The Deflagration Effects of Premixed Methane–Air Cloud with Buildings in Open Space

To investigate methane-premixed gas cloud deflagration consequences, we developed a computational fluid dynamics (CFD) model for natural gas deflagration. Validation against large-scale pipeline explosion experiments preceded the examination of characteristic parameters of gas cloud and building presence effects on deflagration fireball thermal radiation and overpressure. Results indicate that open-space deflagration yields increasing external overpressure with equivalence ratios below 1.4; identical-area circular clouds exhibit 10% higher thermal radiation growth rates and greater overpressure increases than square counterparts; nonuniform gas distribution reduces thermal radiation (magnitude dependent on heterogeneity); frontal radiation exceeds lethal limits within 150 m of leakage points; buildings confer significant shielding, establishing safety beyond 200 m; increased building height accelerates surface thermal attenuation; rooftops occupy thermal decay transition zones where attenuation rates intensify with height.