Methods of simulating the front of the air shock wave for calculating the industrial structure

Introduction. The paper considers existing methods of simulating a wide front of an air shock wave for solving problems of shock wave interaction with an installation using gas-dynamic methods. When solving the problem of the air shock wave interaction with an installation in a dynamic setting, it was revealed that, when simulating a wide front of a distant explosion using point explosions, it is possible to obtain an underestimated time of the shock wave action. This results in a downward bias of loads to the installation. Thus, the loads obtained in this case do not correspond to the loads for which it is necessary to carry out the calculation of industrial installations protected from shock waves in accordance with domestic and international regulatory documents. To eliminate this drawback, another approach is proposed. It consists in setting the load on the computational region in the form of a pressure graph with specified parameters of overpressure and exposure time. Materials and methods. The interaction of the shock wave front with the installation is carried out using numerical simulation in a nonlinear dynamic setting using gas-dynamic methods in the LS-DYNA software package. Results. The following analyses were conducted in the scope of the study: an analysis of existing methods of forming the wide shock wave front of the distant explosion and an analysis of the parameters of the shock wave during the formation of the wide shock wave front of the distant explosion by setting the pressure graph with the specified parameters of the overpressure and the exposure time. Conclusions. The result of the analysis of methods for numerical simulation of the interaction of the air shock wave wide front with the installation showed that simulation of the explosion source in the form of volume elements and simulation of the shock wave using the CONWEP function of the LS-DYNA software package have disadvantages. These disadvantages do not allow obtaining the main parameters of the shock wave for the further use. A method for modeling the wide shock wave front is given by setting a pressure graph at the boundary of the computational region with the required overpressure parameters and exposure time.