Exhaust purification for lean-burn internal combustion engines has been impaired by the relatively low temperature of the exhaust that makes conventional passive aftertreatment schemes less energy-efficient in oxidation/regeneration. To tackle such adversaries, an active-flow control scheme, reversal-flow control, is outlined and analyzed in this paper. Preliminary energy-efficiency analyses are performed with different gas flow rate, flow reversal frequency, and monolith-solid properties. Simulation results indicate that through active thermal management the supplemental energy consumption can be drastically reduced, which is also supported by previous empirical studies.
An Electrostatically-Actuated Microvalve for Semiconductor Gas Flow Control