A211 Determination of water flow velocity around Ram Flameholder by PIV

This study deals with hydrodynamics phenomena around a ram flameholder in a water channel. The Particle Image Velocimetry (PIV) method has been used to get the velocity fields around two models of flameholders. The first model is a simple V-gutter and the second has the same shape with holes through its walls. We observed the same kind of phenomena with the two models of flameholders. Some vortices are alternately shed from both edges of the flameholder and rotate in opposite directions. But in the second model, the holes through its walls.induce jets that generate swirling motions inside the flameholder zone. These vortices perturb the flow pattern in the wake of the flameholder and induce a higher level of turbulence. As a result, this should improve the mixing fuel-air inside the flameholder zone and the combustion in the ramjet engine.