Influence of liquid bridge force on physical stability during fuel storage and transportation

The physical stability of solid-liquid fuel is a factor that needs to be considered for fuel product practicability for storage and transportation. To determine the Influence of liquid bridge force on physical stability, two detection devices were designed. The laws obtained from microscopic experiments are used to verify the physical stability of fuel under different component ratios. The liquid bridge force is found to increase with the droplet volume. Multiliquid bridges above one critical saturation can generate significant resultant forces compared to single-liquid bridges of the same volume. There exist four states of solid-liquid mixed fuel with increasing liquid saturation rate. The liquid bridge force between the solid and liquid plays a dominant role in the physical stability of the first three states. There may be two stages involved in the stratification process for state 4 fuel, and the liquid viscosity is another factor that cannot be ignored. In the process of selecting a fuel ratio, a larger liquid bridge force between the components can be obtained by properly improving the wetting effect so that the fuel shows better physical stability.

Numerical investigation of the shockwave overpressure fields of multi-sources FAE explosions

Shockwaves from fuel-air explosive(FAE)cloud explosions may cause significant casualties.The ground overpressure field is usually used to evaluate the damage range of explosion shockwaves.In this paper,a finite element model of multi-sources FAE explosion is established to simulate the process of multiple shockwaves propagation and interaction.The model is verified with the experimental data of a fourfoldsource FAE explosion,with the total fuel mass of 340 kg.Simulation results show that the overpressure fields of multi-sources FAE explosions are different from that of the single-source.In the case of multisources,the overpressure fields are influenced significantly by source scattering distance and source number.Subsequently,damage ranges of overpressure under three different levels are calculated.Within a suitable source scattering distance,the damage range of multi-sources situation is greater than that of the single-source,under the same amount of total fuel mass.This research provides a basis for personnel shockwave protection from multi-sources FAE explosion.

Study on explosion process of methane-coal dust mixture

The experimental system of 10 m3 large-scale multiphase combustion explosion tank was used for research into the explosion development process under the ignition conditions of methane-coal dust-air mixture, and the overpressure development processes of the mixture at different distances were obtained. For the methane-coal dust-air mixture with an equivalence ratio of 1, the explosion pressure and pressure rise rate reached their maximum under a methane concentration of 8% and a coal dust concentration of 25 g/m3, while the maximum explosion pressure and pressure rise rate both occurred 0.5 m away from the ignition point under a methane concentration of between 4.5% and 8%, and a coal dust concentration of between 25 g/m3 and 1 O0 g/m3. Moreover, the greater the explosion intensity of mixture, the closer the occurrence location of maximum overpres- sure was to the ignition source.