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This paper presents the issue of determining the blast load on an engineering structure. In cases of industrial accidents or terrorist attacks, in many cases it is necessary to determine the necessary explosion parameters to determine the response of the structure, preferably in a simple and time-saving manner. In such a way, the empirical relationships can be used to estimate the selected parameters of the explosion load. Many empirical relationships have been derived in the past, but not all are suitable for different types of explosions. This article compares and validates experimentally determined selected explosion parameters for the chosen explosive with empirical relationships. For comparison, three already verified and frequently used calculation procedures (Kingery, Kinney, Henrych) and one newly derived procedure (PECH) were used. As part of the experimental measurements, blast wave explosion parameters for small charges were determined for near-field explosions. The general-purpose plastic explosive Semtex 10-SE was used for the experiments. The results of the comparative study presented in this article demonstrate the importance of taking these procedures into account for a reliable determination of the effects of blast actions on buildings.

Abstract. The contribution deals with quantification of natural gas leak from a domestic low pressure pipe to a confined space in relation to formation of explosive concentration. Within the experiments, amount of leak gas was determined considering the character of pipe damage. Leakage coefficients, natural gas expansion and time before reaching the lower explosive limit of a gas-air mixture were taken. Conducted experiments were then modelled using CFD software and the results were verified. In numerical model, several models of flow were used and afterwards following issues were analysed: leakage velocity, spatial distribution of the mixture in a confined space, formation of concentration at the lower explosive limit etc. This work should contribute to better understanding of propagation and distribution of gaseous fuel mixtures in confined spaces and thereby significantly reduce the risk of fires or explosions or prevent them.

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Abstract. Very rapid physical and chemical processes during the explosion require both quality and quantity of detection devices. CFD numerical simulations are suitable instruments for more detailed determination of explosion parameters. The paper deals with mathematical modelling of vented explosion and turbulent flame spread with use of ANSYS Fluent software. The paper is focused on verification of preciseness of calculations comparing calculated data with the results obtained in realised experiments in the explosion chamber.