Simultaneous reconstruction of temperature and concentration profiles of soot and metal-oxide nanoparticles in asymmetric nanofluid fuel flames by inverse analysis

An inverse analysis based on the flame emission spectrum technique is presented for the simultaneous reconstruction of two-dimensional (2D) temperature and concentration fields of soot and metal-oxide nanoparticles in the asymmetric nanofluid fuel flames by means of CCD cameras. Four CCD cameras located around the flame cross-section were used to capture the line-of-sight flame emission radiation intensities which were disintegrated to determine the radiation emission source by Least Squares QR algorithm (LSQR) algorithm. The flame cross-section was uniformly divided into several sub-squares with various grid numbers and the relationship between the grid number and the reconstruction precision was investigated in details. Considering the tradeoff between reconstruction resolution and accuracy, the optimal grid number was chosen to be 10 × 10. Satisfactory estimate of the three unknown fields obtained even with the signal to noise ratio of the measurement system as low as 46 dB. Numeral analyses show that the proposed reconstruction method is effective and robust for concurrent reconstructing the temperature and concentration profiles of soot and metal-oxide nanoparticles in the asymmetric nanofluid fuel flames.