Numerical Study of the Effect of Model Scaling on Mixing and Flame Development in a Wake Flow Field

Study of the effect of model scaling on combustion and flame-holding is very much warranted because of its theoretical and practical importance. In this study the effect of model scaling was investigated for combustion of hydrogen in supersonic airflow. Parallel Fuel injection is done from the base of a bluff body through a nozzle. Of high interest is how recirculation region behind the bluff body affects combustion and flame-holding. Two scales which directly affect the recirculation region are the width of the base of bluff body and diameter of nozzle. The effects of variation of these two scales on recirculation region, mixing and flame-holding were numerically investigated. The governing equations in conjunction with full chemistry were solved by a high order numerical code. It has been shown that the flame-holding depends on the expansion of mixing region. Moreover, variation of velocity, mixing efficiency and combustion development are given for various geometry of the base and nozzle.