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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.

Today's automotive Air Induction Systems (AIS) are designed to deliver overall superior filtration performances because of increased engine protection requirements. In addition it must also meet packaging requirements, higher flow rates, lower system restriction, serviceability and induction noise. Studies have shown that the size and concentration levels of dust ingested need to be controlled to reduce engine wear. Major air filtration technologies currently available and used on AIS are also presented. Criteria for filter selection have also been discussed based on field data. Engineering and design parameters are also briefly discussed for developing robust engine air induction filters. Development of a new conical filter element is presented for the Ford ‘Conical AIS’ including performance data. This development also includes process/manufacturing and engineering specifications for the new conical program.

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.

The performance of the air cleaning filter is important to the long-term performance and reliability of the engine and its components. In this study, the performances of cellulosic and foam filter media for engine air cleaning application are experimentally investigated. Phenolic and non-phenolic cellulose filters were studied. Both flat-sheet and pleated cellulose filters were included. The foams filters were reticulated polyurethane foam media from 20 to 110 pores-per-inch. We measured the initial air flow resistance, the collection efficiency as a function of particle size, and the behavior of dust loading. We also studied the effect of oil treatment on filter performance. The results show that the efficiencies and pressure drops of the cellulose filters increase rapidly with dust loading. Oil treated cellulose filter was found to exhibit slower increases in pressure drop and collection efficiency, resulting in higher dust holding capacity.

Fuel Vapor Storage Systems (FVSS) on automobiles are susceptible to particle contamination. This is especially true for FVSS components mounted under the automobiles (undercarriage, chassis frame, etc.) and required to meet stringent EPA standards. Particle contamination significantly increases system restriction and reduces the effectiveness of FVSS. This paper describes a dust separator/filter developed to protect the FVSS. Accelerated field durability evaluations and measurement techniques were developed to identify clean locations, ingested contamination levels and ingested contaminant size distributions. Based on field evaluations, test methods were developed in the lab to evaluate effectiveness of several devices to control and reduce contamination. The dust separator design developed was a combination of baffle separators in series with an open cell foam filter. The dust separator was designed to meet and exceed several vehicle system design requirements.