Effects of cloud size and built-in obstacles on hydrogen cloud explosion using large eddy simulation

Abstract

The purpose of this work is to evaluate hydrogen cloud explosion using large eddy simulation. The LES model combined with acoustical theory is firstly established and validated. Then the effects of cloud scale on flame dynamics and explosion pressure are explored. Finally, the effects of obstacle-induced turbulence on hydrogen cloud explosion are analyzed. The research works indicated that the LES model combined with acoustical theory could be able to reproduce flame acceleration and explosion pressure evolution. Maximum explosion pressure and maximum flame front velocity continue to increase with increasing cloud scale. The deviation values of flame radius of four cloud scales are 0.25 m, 0.5 m and 0.75 m, once beyond the critical value, the flame front velocity of larger cloud scale is lower than that of smaller cloud scale. The increase rate of flame front velocity and explosion pressure, not their peak value, will be certainly increased by built-in obstacles, which could be attributed to the couplings of turbulent vortex and moving flame.