Coupling with Other Solvers

Description and Quick Guide

A long term Flow Simulator development goal is to improve coupling with other solvers. Coupling Flow Simulator with other solvers can greatly increase the detail and scope of problems that can be modeled.

For Instance, Flow Simulator can be coupled with a full 3D CFD solver such as Acusolve (AS). Flow Simulator can be used to model the 1D part of the problem (like a piping network), and AS can be used to model parts of the problem that do not have 1D solutions (like flow through a nonstandard junction or valve).

Another example is coupling Flow Simulator with a full 3D thermal solver such as OptiStruct. Flow Simulator can be used to calculate flowrates and pressure through the advection network elements of the OptiStruct thermal model.

A file-based coupling option has been introduced in Flow Simulator, version 2021.2. This method will be improved in future versions, but it can be used effectively as is.

File-Based Coupling

This method automatically reads a file called FS_coupling.dat if it exists in the model directory. Nothing must be done in the GUI or the .flo file for this file to be used by the Flow Simulator solver. This file contains rows of data that describe information used to set boundary conditions at the beginning of the Flow Simulator solver run and retrieve data at the end of the Flow Simulator solver run.

The Flow Simulator coupling method uses the controller get and set capabilities so a wide range of items can be included in the coupling file. Here is a sample coupling file:

The DIRECTION column with “TO_FS” indicates the properties that are set at the beginning of the run and with the “FROM_FS” indicates properties retrieved from Flow Simulator at the end of the run. Flow Simulator will scale the VALUE based on the UNITS column. Flow Simulator will ignore any columns that it does not recognize. For example, the AS_ID column could be used by the other solver to identify a boundary condition input.

An example of the coupling file can be found in: