Flame Stabilization Characteristics of Strut Divided into Two Parts in Supersonic Airflow

Flame stabilization experiments were conducted in a supersonic airflow of Mach number 1.5, using a strut divided streamwise into two parts. Hydrogen gas was injected into the interval between the two parts of the strut. The flame stabilization was definitely affected by whether the combustion region could be established in this space, and the flame stabilization characteristics changed drastically according to the distance between the two parts of the strut. A shadowgraph and schlieren photographs showed that no shock waves or expansion waves existed in the intervening space, and that waves did not directly control the flame-stabilization mechanism that was altered by the distance between two parts. In order to explain the present characteristic flamestabilization from the standpoint of the competition between mass transfer and reaction, the velocity fields were measured by laser Doppler velocimeter, and the residence times in the intervening space were estimated. Through these observations and measurements, the flame-stabilization mechanism was clarified and the usefulness of this type of strut was demonstrated.