The intention of this paper was to demonstrate the principle and usefulness of computed tomography for concentration field measurements. Radial extinction coefficient profiles have been reconstructed using the LTD approach in the transition region of an isothermal jet of air at Reynolds number of 2 600. Reconstructed profiles were compared against velocity profiles at axial distances ranging from 2 to 20 nozzle diameters downstream. Results indicate that the width parameter of the reconstructed scalar distribution is around 23 % larger than the velocity distribution for distances between 10 and 20 nozzle diameters downstream. This finding is in good agreement with the results of other investigators. This technique has evidently yielded an accurate description of the scalar field of the round isothermal free jet.

The quality of the reconstructions is very promising considering the relatively few measurement data, projection angles and low pixel resolution used in this study.

Ccomputed tomography is superior for monitoring chemical concentrations over larger areas (whole room) when PMS and PLIF are unfeasible.