Numerical Simulations on the Explosive Cyclogensis over the Kuroshio Current

In this paper,the Pennsylvania State University-NCAR Mesoscale Model (MM4)is used to investigate the explosive oceanic cyclone of 14-15 March 1988 over the warm Kuroshio Current. A series of numerical simulations on this cyclogenesis indicates that the favorable weather conditions and strong baroclinity in the low- and middle-level are essential to its explosive development. The explosive cyclogenesis occurred over a wide range of sea surface temperatures (SST′s),which was then characterized by strong baroclinity,the low-level jet (LLJ) was initially formed under the favorable atmospheric circulation and then this LLJ advected the moisture and heat northward for the explosive development of the cyclone,the LLJ played an important role in the process of cyclogenesis.Sensitivity experiments show that the latent heating was a key factor to explosive cyclogenesis,the latent heating deepened the short-wave trough,which resulted in the rapid intensification of the cyclone; while in the explosive intensification stage and continuous development stage, there was less contribution of local surface processes for the explosion of the cyclone.

Simulation Analysis of Indoor Gas Explosion Damage

The influence factors and process of indoor gas explosion are studied with AutoReaGas explosion simulator. The result shows that venting pressure has great influence on the indoor gas explosion damage. The higher the venting pressure is, the more serious the hazard consequence will be. The ignition location has also evident effect on the gas explosion damage. The explosion static overpressure would not cause major injury to person and serious damage to structure in the case of low venting pressure (lower than 2 kPa). The high temperature combustion after the explosion is the major factor to person injury in indoor gas explosion accidents.

Quantitative Method of the Structural Damage Identification of Gas Explosion Based on Case Study:The Shanxi “11. 23” Explosion Investigation

In order to present a retrospective analysis of exposition accidents using input data from investigation processes,data from a specific accident was examined,in which we analyzed possible involved gas species（ liquefied petroleum gas; nature gas） and computed their concentrations and distributions based on the interactions between the structures and the effects of the explosion. In this study,5 scenarios were created to analyze the impact effect. Moreover,a coupling algorithm was put into practice,with a practical outflow boundary and joint strength are applied. Finally,the damage effects of each scenario were simulated. Our experimental results showed significant differences in the 5 scenarios concerning the damage effects on the building structures. The results from scenario 3 agree with the accident characteristics,demonstrating the effectiveness of our proposed modeling method. Our proposed method reflects gas properties,species and the concentration and distribution,and the simulated results validates the root cause,process,and consequences of accidental explosions. Furthermore,this method describes the evolution process of explosions in different building structures. Significantly,our model demonstrates the quantatative explosion effect of factors like gas species,gas volumes,and distributions of gases on explosion results. In this study,a feasible,effective,and quantitative method for structure safety is defined,which is helpful to accelerate the development of safer site regulations.