Improving Computed Tomography of Chemiluminescence under Projection Angle Limitations via Camera Layout Optimization

High-quality bulk tomography imaging under limited projection angle conditions is an important challenge in complex flow and combustion diagnostics. Aiming at the problem that only a few high-speed cameras can usually be deployed in supersonic wind tunnel experiments due to limited optical access, this paper proposes a camera layout optimization method that combines computed tomography of chemiluminescence (CTC) technology with fiber-optic endoscopes (FBEs). The method reduces the correlation of the projected weight matrix and data redundancy by maximizing the angle between the subspaces of the rows of the weight matrix, thus improving the reconstruction accuracy and stability. Combined with the geometric characteristics of the wind tunnel with multiple windows, the simulated annealing algorithm is used to optimize the projection angle and spatial distribution of the camera to maximize the capture of effective information. Numerical simulation and experimental results show that, compared with the traditional circular plane uniform layout, the average cross-correlation coefficient of the verified projections is above 0.98, which is about 2.1% higher than that of a uniform layout, effectively suppressing reconstruction artifacts caused by limited projections. This optimization method reduces the reconstruction error of finite projection angles and exhibits good adaptability and robustness to changes in flame direction.