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Viewing 1 to 30 of 396
2017-03-28
Technical Paper
2017-01-0801
Keith Vertin, Brent Schuchmann, William Studzinski, Richard S. Davis, Thomas G. Leone, James E. Anderson, Asim Iqbal
Automakers are designing smaller displacement engines with higher power densities, to improve vehicle fuel economy while continuing to meet customer expectations for power and drivability. The specific power produced by the spark-ignited engine is constrained by knock and fuel octane ratings. Knock can lead to engine component damage and excessive exhaust gas temperatures that may cause thermal deactivation of catalytic convertors. Whereas the lowest octane rating is 87 AKI (anti-knock index) for regular gasoline at most service stations throughout the country, 85 AKI fuel is widely available at higher altitudes especially in the mountain west states. The objective of this study was to explore the effect of gasoline octane rating on the net power produced by modern light duty vehicles at high altitude conditions (1660m elevation). A chassis dynamometer test procedure was developed to measure absorbed wheel power at momentary and stabilized full power operation.
2017-03-28
Technical Paper
2017-01-0851
Hujie Pan, Min Xu, David Hung, Huijia Lv, Xue Dong, Tang-Wei Kuo, Ronald O. Grover, Scott E. Parrish
Increasing the injection pressure in SIDI engine is an efficient way to obtain finer droplets but it will also potentially cause spray impingement on the cylinder wall and piston. Consequently, the fuel film sticking on the wall can dramatically increase the soot emission of the engine especially in a cold start condition. On the other hand, ethanol is widely used as an alternative fuel in DI engine due to its sustainable nature and high octane number. In this study, the fuel film characteristics of single-plume ethanol impinging spray was investigated. The experiments were performed under ultra-low fuel/plate temperature to simulate the cold start condition in cold areas. A low temperature thermostatic bath combined with specially designed heat exchangers were used to achieve ultra-low temperature for both the impinging plate and the fuel. Laser induced fluorescence (LIF) technique was employed to measure the thickness of fuel film deposited on the impinging plate.
2017-03-28
Technical Paper
2017-01-1112
Jian yao, Li Chen, Ding zhao Jr, Chunhao Lee, Ying Huang, Yin Chengliang
The wedge clutch takes advantages of small actuation force/torque, space-saving and energy-saving. However, big challenge arises from the varying self-reinforced ratio due to the varying friction coefficient inevitably affected by temperature and wear. In order to improve the smoothness and synchronization time of the slipping process of the wedge clutch, this paper proposes a self-tuning PID controller based on Lyapunov principle. A new Lyapunov function is developed for the wedge clutch system. Simulation results show that the self-tuning PID obtains much less error than the conventional PID with fixed gains. Moreover, the self-tuning PID is more adaptable to the variation of the friction coefficient for the error is about 1/5 of the conventional PID.
2017-03-28
Technical Paper
2017-01-1534
Nina Tortosa, David Schroeck, Tony Nagle, Guy Flynt
The General Motors Reduced Scale Wind Tunnel Facility, which came into operation in the fall of 2015, is a new state-of-the-art scale model aerodynamic test facility that expands GM’s test capabilities. The new facility also increases GM’s aerodynamic testing through-put and provides the resources needed to achieve the growing demand for higher fuel economy requirements for next generation vehicles. The wind tunnel was designed for a nominal model scale of 40%. The nozzle and test section were sized to keep wind tunnel interference effects to a minimum. Flow quality and other wind tunnel performance parameters are on par with or better than the latest industry standards. A 5-belt system with a long center belt and boundary layer suction and blowing system are used to model underbody flow conditions. An overhead probe traverse system is installed in the test section along with a Model Positioning Robot used to move the model in an out of the test section.
2017-01-10
Technical Paper
2017-26-0108
MM Hashim
Abstract Interior permanent magnet machines are being widely used in hybrid vehicles owing to their compact size and high power density. Vehicle level application requires the motor to operate at high speed beyond the base speed of the motor. This is accomplished through flux weakening control. Nonfunctioning of inverter switches and/or gate driver circuit during flux weakening could give rise to a potential fault scenario called Un-Controlled Generation (UCG). This paper gives a detailed background of UCG and its impact on the high voltage and propulsion systems. In further sections the details related to modelling and analysis of UCG will be discussed. Finally, the paper will conclude with simulation results and comparison of the results with motor dynamometer test data.
2016-12-01
Article
Delphi rolls out its next-gen automated-driving technology platform, called CSLP, due for production by 2019.
2016-11-29
Article
While Donald Trump was blasting China for allegedly taking U.S. jobs, GM was quietly importing new China-made vehicles into the U.S.
2016-11-15
Article
At least for this moment, all is right with the world as Mercedes-Benz reinstates a new-age version of its iconic inline six-cylinder engine.
2016-11-07
Article
The Administration recently announced details of the expanded network of EV charging stations across nearly 25,000 mi (40,233 km) of highways in 35 U.S. states and the District of Columbia.
2016-10-24
Article
The key to engineering greatness is the willingness to take intelligent risks—both reputational and risks with the product, says one of the industry's greatest "product guys."
2016-09-22
Article
GM has taken a lesson from Tesla's Autopilot driver engagement problems and its new Super Cruise driving system will be different.
2016-09-16
Article
Advanced tire-simulation modeling allows tire development to keep pace with accelerated vehicle development cycles.
2016-08-01
Article
For 2016, the fourth year of its annual Enlighten Awards that acknowledge the best innovations in vehicle weight reduction, Altair named GM’s 2016 Cadillac CT6 as the winner in the Full-Vehicle category and ContiTech’s polyamide rear-axle transmission crossbeam is the winner in the Enlighten Awards’ Module category.
2016-07-17
Article
In concert with partner AK Steel, NanoSteel has finally brought its new sheet steel to the production threshold as the industry gobbles high-strength, lighter weight alloys at an increasing rate.
2016-06-30
Article
Vehicle-to-vehicle, or V2V communication could be the biggest safety boon since seatbelts.
2016-06-21
Article
Disruption is one thing, but another Tesla controversy helps explain why many tech companies know better than to try to take over the auto business.
2016-06-14
Article
BWI Group believes its second-generation Magneto Rheological (MR) powertrain mount helps meet downsized-powertrain NVH challenges.
2016-05-25
Article
The auto industry's crusade to reduce vehicle weight is creating clever new manufacturing techniques.
2016-05-19
Article
General Motors intends to transform materials-joining technology with a new multi-patented process for spot-welding steel to aluminum
2016-05-15
Article
With the first-generation Honda Ridgeline, buyers weren't ready for a unibody pickup with odd styling. For the 2017 model, the design is normal—and unibody refinement might be a concept whose time has come.
2016-04-12
Article
Nautilus Engineering: novel new engine design solves longstanding HCCI engine-development hurdles.
2016-04-11
Article
Automakers are increasingly employing digital crash test dummies made of zeroes and ones to take the big hits in virtual vehicles.
2016-04-05
Technical Paper
2016-01-0463
Juan Sierra, Camilo Cruz, Luis Munoz, Santiago Avila, Elkin Espitia, Jaime Rodriguez
Abstract Brake systems are strongly related with safety of vehicles. Therefore a reliable design of the brake system is critical as vehicles operate in a wide range of environmental conditions, fulfilling different security requirements. Particularly, countries with mountainous geography expose vehicles to aggressive variations in altitude and road grade. These variations affect the performance of the brake system. In order to study how these changes affect the brake system, two approaches were considered. The first approach was centered on the development of an analytical model for the longitudinal dynamics of the vehicle during braking maneuvers. This model was developed at system-level, considering the whole vehicle. This allowed the understanding of the relation between the braking force and the altitude and road grade, for different fixed deceleration requirement scenarios. The second approach was focused on the characterization of the vacuum servo operation.
2016-04-05
Technical Paper
2016-01-1205
Chih-Hung (Erik) Yen, Taeyoung Han, Shailendra Kaushik, Bahram Khalighi
Abstract As one of many pack-level battery simulation approaches developed within the General Motors-led Computer-Aided Engineering of Automotive Batteries (CAEBAT) Phase 1 project, the system approach treats the entire battery pack as a dynamic system which includes multiple engineering disciplines for simulation. It is the most efficient approach of all the CAEBAT battery pack-level approaches in terms of computational time and resources. This paper reports the application of the system approach for a 24-cell liquid-cooled prototype battery pack. It also summarizes the verification of the approach by comparing the simulation results with the measurement data. The results using the system approach are found to have a very good agreement with the measurements.
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.
2016-03-21
Article
The time is deliciously ripe for a Jeep pickup truck and the recent Comanche concept is an almost painfully perfect answer. So why could Jeep be waffling?
2016-03-18
Article
U.S. market sales for diesel-engine vehicles increased 4.2% in 2015, despite a drop in diesel car models available for sale as a result of VW's emissions scandal.
2016-03-18
Article
The XT5 now blatantly sets the new ride/handling “balance” benchmark, leaving BMW X5, Mercedes GLE and Lexus RX feeling roly-poly and heavy by comparison.
2016-03-15
Article
Cadillac has aggressively used light materials for its recently-launched new cars, but for the all-new C1 architecture underpinning the XT5 crossover, engineers stuck with steel—and still achieved a major weight reduction.
2016-02-19
Article
At the recent 2016 SAE Hybrid & EV Symposium in California, Automotive Engineering talked with Tim Grewe, GM’s Director of General Electrification, about the role of controls in the electrified vehicle space.
Viewing 1 to 30 of 396

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