Bed Temperature and Heat Exchange

Initial Conditions Bed Temperature frame, and the Bed Heat Exchange Coefficients frame are shown below. The last of these have been moved from the Settings button in releases prior to EE8.2.

The EFDCPlus version of the model has two different approaches for the bed heat sub-models. If the standard EFDC full heat balance (ISTOPT(2)=1) sub-model is used, the water/sediment bed heat exchange model of the pre-GVC version is used. If the user has selected the equilibrium temperature sub-model (ISTOPT(2)=4) then the bottom heat exchange is computed using the heat exchange coefficient and the user can assign spatially varying sediment thicknesses and initial temperatures using the TEMB.INP file.

Note that the EFDC_GVC model uses a thermal bed model to determine the bed/water column heat exchange (Tetra Tech, 2007c). A sediment thermal thickness is assigned for the entire model. This thickness is not related to either the sediment transport model's bed or the water quality sediment bed. This thermal layer is then divided into KBH layers (must be >2). A constant initial bed temperature can be used or alternatively the TEMPB.INP file can be used to assign a spatially variable initial temperature, by layer. Check the Use Spatially Variable Bed Temp and Thickness checkbox in the Initial Conditions - Bed Temperatures frame for this option.