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As OEMs race to build their sales fleets to meet ever more stringent California Air Resources Board (CARB) mobile source evaporative emissions requirements, new technologies are emerging to control pollution. Evaporative emissions emanating from sources up-stream in the induction flow and venting through the ducts of the engine air induction system (EIS) need to be controlled in order classify a salable vehicle as a Partial Zero Emissions Vehicle (PZEV) in the state of California. As other states explore adopting California's pollution control standards, demand for emissions control measures in the induction system is expected to increase. This paper documents some of the considerations of designing an adsorbent evaporative emissions device in to a 2007 production passenger car for the North American and Asian markets. This new evaporative emissions device will be permanently installed in the vehicle's air cleaner cover without requiring service for 150K miles (expected vehicle life).

Passive, tuned acoustic absorbers, such as Helmholtz resonators (HR) and quarter-wave tubes, are commonly used solutions for abating the low-frequency tonal noise in air induction systems. Since absorption at multiple frequencies is required, multiple absorbers tuned to different frequencies are commonly used. Typically, the large size and multiple numbers of these devices under the hood is a packaging challenge. Also, the lack of acoustic damping narrows their effective bandwidth and creates undesirable side lobes. Active noise control could address all of the above-mentioned issues. Most active noise control systems use feedforward adaptive algorithms as their controllers. These complex algorithms need fast, powerful digital signal processors to run. To ensure the convergence of the adaptation algorithm, the rate of adaptation should be made slow.

The function of the engine air cleaning filter is to remove the particulate matter in the intake air to protect the engine and its components from wear and contamination. For a specific filter, the efficiency is a function of the size of the particles being collected and the air flow velocity through the filter. Traditional tests of engine air cleaners are based on the use of specific test dusts, such as the AC Coarse and AC Fine, to determine the mass collection efficiency. However, they do not provide information on the size dependent performance of the filters, and the variation in filter performance under different particle challenge conditions. The use of a fractional efficiency test method will help to provide this missing information. The purpose of this paper is to describe a fractional efficiency test system that has been designed to evaluate the fractional cleaning efficiency of engine air cleaning filters in the size range between 0.3 and 10 mm particle diameter.