Abstract
An experimental investigation was conducted on the structure of turbulent diffusion flames of hydrogen stabilized on a bluff body. A coaxial jet diffusion flame was formed using a cylindrical nozzle with an extremely thick rim, which works as a bluff body. In the present study, special attention was paid to the effect of combustion on the aerodynamic processes. The following results were obtained. (1) The combustion markedly enhances the penetration of the central fuel jet. (2) The laminarization phenomenon, reported in simple jet diffusion flames, was observed more conspicuously in this combustion field as well, and it was assumed to exert an important influence on the flame structure. (3) An accelerating flow field often exists in complicated flow fields with a reverse flow, where turbulence generation terms containing Reynolds normal stress become negative. This phenomenon sometimes exerts considerable effects on the turbulence behavior.
