Compared with semi-spherical flammable gas cloud model

cylindrical model could represent cloud explosion accidents more exactly.Experiments of cylindrical gas cloud explosion were performed with 7.75 % of ethyne and 0.26 m3 of gas cloud volume and overpressures at 1.2 m and 1.6 m points from cloud center were recorded.A theoretical model of cloud explosion was established and SIMPLE algorithm was adopted in writing calculated codes.Compared with the test data

the maximum and average relative deviations of calculation results were 18.3% and 5.4% respectively

which showed that the codes met the need to simulate the cloud explosion.This work indicated that the explosion intensity was related to flame spread direction and the explosion field was not spherically symmetric.The maximum explosion overpressure close to the ground was about 3.3 times higher than that along the vertical direction when the ratio of height and radius of the cloud was 0.2.The explosion intensity increased with increasing ratio of height and radius of gas cloud

and the maximum overpressure should increase by 3.1 times when the ratio changed from 0.1 to 1.0.When the ratio decreased

the distance of flame spread increased and the time of inflammation delayed

which led to decreasing energy transfer of gas cloud and falling explosion overpressure.The research results are of some significance to predict the disaster of flammable gas cloud explosion.