3D Instantaneous Reconstruction of Turbulent Industrial Flames Using Computed Tomography of Chemiluminescence (CTC)

Abstract

Computed Tomography of Chemiluminescence (CTC) was used to reconstruct the instantaneous three-dimensional (3D) chemiluminescence field of a high-power industrial flame, which was made optically accessible, for the first time. The reconstruction used 24 projections that were measured simultaneously, in one plane and equiangularly spaced within a total fan angle of 172.5°. The 3D results were examined by plotting both vertical and horizontal slices, revealing highly wrinkled structures with good clarity. The results presented are one of a series of experimental demonstrations of CTC applications to turbulent gaseous flames. The work reveals the potential to use any kind of luminescence measurement, such as emission from heated particles in coal-fired flames, for analysis of the flame shape directly in 3D.

Two-Dimensional Tomographic Simultaneous Multispecies Visualization—Part II: Reconstruction Accuracy

“…To the best of our knowledge, the work of Anikin et al [3,4] is so far the only study that uses Tikhonov regularization for the tomographic imaging of laminar and turbulent flames. The vast majority of tomographic studies on combustion processes uses either the algebraic reconstruction technique (ART) [6,7,[10][11][12][13][14][15][16][17]19,20,23,28,29,60] or its sibling, the multiplicative algebraic reconstruction technique (MART) [21,22,25,26,[30][31][32]. ART was developed independently by Gordon, Bender and Herman [49] and Hounsfield [50].…”

3D Evolutionary Reconstruction of Scalar Fields in the Gas-Phase

“…In the last decades 3D computed tomography (CT) methods have seen widespread use in numerous areas of engineering and physical sciences research. The methods have combined CT with various different measurement techniques such as laser absorption spectroscopy [1][2][3], schlieren [4,5], chemiluminescence [6][7][8][9][10][11][12][13][14][15][16][17] and particle image velocimetry [18,19]. Generally, projection measurements that are obtained at different angles around the probed volume are used for reconstructions.…”

“…For solving a discrete formulated inversion problem in the form of a linear system of equations, iterative methods were developed, such as the algebraic reconstruction technique (ART) [21]. Diverse variants of the ART were established for computed tomography of chemiluminescence (CTC) [6,8,9,[11][12][13][15][16][17].…”

“…Additionally, a calibration free reconstruction method is feasible with this method by optimizing the cameras parameters simultaneously while reconstructing. This is generally not possible for our CTC method [8,9,16,17], as the matrix to be inverted is formed in a one-time ray-tracing step.…”

“…Furthermore, we present experimental reconstructions of these flames using a multi-camera setup. The camera setup was tested in previous experiments [16,17] and we compare the ERT results to ART-based reconstructions using a CTC method [8,9] that features an advanced camera model.…”