COMPUTERIZED TOMOGRAPHY: A TOOL IN FLUID FLOW AND COMBUSTION DIAGNOSTICS

Computerized axial tomographic reconstruction technique (CAT) has been originally developed for X-ray medical applications. The technique is widely used to obtain cross-sectional pictures of living bodies, mapping not only their structures, but also some of their physiological functions. This technique is successfully extended to map chemical species concentration and temperature fields across reacting and non-reacting flows. The method has the capability of high speed (real-time), three-dimensional reconstruction of laminar and turbulent flow fields. In our paper, we present and review the convolution algorithm for tomographic reconstruction of a three-dimensional field from a set of corres-ponding two-demensional projections. The algorithm involves parallel beams geometry and multiangular laser-based absorption measurements. The effects of the choice of filtering functions together with the required number of viewing angles on the algorithm performance are demonstrated with the aid of simulation results of two axisymmetric functions similar to the profiles in fluid flow and combustion processes.