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The thermal comfort inside automotive cabin has been extensively studied for decades. Traditional CFD models provide accurate simulation results of the air temperature distributions inside cabins but at a relatively high computation cost. In order to reduce the computational cost while still providing reasonable accuracy in simulating the air temperature profile inside a mid-sized sedan cabin, this paper introduces a new simulation tool that utilizes a proper orthogonal decomposition (POD) method. The POD method, an interpolation technique, requires only one set of multiple CFD simulations to produce a set of “snapshots”. Later, any simulations that require CFD runs to solve algorithm equation sets can be simplified by using interpolation between the snapshots provided that the geometry of the cabin keeps the same. As a result, the computation time can be reduced to only a few minutes.

A newly designed and built Mobile Tire Testing Machine (MTTM) is described that has features for large and continuously variable camber and steering angles with minimum tire scrub. This equipment was used to examine tire properties for six passenger car tires. Of special interest were the tire characteristics at combinations of high slip and camber angle. It was found that camber stiffness decreases with increasing slip angle when the slip and camber angles are both positive, and at limit conditions in slip angle, cambering a tire has little effect on the lateral side force produced. When the slip angle is negative, and the camber angle is positive, preliminary data shows that a greater lateral force is produced when compared to operating at limit conditions in slip angle alone.

The Pride of Maryland is a single seat solar powered trans-continental race car designed and built by engineering students at the University of Maryland. The car competed in G.M. Sunrayce USA, placing third, and has gone on to compete in the World Solar Challenge. This paper outlines the three general areas of design and development for the solar vehicle: aerodynamic, electrical, and mechanical. An exercise in high efficiency, the Pride of Maryland has been extremely successful as both a race car and as an educational tool for training student engineers in “real world” problems.

This study examines the types of hydrogen leaks that can support combustion and the effects on stainless steel of long term hydrogen flame exposure. Experimental and analytical work is presented. Hydrogen diffusion flames on round burners were observed. Measurements included limits of quenching, blowoff, and piloted ignition for burners with diameters of 0.36 - 1.78 mm. Results are compared to measurements for methane and propane. A dimensionless crack parameter was identified to correlate the quenching limit measurements. Flow rates were 0.019 - 40 mg/s for hydrogen, 0.12 - 64 mg/s for methane, and 0.03 - 220 mg/s for propane. Hydrogen flames were found to be corrosive to 316 stainless steel tubing.

The University of Maryland team converted a model year 2000 Chevrolet Suburban to an ethanol-fueled hybrid-electric vehicle (HEV) and tied for first place overall in the 2000 FutureTruck competition. Competition goals include a two-thirds reduction of greenhouse gas (GHG) emissions, a reduction of exhaust emissions to meet California ultra-low emissions vehicle (ULEV) Tier II standards, and an increase in fuel economy. These goals must be met without compromising the performance, amenities, safety, or ease of manufacture of the stock Suburban. The University of Maryland FutureTruck, Proteus, addresses the competition goals with a powertrain consisting of a General Motors 3.8-L V6 engine, a 75-kW (100 hp) SatCon electric motor, and a 336-V battery pack. Additionally, Proteus incorporates several emissions-reducing and energy-saving modifications; an advanced control strategy that is implemented through use of an on-board computer and an innovative hybrid-electric drive train.

The potential for thermoelectric power generation via waste heat recovery onboard automobiles to displace alternators and/or provide additional charging to a hybrid vehicle battery pack has increased with recent advances in thermoelectric materials processing. A preliminary design/modeling study was performed to optimize waste heat recovery for power generation using a modified radiator incorporating thermoelectric modules. The optimization incorporates not only thermoelectric performance but also critical systems issues such as accessory power consumption, vehicle drag, and added system weight. Results indicate the effectiveness of the thermoelectric module is extremely sensitive to ambient heat rejection and to the operating temperature range of the thermoelectric device.

The University of Maryland FutureTruck Team has redesigned a 2002 Ford Explorer to function as a charge-sustaining parallel hybrid electric vehicle for the 2002-2003 FutureTruck competition. Dubbed the Excite, it is powered by a dedicated E85 3.0L V6 engine coupled to a 21.6 kW peak (10kW continuous), electric motor using a 144V NiMH battery pack. The philosophy behind the UMD plan is to use a smaller, lightweight, dedicated E85 engine in parallel with an electric motor to provide starting and mild assist capabilities. The engine provides similar power to the stock 4.0 L Explorer engine and the electric motor functions as a starter, an alternator, and assists the engine during high power demands. The combination of the two systems provides the Excite with engine-off-at-idle capability, increased efficiency and fuel economy, and decreased emissions while maintaining the utility of a stock SUV.

The control and analysis of magnetic bearings has been primarily based upon classical linear control theory. This approach does not allow for some important system complexities and nonlinearities to be taken into account. The resulting simplifications degrade the overall system performance. This paper investigates the use of a neural network to control a magnetic bearing flywheel energy storage system. A plant simulation is developed as well as a neural network emulator and controller.

AMBER (Active Magnetic Bearing Evaluation Routine) is a computer algorithm developed for the University of Maryland pancake magnetic bearing, which supports and controls a flywheel in a kinetic energy storage system. Because of the gap growth due to centrifugal forces at high speed, the bearing axial load capability degrades and the axial characteristics become critical in the bearing design. AMBER applies magnetic circuit theory, magnetic material saturation curves, coenergy theory, and finite permeance-based elements to solve the air gap flux density and coenergy over a series of incremental axial displacements. Differentiation of the coenergy of the magnetic field yields axial force and stiffness characteristics. An axial test machine is constructed to conduct experiments to verify the flux distribution and axial forces predicted by the model. User interaction with AMBER allows modification of the bearing geometry and composition to optimize future prototypes.

Chemically enhanced autoignition in a spark-ignited engine with a special design of piston geometry has been observed experimentally, in which the engine would operate stably without a spark, once it is started by spark ignition. Under this operation mode, the engine provides lower pollutant emissions including NOx. In this process, the intermediate species left from the previous cycle play a key role in the low temperature autoignition. The objective of this study is to determine the effect of some important radical and intermediate species, such as HO2, OH, and H2O2, on autoignition by a numerical modeling approach using a detailed chemical kinetic mechanism. The fuel studied is hydrogen. The effect of added HO2, OH and H2O2 on the characteristics of the autoignition of H2-air mixture is investigated. Chemically enhanced autoignition of H2-air in an internal combustion engine is also simulated.

Effects of boundary conditions on the computational simulation of time dependent flows is studied. In particular, the effect of various boundary conditions for the flow over a half circular cylinder which is known to exhibit periodic shedding under certain conditions is investigated. A type of convection boundary condition called the radiation boundary condition is demonstrated to eliminate the secondary frequency which contaminates the solution due to the partial reflection of the fluid structures at the exit plane. However, the boundary condition implementation comes at the additional cost of storing results corresponding to three time levels.

The Ranger Telerobotic Shuttle Experiment (RTSX) is a Space Shuttle-based flight experiment to demonstrate key telerobotic technologies for servicing assets in Earth orbit. The flight system will be teleoperated from onboard the Space Shuttle and from a ground control station at the NASA Johnson Space Center. The robot, along with supporting equipment and task elements, will be located in the Shuttle payload bay. A number of relevant servicing operations will be performed-including extravehicular activity (EVA) worksite setup, orbital replaceable unit (ORU) exchange, and other dexterous tasks. The program is underway toward an anticipated launch date in CY2002. This paper gives an overview of the RTSX mission, and describes several follow-on mission scenarios involving cooperative Ranger and EVA activities.

In low earth orbit satellite applications, spacecraft power is provided by photovoltaic cells and batteries. Unfortunately, use of batteries present difficulties due to their poor energy density, limited cycle lifetimes, reliability problems, and the difficulty in measuring the state of charge. Flywheel energy storage offers a viable alternative to overcome some of the limitations presented by batteries. FARE, Inc. has built a 50 Wh flywheel energy storage system. This system, called the Open Core Flywheel, is intended to be a prototype energy storage device for low earth orbit satellite applications. To date, the Open Core Flywheel has achieved a rotational speed of 26 krpm under digital control.

This manuscript presents a systematic approach for the design and development of a 403 V, 7 kWh battery pack for a Formula SAE student racing electric car. The pack is made up of 6 individual segments which are connected in series. Each segment has a maximum energy of 1.17 kWh and is made up of 16 arrays connected in series. Each array holds 8 Lithium-ion batteries which are connected in parallel. The overall design of the battery pack is in full compliance with the Formula SAE rules. The manuscript presents the calculation procedure and battery sizing for the power demand of a typical Formula SAE student racing electric car using vehicle dynamics equations. The entire electric traction system is modelled in Matlab/Simulink. The paper also explains the development process of the 7 kWh battery pack and highlights important design considerations, such as busbar sizing.

Results from the research projects sponsored by General Motors, Motor Vehicle Fire Research Institute and National Highway Traffic Safety Administration are discussed. In the projects, thermophysical and fire properties of engine compartment fluids and polymer parts of the vehicle were quantified. Burning behaviors of the actual vehicle parts and front and rear crashed vehicle were also examined. Penetration of flames into the passenger compartment was the most critical stage in vehicle crash fire tests. Pain, 2nd and 3rd degree burns, flashover, toxicity, and lethality followed in that order very shortly after the flame penetration. The flame penetration into the passenger compartment from the engine compartment fires in front vehicle crashes was significantly longer (10 to 24 minutes post ignition) than from gasoline pool fires under the vehicle (0.5 to 3.0 minutes post ignition).