Image reconstruction of flow field for supersonic separator based on model modification and algorithm optimization of ECT
Precision measurement of flow field parameters in a supersonic separator is essential for optimizing its structure and performance.Electrical capacitance tomography(ECT)offers a non-invasive approach to accurately measure these parameters.The mathematical model for solving the inverse problem of ECT is mainly obtained by linearization approximation,which ignores the influence of nonlinearity and"soft field"effect on the image reconstruction.As a result,the image reconstruction is of poor quality when the dielectric constants of the media in the field differ significantly.Aiming at the problem,the mathematical model of the ECT inverse problem was modified by introducing the model derivation error.Then,based on the separable property of the objective function,a solution algorithm combining regularization and Split Bregman(RASB)was designed to solve the model error and the media to be reconstructed by cross iteration.The image reconstruction results of the RASB algorithm,Tikhonov regularization algorithm,L1 regularization algorithm and Landweber algorithm for several models using simulation and experimental data showed that the proposed method could reduce the error generated by the linearization approximation,and weaken the effect of noise on the image reconstruction.The RASB algorithm could reconstruct more accurate media distribution with fewer artifacts in the image,and the average correlation coefficient of the reconstructed images was 0.8964,which was higher than that of the Tikhonov regularization algorithm(0.8353),the L1 regularization algorithm(0.8496),and the Landweber algorithm(0.8681).
supersonic separatorelectrical capacitance tomographymodel derivation errorsregularization and Split Bregmancross iteration