Craig J. Hoff

Design of a hybrid electric vehicle education program based on corporate needs

The needs of companies in the hybrid and electric vehicle business have been used to define a BS specialty in hybrid vehicles for electrical engineers at Kettering University. Two of the courses in this specialty are new courses whose development is sponsored by the US Department of Energy. Each course will be complemented by a laboratory that is also supported by the US Department of Energy. Both of the new courses will be developed into continuing education courses for delivery to company employees. The development of the new courses and laboratory will be completed at the end of 2011 and the continuing education versions will be available in 2012.

A model to estimate the effect of DC bus voltage on HEV powertrain efficiency

The efficiency of the electric drive system in a Hybrid Electric Vehicle plays a significant role in overall hybrid propulsion system efficiency and influences design choices for other mechanical components in the system. Increasing the DC bus voltage is thought to improve overall powertrain efficiency. In this paper, models are developed to predict the effect of DC bus voltage on the power loss in a PWM inverter motor drive and a brushless DC electric machine. The models indicate that a higher bus voltage will improve powertrain efficiency in some, but not all, operating conditions.

Legacy Vehicle Fuel System Testing with Intermediate Ethanol Blends

The goal of this project is to make a high-level compatibility assessment of legacy vehicle fuel system components to intermediate blends of gasoline and ethanol, specifically focusing on vehicles produced in the mid-1990s. These vehicles were designed before ethanol was a common gasoline component; therefore, their tolerance to higher concentrations of ethanol is not certain. This research project compared the effects of two blends of ethanol fuel on legacy fuel system components. An ethanol gasoline blend of 10% by volume ethanol (E10) was used for the control group, and a 17% ethanol by volume (E17) blend was used for the test group. The fuel systems tested comprised a fuel sending unit with pump, a fuel rail and integrated pressure regulator, and the fuel injectors. These systems were assembled into test rigs and operated to simulate the exposure received while driving. Specifically, the fuel pumps were cycled off and on and the fuel injectors were cycled with varying pulse widths during endurance testing. The performance characteristics of the systems and components were measured and periodic physical inspections were conducted to determine whether E17 fuel would lead to unusual degradation due to material incompatibilities. The aging testing lasted a minimum of 1,000 hours, which nominally simulates about 25,000–30,000 miles of highway vehicle travel. Fuel system components from three common mid-1990s vintage vehicle models were studied. Parts were chosen for the following vehicle/engine families: 1995-6 Ford Taurus with 3.0L-V6-2V VIN U engine (without flex-fuel), 1993-6 General Motors 3.1L-V6-2V VIN M engine (various vehicle models), and 1995 Toyota Camry with 3.0L-V6-4V 1MZ-FE engine.

Early introduction of CAE tools enhances success in student design competitions

The Society of Automotive Engineers (SAE) formula car events are the premier competitions for automotive engineering students worldwide. Student teams from accredited engineering educational institutions are asked to design and build small open-wheel, formula-one style vehicles. Younger members on the teams (freshman and sophomores) are often asked to design parts for the vehicle, long before they have completed the necessary core engineering courses. At Kettering University early introduction of CAE tools in the curriculum has helped to enhance the students ability to compete. With a high level of motivation, the team members are able to leverage their basic understanding of engineering and engineering tools to perform engineering analysis and design at a much higher level than one would expect. The early exposure to CAE tools has resulted in a number of successes for the Kettering Formula Car team including a 6th placed finish (out of 140 vehicles) in the Formula SAE design event.

A Numerical Study on Combustion and Emissions in a Dual Fuel Directly Injected Engine Using Biogas and Diesel

A numerical study on the use of biogas and diesel in a dual-fueled directly-injected engine has been conducted. The objective of this study is to determine the effect of using biogas on engine performance, combustion, and emissions. The main fuel is biogas which is premixed with air in order to form a homogeneous mixture. The mixture is then compressed and ignited by injecting diesel fuel before TDC. The pilot fuel is expected to lead to multiple ignition points in the cylinder in order to achieve uniform combustion in the cylinder. The expected benefits are lower nitrogen oxides and soot compared to pure diesel combustion. Numerical simulations using CFD software were used to simulate fuel-air mixture, compression, fuel injection, combustion, and emissions. Different quantities of biogas and diesel were investigated to determine the optimum mixture ratio. Since biogas, which is natural gas produced from human waste, contains large quantities of carbon dioxide, the effect of carbon dioxide content in the fuel was investigated. The results of this study agree very well with results from other studies found in the literature.© 2014 ASME

Design, Modeling and Development of a Serial Hybrid Motorcycle with HCCI Engine

This paper discusses the design, modeling, and development of small motorcycle equipped with a HCCI engine in an series hybrid configuration. A mathematical model was developed using MATLAB/Simulink and used to size the powertrain components and to predict fuel economy. A conventional 125 cc spark ignition engine was modified to run in HCCI combustion mode and integrated into a prototype vehicle. Dual-fuel and external EGR strategies were used to upgrade the engine speed and torque capabilities of the engine to meet the requirements of the powertrain. An electrical generator, hub-motor, battery pack and other power electronics devices were used to form the electrical system for the vehicle. The advantages of the proposed design compared to the original motorcycle with SI engine and CVT transmission are: 1) a reduction in noxious emissions due to the HCCI combustion, and 2) higher fuel economy in city driving because of the HCCI engine and series hybrid powertrain. Fuel economy was measured by driving the motorcycle on a chassis dynamometer using a sequence of ECE-40 driving cycles. The overall fuel economy was measured to be 73.7km/L which represents a 139.3% increase in fuel economy over the baseline vehicle.

Evaluating Impact Attenuator Performance for a Formula SAE Vehicle

Formula SAE® is one of several student design competitions organized by SAE International. In the Formula SAE events undergraduate and graduate students are required to conceive, design, fabricate and compete with a small, formula-style, race car. Formula SAE safety rules dictate a 7 m/s (or approximately 15.65 mph) frontal crash test for nose mounted impact attenuators. These rules are outlined in section B3.21 of the Formula SAE rule book. Development and testing methods of these energy absorbing devices have varied widely among teams. This paper uses real world crash sled results to research methods for predicting the performance of aluminum honeycomb impact attenuators that will comply with the Formula SAE standards. However, the resulting models used to predict attenuator performance may also have a variety of useful applications outside of Formula SAE. In this paper, various energy absorbers were mounted to a free rolling trolley sitting on top of a crash sled. The sled was launched so that the trolley with the attached attenuator was allowed to strike a rigid barrier. This resulted in a sudden deceleration measured by accelerometers attached to the trolley. The resulting deceleration from each impact attenuator was then correlated to predicted pulses from theoretical calculations. The lessons learned from extensive testing will be discussed including comparisons between size, shapes, and material properties of energy absorption devices. Additionally, a final theory will be presented describing the ideal way to predict impact attenuator performance. Ultimately it will be shown that, given a known geometry, material properties, and safety factor, the behavior of an impact attenuator can be predicted accurately enough that testing will only be needed as verification. This study will ultimately benefit all Formula SAE® teams, as it will help speed up development time and cut costs, while providing a proven method for creating attenuators that will perform to SAE standards.

Modeling of a Fuel Cell Hybrid Electric Vehicle

This paper explains the method by which a small “Neighborhood” fuel cell hybrid electric vehicle (FCHEV) was modeled using Matlab/Simulink and validated using National Instruments Data Acquisition equipment and a chassis dynamometer. The vehicle is a modified four-passenger Global Electric Motorcar (GEM), which was designed for city or neighborhood operation where maximum speed limits do not exceed 35 mph. The stock 72-Volt shunt wound GE motor is powered by six 12-Volt Trojan lead-acid batteries. The vehicle was converted to a FCHEV by integrating a Ballard Nexa™ fuel cell module and a Spectrodyne Systems DC-DC converter. These devices act as a constant current range extending supplemental power source. The goals of the creation of the model include predicting motor and battery performance while driving under transient conditions and predicting the range of the vehicle while using one or several fuel cell stacks.Copyright