical/automated cars will differ clearly from traditional bodies, an enhanced requirement is needed to limit the distortion in the closure openings. The new requirement can be derived from a complete vehicle simulation using the deformation of the diagonals in the closure openings. This simulation includes different test tracks by using the dynamic road load data which can be obtained from a multi body simulation of a complete vehicle. Since the requirement needs to be applied early in the development only an untrimmed body model (BIG) is available, which can be used for a simplified static load. This paper shows a new approach of defining an equivalent static load (ESL), which considers both the reduction from a complete vehicle to a BIG and from a dynamic load to a static load. The approach is based on the comparison of the deformation in the diagonals of all closure openings between the dynamic simulation of a complete trimmed…
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Inter-Laboratory Characterization of Biot Parameters of Poro-Elsastic Materials for Automotive Applications

Autoneum Holding AG-Francesca Ronzio, Claudio Bertolini
Faurecia S.A.-Minh Tan Hoang, Ludovic Dejaeger
  • Technical Paper
  • 2020-01-1523
To be published on 2020-06-03 by SAE International in United States
Automotive suppliers provide multi-layer trims mainly made of porous materials. They have a real expertise on the characterization and the modeling of poro-elastic materials. A dozen parameters are used to characterize the acoustical and elastical behavior of such materials. The recent vibro-acoustic simulation tools enable to take into account this type of material but require the Biot parameters as input. Several characterization methods exist and the question of reproducibility and confidence in the parameters arises. A Round Robin test was conducted on three poro-elastic material with four laboratories. Compared to other Round Robin test on the characterization of acoustical and elastical parameters of porous material, this one is more specific since the four laboratories are familiar with automotive applications. Methods and results are compared and discussed in this work. Finally some guidelines are drawn to improve the confidence in the characterized parameters and to compare them under similar conditions possibly adapted to the final application.
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Investigation of the Effect of Tire Deformation on Open-Wheel Aerodynamics

Graz University of Technology-Philipp Eder, Cornelia Lex
U.A.S. Graz-Thomas Gerstorfer, Thomas Amhofer
  • Technical Paper
  • 2020-01-0546
To be published on 2020-04-14 by SAE International in United States
This paper introduces a finite element (FE) approach to determine tire deformation and its effect on open-wheeled racecar aerodynamics. In recent literature the tire deformation was measured optically using cameras during wind tunnel testing. Combined loads like accelerat-ing at corner exit are difficult to reproduce in wind tunnels and would require several camer-as to measure the tire deformation. In contrast, an FE approach is capable of determining the tire deformation in combined load states accurately and additionally provides the possibility to vary further parameters, for example, the coefficient of friction. The FE tire model was validated using stiffness measurements, contact patch measurements and steady-state cornering measurements on a flat belt tire test rig. The deformed shape of the FE model was used in a computational fluid dynamics (CFD) simulation. A sensitivity study was created to determine the effect of the tire deformation on aerodynamics for un-loaded, purely vertically loaded and combined vertical, lateral and longitudinal forces. In addition, the influence of these three tire deformations was investigated in a CFD study using a full vehicle…
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Use of Nitric Acid to Control the NO2:NOX Ratio within the Exhaust Composition Transient Operation Laboratory Exhaust Stream

Southwest Research Institute-Robert Henderson, Ryan Hartley, Cary Henry
  • Technical Paper
  • 2020-01-0371
To be published on 2020-04-14 by SAE International in United States
The Exhaust Composition Transient Operation LaboratoryTM (ECTO-LabTM) is a burner system developed at Southwest Research Institute (SwRI) for simulation of IC engine exhaust. The current system design requires metering and combustion of nitromethane in conjunction with the primary fuel source as the means of NOX generation. While this method affords highly tunable NOX concentrations even over transient cycles, no method is currently in place for dictating the speciation of nitric oxide (NO) and nitrogen dioxide (NO2) that constitute the NOX mixture. NOX generated through combustion of nitromethane is dominated by NO, and generally results in an NO2:NOX ratio of < 5 %. Generation of any appreciable quantities of NO2 is therefore dependent on an oxidation catalyst to oxidize a fraction of the NO to NO2. Presented within this manuscript is a method for precise control of the NO2:NOX ratio within the ECTO-Lab exhaust stream by using nitric acid as the NOX precursor molecule in lieu of nitromethane. While decomposition of nitromethane generates NO as the dominate component of the NOX mixture, nitric acid decomposition produces…
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Development and Demonstration of a Class 6 Range-Extended Electric Vehicle for Commercial Pickup and Delivery Operation

Cummins Inc.-John Kresse, Ke Li, Jesse Dalton
National Renewable Energy Laboratory-Matthew A. Jeffers, Eric Miller, Kenneth Kelly
  • Technical Paper
  • 2020-01-0848
To be published on 2020-04-14 by SAE International in United States
Range-extended hybrids are an attractive option for medium- and heavy-duty commercial vehicle fleets because they offer the efficiency of an electrified powertrain with the driving range of a conventional diesel powertrain. The vehicle essentially operates as if it was purely electric for most trips, while ensuring that all commercial routes can be completed in any weather conditions or geographic terrain. Fuel use and point-source emissions can be significantly reduced, and in some cases eliminated, as many shorter routes can be fully electrified with this architecture.Under a U.S. Department of Energy (DOE)-funded project for Medium- and Heavy-Duty Vehicle Powertrain Electrification, Cummins has developed a plug-in hybrid electric Class 6 truck with a range-extending engine designed for pickup and delivery application. The National Renewable Energy Laboratory (NREL) assisted by developing representative workday drive cycles for Class 6 operation and an adapted cycle to enable vehicle track testing. A novel, automated driving system was utilized by Southwest Research Institute (SwRI) to improve the repeatability of the track testing conducted to quantify vehicle energy consumption. Cummins used a drivetrain…
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Heavy Vehicles Kinematics of Automatic Emergency Braking Test Track Scenarios

NHTSA-Devin Elsasser
Transportation Research Center Inc.-M. Kamel Salaani, Christopher Boday
  • Technical Paper
  • 2020-01-0995
To be published on 2020-04-14 by SAE International in United States
This paper presents the test track scenario design and analysis used to estimate the performances of heavy vehicles equipped with forward collision warning and automatic emergency braking systems in rear-end crash scenarios. The first part of this design and analysis study was to develop parameters for brake inputs in test track scenarios simulating a driver that has insufficiently applied the brakes to avoid a rear-end collision. In the second part of this study, the deceleration limits imposed by heavy vehicles mechanics and brake systems are used to estimate automatic emergency braking performance benefits with respect to minimum stopping distance requirements set by Federal Motor Vehicle Safety Standards. The results of this study were used to complete the test track procedures and show that all heavy vehicles meeting regulatory stopping distance requirements have the braking capacity to demonstrate rear-end crash avoidance improvements in the developed tests.
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A Holistic Approach to Develop a Modern High-Power Density Diesel Engine to Meet Best-in-Class NVH Levels

Mahindra & Mahindra, Ltd.-Vikraman Vellandi, Prasad Namani, Rajkumar Bhagate, Madhu Chalumuru
  • Technical Paper
  • 2020-01-0406
To be published on 2020-04-14 by SAE International in United States
The ever-increasing customer expectations put a lot of pressure on car manufacturers to constantly reduce the noise, vibration, and harshness (NVH) levels. This paper presents the holistic approach used to achieve best-in-class NVH levels in a modern high-power density 1.5 lit 4-cylinder diesel engine. In order to define the NVH targets for the engine, global benchmark engines were analysed with similar cubic capacity, power density, number of cylinders and charging system. Moreover, a benchmark diesel engine (considered as best-in-class in NVH) was measured in a semi-anechoic chamber to define the engine-level NVH targets of the new engine. The architecture selection and design of all the critical components were done giving due consideration to NVH behaviour while keeping a check on the weight and cost. Extensive 1D crank-train simulations were carried out to ensure that the crankshaft torsional amplitude was contained less than the NVH limit of 0.1 degree for higher-order excitations. Similarly, the flywheel-end speed irregularity was confirmed to be within acceptable limits. A complete engine-level simulation was carried out to simulate the surface velocities…
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A Smart Measuring System for Vehicle Dynamics Testing

Politecnico di Torino-Enrico Galvagno, Stefano Mauro, Stefano Pastorelli, Antonio Tota
  • Technical Paper
  • 2020-01-1066
To be published on 2020-04-14 by SAE International in United States
A fast measurement of the car handling performance is highly desirable to easily compare and assess different car setup, e.g. tires size and supplier, suspension settings, etc. Instead of the expensive professional equipment normally used by car manufacturers for vehicle testing, the authors propose a low-cost solution that is nevertheless accurate enough for comparative evaluations. The paper presents a novel measuring system for vehicle dynamics analysis, which is based uniquely on the sensors embedded in a smartphone and therefore completely independent on the signals available through vehicle CAN bus. Data from tri-axial accelerometer, gyroscope, GPS and camera are jointly used to compute the typical quantities analyzed in vehicle dynamics applications. In addition to signals such as yaw rate, lateral and longitudinal acceleration, vehicle speed and trajectory, normally available when working with Inertial Measurement Units (IMU) equipped with GPS, in the presented application the steering wheel angle is also measured, without additional sensors. The latter signal, besides being important for identifying the maneuver imposed by the driver, enables the usage of Kalman filters based on dynamic…