Near-field prediction of chemical hazard diffusion based on improved differential evolution algorithm and fireworks algorithm

In view of the advantages of CFD technology in the simulation of small and medium-scale chemical hazard diffusion, one near-field prediction model of chemical hazard diffusion named CHDNFP is constructed based on CFD technology, and the accuracy and efficiency of the model are improved by improved differential evolution algorithm (DEA) and fireworks algorithm (FWA). Firstly, based on the component conservation equation, momentum conservation equation, and turbulence control equation, CHDNFP model is constructed, whose basic solution process is proposed from three aspects: non-uniform mesh refinement in diffusion space, model discretization, and iterative solution of control equation. Secondly, comprehensive considering the global search ability, local search ability, and convergence characteristics of integrated DEA and FWA, a hybrid optimization algorithm IDEFWA is designed, which is suitable for predictive model solving. Finally, the CHDNFP model and IDEFWA are verified by tracer experiments. The result shows that: IDEFWA can reduce the relative root mean square error between the predicted concentration field and the observed concentration field to about 25%, with the calculation accuracy of 10^-19 and the standard deviation accuracy of 10^-9; compared with ABCA and GA, IDEFWA can get more accurate solutions faster under the same algebraic and population conditions; the calculation accuracy of CHDNFP-IDEFWA and PISOFOAM is almost the same, where the relative difference is about 3%, and CHDNFP-IDEFWA has better calculation accuracy than PISOFOAM, which is improved by about 26.05%.