Select a DIFFUSIVITY to set the dispersion rate.Ĥ. Select a FEED-VELOCITY to set the convection rate.ģ. Note that higher concentrations substantially increase computational expense.Ģ. The notable exception are the CONCENTRATION-DEPENDENT and BIMOLECULAR reaction mechanisms, which are density dependent. Note most results are normalized, so the main benefit of higher concentration is less noise in the resultant data. The model is essentially 1-D, but has been constructed in 2-D so as to improve its interpretability. The best way to the learn the model is to play around with parameters and view the results. The patches lining the reactor inlet are asked to sprout reactant at the user-specified concentration. ![]() All surviving molecules are asked to increment their residence time.ĥ. All other molecules are moved to their projected position.ĭ. All molecules with projected position before the feed to the reactor are moved to the reactor inlet.Ĭ. All molecules in the effluent are asked to die.ī. The number and type of molecules entering and leading the reactor are stored such that they may be analyzed later.Ī. All molecules with a projected position beyond the end of the reactor are added to the effluent stream agentset.ī. The molecules do not immediately move to their new position, but rather add their projected random walk to the coordinates projected during the convection step.Ī. If RANDOM-DIFFUSION? is off, the step size is the DIFFUSIVITY. If RANDOM-DIFFUSION? is on, the step size is a random distance less than the DIFFUSIVITY. Diffusion -> Molecules undergo 1-D random walk diffusion by moving forward or backward. The molecules do not immediately move to their new position, but rather store their projected coordinates.ī. Convection -> Molecules are uniformly transported downstream at the specified FEED-VELOCITY. All molecules are affected by two modes of transport:Ī. When a bimolecular reaction occurs, the primary reactant asks the other reactant within its COLLISION-RADIUS to die. When a unimolecular reaction occurs, the reactant changes its breed to product. Bimolecular: Pairs of reactant turtles are converted to products with probability equal to the REACTION-PROBABILITY, but only if two or more reactants are within the COLLISION-RADIUS. Concentration-Dependent: Reactant turtles are randomly converted to products, with probability equal to the product of the REACTION-PROBABILITY and the number of other reactants within the reactant's COLLISION-RADIUS.Ĭ. Concentration-Independent: Reactant turtles are randomly converted to products, with probability equal to the REACTION-PROBABILITY.ī. Three reaction mechanisms are available:Ī. Reactants react at a rate determined by the specified reaction mechanism. Consequently, all such code has been omitted:Īt each tick: 1. ![]() If the FILL-REACTOR? option is switched on, all patches are filled with reactant in this manner.Ī significant portion of the code was written for analysis purposes and is not relevant to the function of the reactor. ![]() On setup, the far left column of patches sprout reactant at a user-specified concentration (number per patch). The model contains three types of molecular entities: Reactants are blue turtles, Products are red turtles, and Inerts are yellow turtles. The reactor is oriented such that the feed stream enters at the left boundary and leaves at the right boundary. For the Eulerian reference frame, see the accompanying model in the RELATED MODELS section below. The model operates from the Lagrangian reference frame, as all notable actions are assigned to mobile turtles. Namely, fluid dynamics and bulk diffusion effects are rolled into a single diffusion mechanism named dispersion. The scope of the model is analogous to that of the convection-dispersion-reaction system taught in undergraduate chemical engineering courses. With further validation and development, the model could in principle be used to design and simulate real chemical reactors, albeit at very high computational cost relative to equation-based methods. ![]() By using simple agent-level rules to recreate a number of known reaction engineering phenomena, the model is designed to serve as an educational tool for chemical engineering students. This is an agent-based approach to modeling continuous-flow chemical reactors.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |