# BCFLOW: A Post-Processor for Calculating Boundary Flow Rates and Cumulative Amounts from HST3D Simulations -- Version 2

# Introduction

Version 2 of the HST3D simulator calculates flow rates and cumulative amounts of fluid, heat, and solute for each boundary cell for each type of boundary condition. These values are written to a file, `Bcnfr.`*xxx*, for post-processing whereby total flow rates and cumulative amounts can be calculated for a set of boundary-face subareas selected by the user. In the HST3D simulator, the trapezoidal rule is used for temporal integration of the flow rates to obtain the cumulative amounts.

The flow rates and cumulative amounts are segregated by boundary-condition type: specified value, specified flux, leakage, evapotranspiration, aquifer-influence function, and heat conduction. They are further segregated by fluid mass, fluid volume, heat, and solute as the transported quantities. The final segregation is by the user-specified facial area zones.

The program BCFLOW does the summations of total flow rates and cumulative flow amounts for zones of cells forming boundary facial areas selected by the user. Version 2.5 of BCFLOW is designed to work with Version 2.2 of the HST3D simulator.

The BCFLOW program reads the boundary-node flow-rate output file, `Bcnfr.`*xxx*,
generated by HST3D for a given simulation, and a data file defining the zones of facial areas of boundary cells for which total flow rates and cumulative flow amounts of fluid, heat, and solute are desired. Then, the program totals the flow rates and cumulative amounts over the boundary nodes for the specified zones of boundary cells.

## Limitations

Quantities for only one type of boundary condition per zone of boundary facial area can be summed. At present, BCFLOW cannot maintain separate sums for the same type of boundary condition on two or three faces of the same cell. All quantities of a given boundary-condition type for every boundary face of a given cell are combined to form a net summation. Quantities associated with wells are not recognized in Version 2.5 of the BCFLOW program.

URL:
http://wwwbrr.cr.usgs.gov/projects/GW_Solute/hst/pages/bcflow_abs_2.shtml

Contact:klkipp@usgs.gov

Last modified: 22 Jun 2005