Influence of controllable slit width and angle of controllable flow on hydrogen/air premixed combustion characteristics in micro combustor with both sides–slitted bluff body

Abstract

To improve the combustion stability of micro combustor, both sides-slitted bluff body is applied to the micro combustor. The H2/O2 reaction mechanism is used to study the influence of controllable slit width (d) and angle of controllable flow (β) on combustion characteristics of the micro-combustor. The result shows that the reduction of d can significantly improve the combustion efficiency. Under the same controllable flow ratio (γ), the reduction of d can effectively expand the recirculation region. However, the blow-off limit will be reduced if d is too large or too small. With the same γ, the recirculation region and low-velocity zone expand when β decreases, which can entrain more high-temperature gas and increase the residence time of fuel in the low-velocity zone, thus improving the combustion efficiency. The residence time of fuel in the combustor will be reduced when β is too large or small, resulting in lower combustion efficiency and blow-off limit. Therefore, it is significant to choose the parameter of d and β.