The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

Guangqian Wang - One of the best experts on this subject based on the ideXlab platform.

  • Concentration Distribution of contaminant transport in wetland flows
    Journal of Hydrology, 2015
    Co-Authors: Zi Wu, Xudong Fu, Guangqian Wang
    Abstract:

    Summary Study on contaminant transport in wetland flows is of fundamental importance. Recent investigation on scalar transport in laminar tube flows (Wu and Chen, 2014. J. Fluid Mech., 740: 196-213.) indicates that the vertical Concentration difference in wetland flows may be remarkable for a very long time, which cannot be captured by the extensively applied one-dimensional Taylor dispersion model. To understand detailed information for the vertical Distribution of contaminant in wetland flows, for the first time, the present paper deduces an analytical solution for the multi-dimensional Concentration Distribution by the method of mean Concentration expansion. The solution is verified by both our analytical and numerical results. Representing the effects of vegetation in wetlands, the unique dimensionless parameter α can cause the longitudinal contraction of the contaminant cloud and the change of the shape of the Concentration contours. By these complicated effects, it is shown unexpectedly that the maximum vertical Concentration difference remains nearly unaffected, although its longitudinal position may change. Thus the slow-decaying transient effect (Wu and Chen, 2014. J. Hydrol., 519: 1974-1984.) is shown also apply to the process of contaminant transport in wetland flows.

Ping Wang - One of the best experts on this subject based on the ideXlab platform.

  • lateral Concentration Distribution of contaminant transport in tidal wetland flows
    Journal of Hydrology, 2020
    Co-Authors: Ping Wang, Zhiqiang Zhang
    Abstract:

    Abstract Tidal flows, in addition to the vegetation, introduce considerable complexity into the transport of contaminants in wetland flows. Under the hypothesis that wetlands can be treated as porous media, we apply the phase averaging technique to obtain the apparently continuous Concentration Distribution at the macro phase-average scale in tidal wetland flows, rather than the extremely complex Concentration Distribution at the micro plant scale. To meet the requirements of precise Concentration in terms of peak Concentration position and value for strict environmental and health risk assessments, this work studied the lateral Concentration Distribution rather than the generally studied approximate longitudinally distributed mean Concentration. The lateral Concentration functions for tidal wetland flows are concretely derived to support the first-order series expansion of the generalized dispersion model. We show that the lateral Concentration nonuniformity can be qualitatively altered as the contaminant cloud is carried back upstream by tidal flows. The peak Concentration position periodically appears at the center line or at the wall depending on the tidal flows, and the peak Concentration value can even be increased in the transport process. Due to its analytical features, this work provides a model with low computational cost for effective environmental management.

  • Concentration Distribution of environmental dispersion in a wetland flow extended solution
    Journal of Hydrology, 2017
    Co-Authors: Weiquan Jiang, Ping Wang, G Q Chen
    Abstract:

    Abstract Hydrological processes of contaminant transport in wetland flows are characterized by environmental dispersion. For Concentration Distribution of scalar dispersion, the preliminary estimate of vertical Distribution (Wu et al., 2015) on small time scale is rigorously extended to account for high order effects as skewness and kurtosis. Based on a combination of Aris’ method of Concentration moments and Gill’s generalized dispersion model, up to fourth order terms of vertical Distribution functions and full-time two-dimensional Concentration Distribution are derived. The increments of damping factor, mainly representing the density of vegetation in wetlands, is shown to strengthen the mean Distribution asymmetry and reduce the longitudinal dispersivity (with respect to skewness and kurtosis), and to increase the non-uniformity of vertical Distribution. Therefore, dense vegetation corresponding to a large damping factor will postpone the time when Taylor’s dispersion model holds, and the first order approximation becomes rough on small time scale, demanding higher order modifications. The results provide more detailed and more accurate analytical solution for the typical environmental dispersion in wetland flows.

Riccardo Buccolieri - One of the best experts on this subject based on the ideXlab platform.

Zi Wu - One of the best experts on this subject based on the ideXlab platform.

  • Concentration Distribution of contaminant transport in wetland flows
    Journal of Hydrology, 2015
    Co-Authors: Zi Wu, Xudong Fu, Guangqian Wang
    Abstract:

    Summary Study on contaminant transport in wetland flows is of fundamental importance. Recent investigation on scalar transport in laminar tube flows (Wu and Chen, 2014. J. Fluid Mech., 740: 196-213.) indicates that the vertical Concentration difference in wetland flows may be remarkable for a very long time, which cannot be captured by the extensively applied one-dimensional Taylor dispersion model. To understand detailed information for the vertical Distribution of contaminant in wetland flows, for the first time, the present paper deduces an analytical solution for the multi-dimensional Concentration Distribution by the method of mean Concentration expansion. The solution is verified by both our analytical and numerical results. Representing the effects of vegetation in wetlands, the unique dimensionless parameter α can cause the longitudinal contraction of the contaminant cloud and the change of the shape of the Concentration contours. By these complicated effects, it is shown unexpectedly that the maximum vertical Concentration difference remains nearly unaffected, although its longitudinal position may change. Thus the slow-decaying transient effect (Wu and Chen, 2014. J. Hydrol., 519: 1974-1984.) is shown also apply to the process of contaminant transport in wetland flows.

G Q Chen - One of the best experts on this subject based on the ideXlab platform.

  • Concentration Distribution of environmental dispersion in a wetland flow extended solution
    Journal of Hydrology, 2017
    Co-Authors: Weiquan Jiang, Ping Wang, G Q Chen
    Abstract:

    Abstract Hydrological processes of contaminant transport in wetland flows are characterized by environmental dispersion. For Concentration Distribution of scalar dispersion, the preliminary estimate of vertical Distribution (Wu et al., 2015) on small time scale is rigorously extended to account for high order effects as skewness and kurtosis. Based on a combination of Aris’ method of Concentration moments and Gill’s generalized dispersion model, up to fourth order terms of vertical Distribution functions and full-time two-dimensional Concentration Distribution are derived. The increments of damping factor, mainly representing the density of vegetation in wetlands, is shown to strengthen the mean Distribution asymmetry and reduce the longitudinal dispersivity (with respect to skewness and kurtosis), and to increase the non-uniformity of vertical Distribution. Therefore, dense vegetation corresponding to a large damping factor will postpone the time when Taylor’s dispersion model holds, and the first order approximation becomes rough on small time scale, demanding higher order modifications. The results provide more detailed and more accurate analytical solution for the typical environmental dispersion in wetland flows.