Abstract
Characteristics of reattachment and blowout of laminar lifted flames in partially premixed jets of propane fuel have been investigated experimentally. As flow rate decreased from a lifted flame, liftoff height decreases nonlinearly and the flame reattached to a nozzle at a certain liftoff height. By using the similarity solutions for jets by taking into account the virtual origins for both velocity and concentration, it has been predicted that the flow velocity along a stoichiometric contour has a maximum value. From this velocity behavior, a flame reattachment can be successfully explained based on the balance between the propagation speed of a tribrachial flame and flow velocity. Predicted displacement speeds during reattachment and liftoff agreed well with experiment. With improved accuracy in the velocity and concentration solutions accounting the virtual origins, conditions at reattachment and blowout as functions of jet velocity, fuel mass fraction, axial distance, and nozzle diameter can be more accurately predicted compared to those without considering virtual origins.