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This paper describes ongoing research conducted by the National Highway Traffic Safety Administration (NHTSA) to evaluate the potential of safety restraints on large school buses. School bus transportation is one of the safest forms of transportation in the United States. Large school buses provide protection because of their visibility, size, and weight, as compared to other types of motor vehicles. Additionally, they are required to meet minimum Federal Motor Vehicle Safety Standards (FMVSS) mandating compartmentalized seating, emergency exits, roof crush and fuel system integrity, and minimum bus body joint strength.

Requirements for reduced fuel consumption with simultaneous reductions in regulated emissions require more efficient operation of Spark Ignited (SI) engines. An advanced valvetrain coupled with Gasoline Direct injection (GDi) provide an opportunity to simultaneously reduce fuel consumption and emissions. Work on a flex fuel GDi engine has identified significant potential to reduce throttling by using Early Intake Valve Closing (EIVC) and Late Intake Valve Closing (LIVC) strategies to control knock and load. High loads were problematic when operating on gasoline for particulate emissions, and low loads were not able to fully minimize throttling due to poor charge motion for the EIVC strategy. The use of valve deactivation was successful at reducing high load particulate emissions without a significant airflow penalty below 3000 RPM. Valve deactivation did increase the knocking tendency for knock limited fuels, due to increased heat transfer that increased charge temperature.

There are many mechanisms for ankle injury to front seat occupants involved in automotive impacts. This study addresses injuries to the ankle joint involving inversion or eversion, in particular at high rates of loading such as might occur in automotive accidents. Injuries included unilateral malleolar fractures and ligament tears, and talus and calcaneous avulsions. Twenty tests have been performed so far, two of them using Hybrid III lower leg and the rest using cadaveric specimens. The specimens were loaded dynamically on the bottom of the foot via a pneumatic cylinder in either an inversion or eversion direction at fixed dorsiflexion and plantarflexion angles. The applied force and accelerations have been measured as well as all the reaction forces and moments. High-speed film was used to obtain the inversiordeversion angle of the foot relative to the tibia and for following ligament stretch.

A flow network method was developed to predict the underhood temperature distribution of an automobile. The method involves the solution of simplified energy and momentum equations of the air flow in control volumes defined by subdividing the air space between the surfaces of the underhood components and the front-end geometry. The control volumes are interconnected by ducts with branches and bends to form a flow network. Conservation of mass and momentum with appropriate pressure-loss coefficients leads to a system of algebraic equations to be solved for the flow rates through each volume. The computed flow rates are transferred to a thermal model to calculate the temperatures of the air and the major vehicle components that affect the underhood environment. The method was applied to a 1986 3.0L Taurus and compared with vehicle experiments conducted in a windtunnel.

This paper addresses the protection of occupants in light vehicles. It presents data and techniques for identifying and measuring potential crashworthiness improvements that would mitigate injuries to occupants striking frontal interior components such as the steering wheel, instrument panel and windshield. Both restrained and unrestrained occupants can be injured by frontal interior components in crashes. The focus of this paper is on the unrestrained occupant. However, performance criteria and associated countermeasures will have to be developed considering the differences in the mechanisms of injury to both the restrained and unrestrained occupants. Work on the restrained occupant and the similarities and differences between both conditions remains to be considered. The paper presents information on the magnitude and types of injuries received from frontal interior components and on how the performance of these components and the vehicle structure affect the resultant injuries.

The injury reducing effectiveness of child safety seats in frontal crashes was evaluated, based on 36 frontal or oblique sled tests run with two or more GM three-year-old dummies in the simulated passenger compartment of a car. Unrestrained, correctly restrained and incorrectly restrained dummies were tested at the range of speeds where most nonminor injuries occur (15-35 mph). Accident data from NHTSA files were used to calibrate a relationship between the front-seat unrestrained dummies' HIC and unrestrained children's risk of serious head injuries; also between torso g's and the risk of serious torso injuries. These relationships were used to predict injury risk for the restrained children as a function of crash speed and to compare it to the risk for unrestrained children. The sled test analysis predicted that the 1984 mix of correctly and incorrectly used safety seats reduced serious injury risk by 40 percent relative to the unrestrained child, in frontal crashes.

As engine efficiency targets continue to rise, additional improvements must consider reduction of heat transfer losses. The development of advanced heat transfer models and realistic boundary conditions for simulation based engine design both require accurate in-cylinder wall temperature measurements. A novel dual wavelength infrared diagnostic has been developed to measure in-cylinder surface temperatures with high temporal resolution. The diagnostic has the capability to measure low amplitude, high frequency temperature variations, such as those occurring during the gas exchange process. The dual wavelength ratio method has the benefit of correcting for background scattering reflections and the emission from the optical window itself. The assumption that background effects are relatively constant during an engine cycle is shown to be valid over a range of intake conditions during motoring.

A hot and cold water mixing process with a steam condenser and a chilled water heat exchanger is set up for an engine EGR fouling test. The test rig has water recycled in the loop of a pump, heat exchangers, a three-way mixing valve, and a test EGR unit. The target unit temperature is controlled by a heating, cooling and mixing process with individual valves regulating the flow-rate of saturated steam, chilled water and mixing ratio. The challenges in control design are the dead-time, interaction, nonlinearity and multivariable characteristics of heat exchangers, plus the flow recycle in the system. A systems method is applied to extract a simple linear model for control design. The method avoids the nonlinearity and interaction among different temperatures at inlet, outlet and flow-rate. The test data proves the effectiveness of systems analysis and modeling methodology. As a result, the first-order linear model facilitates the controller design.

From our crash investigations of air bag equipped passenger cars, a subset of upper extremity injuries are presented that are related to air bag deployments. Minor hand, wrist or forearm injuries-contusions, abrasions, and sprains are not uncommonly reported. Infrequently, hand fractures have been sustained and, in isolated cases, fractures of the forearm bones or of the thumb and/or adjacent hand. The close proximity of the forearm or hand to the air bag module door is related to most of the fractures identified. Steering wheel air bag deployments can fling the hand-forearm into the instrument panel, rearview mirror or windshield as indicated by contact scuffs or tissue debris or the star burst (spider web) pattern of windshield breakage in front of the steering wheel.