Simultaneous Estimation of Relaxation Time and Diffusion Coefficient during the Rapid Transient Mass Transfer

摘要

The Laplace transform method in conjunction with the least-squares scheme and the experimental data of the concentration history is used to predict the diffusion coefficient and the relaxation time during the rapid transient mass transfer of NaCl diffusing in H{sub}2O. Thus the non-Fickian diffusion equation is investigated. The diffusion coefficient and the relaxation time at a specific time can be obtained from the knowledge of the transient concentration recordings at a certain measurement location. In order to evidence the accuracy of the present inverse method, a comparison of the concentration history between the calculated results using the obtained estimates and the experimental data is made for various measurement locations. The results show that the history of the calculated concentration agrees with the experimental data.