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Parameters in Mflow_02 moveable bed computations

  • Dec 13 2021
  • bowtiemrh


I was wondering if I could get a more detailed explanation than is given in the solver manual of how to properly set the parameters of the moveable be computations in the Mflow_02 solver. Specifically:
– How is the relative weight of bedload material calculated?
– What is the void ratio of the bed material? I see formulas online that give void ratio as, e=V_void/V_total. So is the proper interpretation of this parameter as the degree of soil compaction? How is this parameter utilized in the computations?
-Also, I am not sure what the morphological factor and the secondary flow coefficient and do not see a reference to these in the solver manual.



  1. mineyukigamou says:


    We will answer some questions. All are input data, but please refer to the following.

    The relative weight of bedload material is calculated by s = (σ⁄ρ-1).
    ρ: Water density
    σ: Gravel density (≅2.65)

    The void ratio of the bed material is typically 25-30%. For details, refer to the survey results of each analysis target area.

    The secondary flow coefficient is generally around 7.
    For more information
    “Engelund, F .: Flow and Bed Topography in Channel Bend, Jour.of Hydr.Div., ASCE, Vol.100. HY11, pp.1631-1648, 1974.”
    Please refer to.


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