A211 Determination of water flow velocity around Ram Flameholder by PIV

Abstract

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.

A136 PIV measurements of high speed air flow in the wake of a flameholder

“…Some vortices are shed alternately from either edge of the flameholder and rotate in opposite direction. But contrary to the previous experiments in water (2), some small vortexes appear on the outline of the main eddies ( fig. 2).…”

“…of the combustion. The first step of this study consisted in the test of PIV method in a close-loop low-speed water channel downstream of a flameholder (2). The water flow measurements provided useful information for the improvement of the combustion performances and emission characteristics of ram combustor, in spite of experiments at lower Reynolds number.…”