We address the control of the airpath of a turbocharged S.I. engine equipped with Variable Valve Timing actuators (VVT). Compared to standard configurations, the engine does not possess any external EGR (Exhaust Gas Recirculation) loop. Rather, VVT are used to produce internal EGR, providing similar beneficial effects in terms of emissions reduction. The airpath dynamics takes the form of a sin...

The fundamentals of catalyst deactivation are presented in this review. The chemico-physical aspects concerning the various deactivation causes (i.e. poisoning, sintering, coking, solid-state transformation, masking, etc.) have been analyzed and discussed, along with the mathematical description of the deactivation phenomena. # 1999 Elsevier Science B.V. All rights

The hot gases produced by the internal combustion engines passes through the exhaust valve and causes high temperatures in the exhaust valve and its seat. To avoid damaging the exhaust valve, heat must be transferred from the valve to its seat during the contact they make at the opening and closing cycle. Heat transfer rate from the exhaust valve to its seat is a function of many factors. One o...

The intake port of a CA4DD diesel engine was investigated by computational fluid dynamics (CFD) numerical simulation to enhance the swirl and improve flow characteristics in engine. uniform design method applied study influence guide vanes with different parameters on process at various valve lifts. Nine vane models were established compared base model using CATIA™ 3D CAD software. Numerical si...

Engine downsizing is a trusted method to reduce fuel consumption and pollution emitted from internal combustion engines. In this method, engine displacement volume reduced while maintaining the same power/torque characteristics. However, there still exist several limitations utilize technology. paper, naturally aspirated type of Iran national (EF7-NA) investigated for possible downsized version...

Deactivation of heterogeneous catalysts is a ubiquitous problem that causes loss of catalytic rate with time. This review on deactivation and regeneration of heterogeneous catalysts classifies deactivation by type (chemical, thermal, and mechanical) and by mechanism (poisoning, fouling, thermal degradation, vapor formation, vapor-solid and solid-solid reactions, and attrition/crushing). The key...

A 1arge-scale tumble rather than swirl would exist in cylinders in the case of two valves’ opening in a fourvalve engine. A strong swirl is generated when one valve is closed, yet the flow capacity is less than that of two valves being opened. In order to change it, different lifts of valves (DLV) present are achieved. In the case of using different lifts of two intake valves, both tumble and s...