等方性乱流における噴霧燃焼の群燃焼形態

抄録

Numerical simulation of spray combustion in homogeneous isotropic turbulence was performed under realistic time and spatial scales. The simulation was realized by newly developed numerical methods which had a lot of advantage in simulation of unstable subjects. The method was preliminary examined in several situations to prove the method was able to be applied for direct numerical simulation. In non-combusting cases, we found liquid droplet followed typical “preferential effect” and number density fields of droplets showed homogeneous and heterogeneous distribution according to Stokes number. The effect appeared in both small and large structural turbulences. In combusting cases, flame formation also varied by the Stokes number in turbulence where large structure existed in flow field. On the other hand, in turbulence with small structure, the regimes became homogeneous regardless of the Stokes number. We defined “local group combustion number” which was different from existing one, however it was convenient to understand the combustion regime variation and it could explain how combustion was proceeded.