The Study on the Shock Wave Propagation Rule of a Gas Explosion in a Gas Compartment

Abstract

Combined with the k-ε turbulence model of general application, a refined finite element model of a utility tunnel’s gas compartment filled with the methane/air mixture is developed. A series of analyses are made by using the powerful industry-leading computational fluid dynamics (CFD) software flame acceleration simulator (FLACS) to study the shock wave propagation rule in the gas compartment. The longitudinal and transversal distribution laws of the explosion shock wave are gained taking into consideration the spatial characteristics of the gas compartment. The influences of a few parameters, such as initial conditions and section size of the gas compartment, on the shock wave propagation rule are further discussed. The basic procedure for predicting the peak pressure of the blast wave is provided by considering the initial conditions and the gas compartment, and the corresponding injury effect of the explosion wave on the living beings is assessed. The investigation demonstrates that the peak pressure by the coupled effect between the initial conditions is significantly influenced, especially at the upper and lower gas explosion limits. The peak pressure increases gradually as the width or height increases, and both basically meet the linear relation. The proposed method can forecast the peak pressure of the explosion shock wave in the gas compartment accurately. According to the peak pressure longitudinal and transversal distributions of the blast wave, the peak pressure is far greater than the killing pressure threshold in the underground and closed space; consequently, it is not safe for the living beings in the gas compartment.

Analysis of Load Transfer Law of Short Pile-Net Composite Foundation for High-Speed Railway

“…Base. Based on the transverse distribution curve of Earth pressure along the base, the stress variation characteristics of the foundation at different transverse positions during the loading filling process of the upper embankment could be investigated; thereby the design parameters of composite foundation could be optimized [30][31][32][33]. Figure 3 shows the curve of the Earth pressure distribution along the base in the natural foundation and in the pile-net composite foundation.…”