The article describes the topicality, formulation of the problem, the structure, the basic equations and the solution method, as well as the specifics of using TOXI+CFD software package that implements the numerical solution of the hydrodynamic equations (the so-called CFD methods — Computational Fluid Dynamics). The simulation is based on an approach based on standard partial differential equations of the laws of conservation of mass, momentum and energy. The use of CFD methods will allow more accurate modeling of cloud formation and explosions of fuel-air mixtures in three-dimensional space. The software for calculating the propagation of waves of overpressure in the 3D cluttered environment developed and tested in this work. The verification of the TOXI+CFD calculation results obtained by comparison with the analytical solution of the Sod’s problem, as well as experimental studies of shock waves in a shock sphere. The results of measurements obtained in experiments, as well as using TOXI+CFD demonstrate the limiting deviations of the results for the grid of 3,4 million cells — no more than 9 %, and for the grid of 8 million cells — no more than 7 %, which is an indicator of the satisfactory quality of the model. It also follows from the results that as the number of cells increases, the calculated pressure becomes closer to the experimental values by 1–2 %, which indicates the convergence of the solution. The features of the software package are presented, such as the presence of a graphical user interface, the ability to work under Windows and Linux operating systems, support for cluster computing, as well as the main stages of its use. At the next stage of works on TOXI+CFD improvement it is planned to add turbulence and gravity model to the software package, and subsequently the atmosphere model taking into account stratification and combustion model.
V.A. Shargatov, Cand. Sci. (Phys.-Math.), Associate Professor S.I. Sumskoi, Cand. Sci. (Eng.), Senior Lector NIYAU MEPhI, Moscow, Russia A.S. Sofyin, Cand. Sci. (Eng.), Department Head, toxi@safety.ru STC «Industrial Safety» CJSC, Moscow, Russia
The article describes the topicality, formulation of the problem, the structure, the basic equations and the solution method, as well as the specifics of using TOXI+CFD software package that implements the numerical solution of the hydrodynamic equations (the so-called CFD methods — Computational Fluid Dynamics). The simulation is based on an approach based on standard partial differential equations of the laws of conservation of mass, momentum and energy. The use of CFD methods will allow more accurate modeling of cloud formation and explosions of fuel-air mixtures in three-dimensional space. The software for calculating the propagation of waves of overpressure in the 3D cluttered environment developed and tested in this work. The verification of the TOXI+CFD calculation results obtained by comparison with the analytical solution of the Sod’s problem, as well as experimental studies of shock waves in a shock sphere. The results of measurements obtained in experiments, as well as using TOXI+CFD demonstrate the limiting deviations of the results for the grid of 3,4 million cells — no more than 9 %, and for the grid of 8 million cells — no more than 7 %, which is an indicator of the satisfactory quality of the model. It also follows from the results that as the number of cells increases, the calculated pressure becomes closer to the experimental values by 1–2 %, which indicates the convergence of the solution. The features of the software package are presented, such as the presence of a graphical user interface, the ability to work under Windows and Linux operating systems, support for cluster computing, as well as the main stages of its use. At the next stage of works on TOXI+CFD improvement it is planned to add turbulence and gravity model to the software package, and subsequently the atmosphere model taking into account stratification and combustion model.
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