A CFD study of the effects of combined impurities, ground temperature, and topography upon the consequence distances and plume shapes generated by CO2 release from CCS pipeline failure.

In the carbon capture and storage (CCS) infrastructure, the risk of a high-pressure buried pipeline rupture possibly leads to catastrophic accidents due to the release of tremendous amounts of carbon dioxide (CO2). Therefore, it is crucial to conduct an in-depth study on CO2 atmospheric dispersion when developing CO2 pipeline. In fact, the CO2 captured from diverse industrial processes may contain a variety of impurities. The combined effect of the toxicities of the multiple impurities increases the risk, which has usually been ignored by previous studies. In this paper, computational fluid dynamics (CFD) technology is applied to investigate the influence of hazardous chemicals on CO2 stream dispersion under different meteorological, complex terrain features, and ground temperature condition. In addition, the effect of combined toxic impurities on consequence distance was also investigated comprehensively. It was found that complex conditions affected the near-surface flow field, and obstacles enhanced the lateral dispersion of CO2. Compared to 288 K ground temperature, the plume area inside the 50,000 ppmv CO2 boundary decreased by 8.2%. The hazardous effects of combined toxic impurities became significant compared to a single toxic impurity. This study may furnish a viable assessment technique for the risks associated with CCS.

A simulating method for dripping process of Ginkgo biloba leaf dripping pills based on computational fluid dynamics technology / 药学学报

A simulating method for dripping process of Ginkgo biloba leaf dripping pills based on computational fluid dynamics was constructed. Ginkgo biloba leaf dripping pills was explored as the experimental subject to simulate the dripping process based on FLOW-3D software. The dripping process was simulated through the derivation of the governing equations, the selection of the models, and simulation parameters. Firstly, the droplet morphologies and drop speeds under different liquid viscosity were simulated. It was found that with the increase of the liquid viscosity, the drop speed decreased and the difficulty of droplet preparation gradually increased. The simulation results were consistent with the experiment results. Secondly, the droplet morphologies at different drop speeds were investigated and verified by experiments. It was found that the simulation results had a good correlation with the experiment results. The results shown that the viscosity of the liquid was the critical material attribute, and the drop speed was the critical process parameter, according to the droplet morphology. The establishment of the simulation method can deepen the understanding of the dripping process and provide a reference for the selection of raw materials and process parameters.