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As a part of developing automotive fuel vapor emission control, a two dimensional, time-accurate simulation capability for adsorption/desorption in a carbon canister has been developed. Dubinin-Polanyi adsorption potential model has been used for n-butane (a surrogate for gasoline vapor) adsorption at ambient pressure on activated carbon adsorbent of Westvaco product BAX 950, and nitrogen was chosen as the carrier gas. Linear driving force model is used for heat and mass transfer rates. The impacts of different n-butane concentration on the adsorption phenomena and different initial carbon bed equilibrium adsorption states on desorption phenomena are studied. Results such as adsorption breakthrough curve, desorption curve, adsorption amount, n-butane mole fraction and temperature profiles are provided. Comparisons with results from previous work are made to verify the current model.

Computational fluid dynamics simulations of fixed-bed adiabatic adsorption/desorption processes are presented in this paper. Linear driving force model is used for heat and mass transfer rates. A two-dimensional cylindrical canister and three-dimensional automotive production canister geometry are used to study the adsorption/desorption processes of carbon dioxide in helium carrier gas on Norit B4 activated carbon. The two-dimensional results compare well with the results of Hwang et al. [1]. Computational results as breakthrough curve, adsorption amount and temperature profiles are provided. Results show that non-adiabatic model should be used to fully utilize the activated carbon bed capacity prior to breakthrough.

In this paper, the application of Shallow Water Modeling (SWM) method to simulate the compressible viscous plane flow for studying squish movement in combustion chambers of diesel engines is reported. The principle and analogue criteria of this method are discussed and derived. Using this method combined with visualization technique, the flow patterns were obtained and compared with those obtained by other methods. T1te results show that the SWM method is adequate and favorable for such investigation.

Using a Laser Doppler Velocimetry with Burst Spectrum Analyzer (LDV-BSA), droplet velocities of a diesel fuel spray under a pressure higher than 100 MPa were measured at different points within the spray profile. Results show that although the mean velocity distribution at the sampling plane is rather uniform, the number-based droplet velocity distributions of two sampling points at the same plane are different. The conclusions agree with theoretical predictions through maximum entropy principle qualitatively.