No abstract

No abstract

In this paper, a simple procedure based on fast and slow reaction asymptotics has been employed to derive first-order closure models for the nonlinear reaction terms in turbulent mass balances from mechanistic models of turbulent mixing and reaction. The coalescence-redispersion (CRD) model, the interaction by exchange with the mean (IEM) model, the three-environment (3E) model, and the four-environment (4E) model have been used to develop closure equations. The closure models have been tested extensively against experimental data for both single and multiple reactions. The closures based on slow asymptotics for the CRD, 3E and 4E models provide very good predictions of all of the experimental data, while other models available either in the literature or derived here are not adequate. The simple new closure equations developed in this paper may be useful in modeling systems involving turbulent mixing and complex chemical reactions. showed that all of these models possess an analogy to theories of isotropic turbulent micromixing as expressed by AlChE Journal -_ cm'/s rnol/m' k , = 1.3 x 10' m'/mol/s; k2 = 2.3 m'/mol/s; 7" = 2.0 s; U = 1.6 cm/s AlChE Journal

SynopsisThe effect of fillers on the reaction of liquid epoxy systems cured with rn-phenylenediamine has been studied within the temperature range 70-170°C using a Perkin-Elmer differential scanning calorimeter. Quantitative studies have been made with regard to the effect of fillers on the kinetics of cure. Mathematical expressions have been devised to describe the curing reaction as a function of time, temperature, and filler content. These kinetic expressions were found to yield results which were in gooa agreement with the experimental data for the two fillers studied.

No abstract