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In the Control Parameters frame allows the user to set various parameters relating to the plume entrainment. The user can set the #Elements, which is the maximum number of vertical computational elements along the length of the jet or plume. The entrainment calculation is an iterative process, the maximum number of iterations to be made if convergence is not obtained is set in the #Iterations form.
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Other options include setting for the Entrainment Error Criteria, is a factor used in the iterative solution, and an adjustment factor for the Froude Number. EFDC can also write out a log file in various formats. Specify 1 for full ASCII, 2 for compact ASCII output at each update, 3 for full and compact ASCII output, and 4 for binary output.
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Figure 2 Thermal Discharge from Multiport Diffusers using Jet/Plume BC.
Jet/Plume Sub-model
The Jet/PIume sub-model in EFDC is partly described in EPA's "Review of potential modeling tools and approaches to support the BEACH program." Here this sub-model is described as providing a buoyant jet near-field dilution and mixing zone sub-model that is incorporated directly into the EFDC. The model simulates single-port and merging multi-port discharges using a three-dimensional extension of the Lagrangian formulations used in the UM model (Baumgartner et al.. 1994) and the JETLAG model (Lee and Cheung. 1990). The jet/plume model is unique in its use of unsteady fully three-dimensional ambient velocity density and concentration fields and realistic bathymetry for trajectory, entrainment. and dilution calculations. For multi-port discharges the merging of individual port plumes into multiple coalesced plumes is simulated. In addition to simulating the near-field and far-field concentration of dissolved contaminants, jet/plume sub-model simulates sediment transport and the transport and fate of sorptive contaminants including the settling and bed exchange of the suspended and sorbed material (note that water quality parameters are not simulated at this stage).
The Jet/Plume sub-model automatically updates multiple outfalls as ambient conditions and outfall discharges evolve in time. The near-field solution is automatically coupled to the EFDC model's far-field transport and fate simulation, allowing the ambient concentration field to represent the historical influences of all unsteady discharges. The Jet/Plume sub-model is particularly well suited to near-shore coastal simulations. The hydrodynamic component of the EFDC model is capable of simulating unsteady tide-wind- and wave-driven currents including long-shore and across-shore currents associated with incident wave transformation and surf zone wave breaking.