Influence of self-absorption on reconstruction accuracy for temperature and concentration profiles of soot and metal-oxide nanoparticles in asymmetric nanofluid fuel flames

摘要

The inverse reconstruction method for the simultaneous estimation of temperature and concentration fields of soot and metal-oxide nanoparticles in asymmetric nanofluid fuel flame was improved by considering the self-absorption. The correction method to deal with the self-absorption in axisymmetric sooting flame for obtaining the unattenuated radiation intensity from the attenuated one detected by CCD camera was successfully extended to apply in asymmetric nanofluid fuel flame. These combustion parameters distributions can be concurrently deduced from the knowledge of the unattenuated radiation intensity using least-square QR (LSQR) decomposition and iterative methods. Self-absorption influences on the reconstruction accuracy in flames with different optical thicknesses were investigated and various levels of measurement errors were added into the simulation values from the practical experiment standpoint. The numerical results showed that the relative reconstruction errors of all the unknown parameters fields greatly reduced if self-absorption was considered in the reconstruction method. Moreover, as for the flame with larger optical thickness, the improvement of reconstruction accuracy was more significant.