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Vehicle fire investigators often use the existence of burn patterns, along with the amount and location of fire damage, to determine the fire origin and its cause. The purpose of this paper is to study the effects of ventilation location on the interior burn patterns and burn damage of passenger compartment fires. Four similar Ford Fusion vehicles were burned. The fire origin and first material ignited were the same for all four vehicles. In each test, a different door window was down for the duration of the burn test. Each vehicle was allowed to burn until the windshield, back glass, or another window, other than the window used for ventilation, failed, thus changing the ventilation pattern. At that point, the fire was extinguished. Temperatures were measured at various locations in the passenger compartment. Video recordings and still photography were collected at all phases of the study.

Vehicle fire investigators sometimes use the existence and location of thermally damaged wiring (arced, shorted, melted, & beaded) discovered in a post burn analysis of a vehicle as an indication of the fire origin and its cause. One systematic method of analysis is to use the process of arc mapping. To examine the reliability of arc mapping in motor vehicle fires, two full scale burn demonstrations were conducted on 2013 Ford Fusions. Both vehicles had similar fire origins artificially initiated in the interior of the vehicles near the driver’s front seat. The engines were running and all accessories were off. During the burn sequence, occurrences of fire induced unintended electrical activity were captured with video and still photography. Examples of this unintended activity include lights, horn, wipers, and decklid latch activation. The burn concluded when the measured battery voltage went to zero in demonstration 1.

Four full scale burn tests on aluminum body Ford F-150’s were conducted with four unique origins. The purpose of these burn tests was to determine if the origin of the fire could be accurately identified after the vehicle fires progressed to near complete burn (with near absence of the aluminum body panels). The points of origin for the four burn tests were: 1) Engine Compartment - driver’s side front of engine compartment, 2) Passenger Compartment - Instrument panel, driver’s side near the headlamp switch, 3) Passenger Compartment - passenger side rear seat, 4) Outside of Vehicle - passenger side front tire. Photographic, video, and temperature data was recorded to document the burn process from initiation to extinguishment. Post-fire analysis was conducted in an attempt to determine the origin of the fire based solely on the burn damage.

This paper discusses the optimization of an automotive hydraulic steering pump pulley design for improved in-vehicle pump NVH performance. Levels of steering pump whine noise heard inside a vehicle were deemed objectionable. Vehicle and component transfer path analyses indicated that the dominant noise path for the whine noise was airborne in nature. Subsequent experimental modal analysis indicated that the steering pump pulley was a major contributor to the amount of radiated noise produced by the pump/pulley system. CAE analysis was used to further analyze the dynamic behavior of the pulley and develop an optimized design with decreased noise radiation efficiency. The results predicted with the CAE analysis were verified in-vehicle, resulting in a vehicle with acceptable steering pump whine noise performance.