On the treatment of lens optical center uncertainty in simultaneous reconstruction of flame temperature and soot volume fraction distributions by a CCD camera

In general, when charge-coupled device (CCD) cameras are used to reconstruct key flame parameters via inverse radiation analysis, the uncertainty of the camera lens optical center will introduce difficulties for practical applications and also reduce the reconstruction accuracy. This paper investigated the effect of the camera lens optical center location on the accuracy for concurrently reconstructing the distributions of temperature and soot volume fraction in an optically thin, axisymmetric flame with a single CCD camera via inverse radiation analysis. The impact of the ray number and measurement error on the precision of reconstruction was analyzed. Overall, the measurement error played a crucial role in reconstruction accuracy while the increase of the ray number could improve the reconstruction accuracy. When the lens optical center used for reconstruction was inconsistent with the actual one, the reconstructed errors can remain in an acceptable range. In summary, the effect of the lens optical center uncertainty on the reconstruction accuracy could be small. The conclusion obtained here can be useful for the practical reconstruction process.