Multi-State Phenomena and Hysteresis of Counterflow Flame over Tsuji Burner

This investigation focuses on flame hysteresis in a porous cylindrical burner. This hysteresis is caused by different operating procedures of the experiment. Gradually increasing inflow velocity can transform the envelope flame into a wake flame. The blow-off curve is plotted by determining every critical inflow velocity that makes an envelope flame become a wake flame at various fuel-ejection velocities. In contrast, reducing the inflow velocity can transform the wake or lift-off flame into an envelope one. The reattachment curve can be obtained by the same method to explore the blow-off curve, but the intake process is reverse. However, these two curves are not coincident, except at the origin. The discrepancy between them is called hysteresis, and it results from the difference between the burning velocities associated with both curves. At the lowest fuelejection velocity, no hysteresis exists between two curves because the difference between burning velocities is almost zero there. Then, raising the fuel-ejection velocity enhances hysteresis and the discrepancy between the two curves. However, when the fuel-ejection velocity exceeds a critical value, the intensity of hysteresis remains almost invariant and causes the two curves parallel to each other.