Instantaneous 3D-imaging of highly turbulent flames using Computed Tomography of Chemiluminescence (CTC)

The CTC technique was applied for the first time to a real highly turbulent swirl flame setup, using a larger number of CCD cameras (Nq = 24 views), to directly reconstruct the three-dimentional (3D) instantaneous and time-averaged checmilumienscence fields. The views were obtained from a 172.5o region (in one plane) around the flame, and the CTC algorithm (Floyd et al., Combust. Flame 158, 2011) was used to reconstruct the flame by discretising the domain into voxels. We investigated how the reconstructions are affected by the views’ arrangement and settings of the algorithm, and considered how the quality of reconstructions should be assessed to ensure a realistic description of the technique’s capabilities. The reconstructions using Nq  12 were generally better when the cameras were more equiangularly distributed. When Nq was severely low (e.g. 3), the reconstruction could be improved by using less voxels. The paper concludes with a summary of the strengths and weaknesses of the CTC technique for examining a real turbulent flame geometry and provides guidance on best practice.