Passive scalar flux measurements in the near-field region of a swirling jet

The present experimental investigation is devoted to the heat flux characteristics of a passive scalar in the near-field region of a swirling jet issuing from a fully developed axially rotating pipe flow. A combined X-wire and cold-wire probe made it possible to access the instantaneous streamwise and azimuthal velocity components as well as the temperature simultaneously. Results indicate that the addition of swirl increases the integral scales and entrainment and thereby the streamwise passive scalar flux and shortens the distance and hence time needed to mix the jet with the ambient air.