Erratum to “Measurement of Principal Permeability With the Channel Flow Experiment”

Weitzenböck et al. have proposed a theoretical framework for permeability estimation in two- and three-dimensions using a set of channel (1-D) flow experiments.[1] For determining the 2-D permeability tensor, three channel flow experiments must be conducted, whereas for estimating the 3-D permeability tensor, six unidirectional channel flow experiments along six unique orientations need to be performed. The authors have noted important errors in the above-mentioned widely-cited research article.[1] Here we highlight the errors involved in the theoretical derivation of the 3-D permeability tensor and report the corrected forms of the expressions for the tensor components. In Section 4.2 of Weitzenböck et al.,[1] based on the Direction of Permeability Measurement, there are two errors. These errors are related to the incorrect rotation angles of the measurement direction as follows: first, the rotation of the measurement direction by about the -axis for finding out the effective permeability , and second, the rotation of the measurement direction by about the -axis for finding out the effective permeability . Note that although the newly proposed rotation angle () is different from the original rotation angle (), the new expression for the effective permeability for turns out to be the same as given by Equation (22) in Weitzenböck et al.[1] Note that the expressions given for tensor components in Equations (3–8) are different from that given in Appendix B of Weitzenböck et al.[1] On comparing the two sets of expressions, the differences can be noted in the numerical coefficients of the numerator terms in the off-diagonal components and the value of constant . The interested readers can find the complete details of the derivation and validation of the modified permeability estimation approach in Appendix A of Raizada.[2]