A series of experiments have been conducted to study the characteristics of flameholding for twin-plate flameholders. Measurements of lean blow-out limit and ignition limit were carried out on these twin-plate type flameholders and compared to the single-plate and traditional v-gutter flameholders. The twin-plate flameholder is composed of two separate plates with an open slit and an overlap between them. It is designed with AOA = 50° and the design parameters include: open slit width (S), overlap ratio (O/S) and the extension length (D). Results show that the ignition and blow-out limits of the twin-plate flameholder are better than those of the single-plate and v-gutter ones. It is found that an S-shaped recirculation structure in the wake zone is formed behind the twin-plate flameholder due to the slit stream between the plates. The slit stream also improves the local propane fuel distribution within the wake region and enhances the flammability limit. This, in turn, results in an increase of the reversed mass and extends the lean ignition limit and the flame stability. It can be concluded that the slit stream introduced by the twin-plate flameholder is the controlling mechanism in improvement of aerodynamic mixing and increasing the concentration of fuel-air mixture in the recirculation zone. This is regarded as the special feature of the twin-plate type flameholder. This paper provides typical results and a guide for the design of this type of flameholders.
All Science Journal Classification (ASJC) codes