AcuTopoBlock

Generates nodal boundary conditions that are used as blockages for topology optimization run.

Syntax

acuTopoBlock

Type

AcuSolve Preparatory Program

Description

AcuTopoBlock is a utility program that uses the results from a topology optimization run to generate nodal boundary conditions that may be used to create solid blockage for a subsequent run. The utility is useful when the model has multiple inlets and outlets and the aim is to create separate fluid volumes that do not mix.

Parameters

The following parameters are supported:
help or h (boolean)
If set, the program prints a usage message and exits. The usage message includes all available options, their current values, and the place where each option is set.
problem or pb (string) [_undefined]
The name of the problem is specified via this option. This name is used to generate input file names and extracted surface file names.
file (string) [_undefined]
The nodal boundary condition file associated with block_file = _undefined [default].
design_level (real) [0.5]
A nodal boundary condition file is created to form a volume with design_level.
reverse (boolean) [FALSE]
A nodal boundary condition file is created to block outside of the design_level (larger than design level).
working_directory or dir (string) [ACUSIM.DIR]
All internal files are stored in this directory. This directory does not need to be on the same file system as the user-supplied input files.
run_id or run (integer) [0]
Number of the run in which the translation is requested. If run_id is set to 0, the last run in the working directory is assumed.
case_id or case (integer) [0]
Number of the case in which the translation is requested. If case is set to 0, the last case in the working directory is assumed. If the option levelset_cut = TRUE is used, the last case is always selected.
levelset_cut (boolean) [FALSE]
If levelset_cut is TRUE, levelset is used to generate the .nbc file for solid blockage instead of design topology.
levelset_level (real) [0]
This is an offset parameter to create a thickness of solid between the different fluid volumes if the levelset solution option is used (when levelset_cut = TRUE).
verbose or v (integer)
Set the verbose level for printing information to the screen. Each higher verbose level prints more information. If verbose is set to 0 (or less), only warning and error messages are printed. If verbose is set to 1, basic processing information is printed in addition to warning and error messages. This level is recommended. verbose levels greater than 1 provide information useful only for debugging.verbose= 1 [default].

Guidelines

AcuTopoBlock can create the .nbc file based on the computed design value in the simulation, or the levelset solution. If the levelset solution option is used, there is an offset parameter that may be used to create a "thickness" of the solid between the different fluid volumes.
Note: It is possible to repeat the process above if more than two volumes are computed. Multiple nodal boundary conditions files may be used.

To use level set instead of design topology:

levelset_cut = TRUE

The levelset offset is set by

levelset_level = 0.0

A possible workflow is as follows:
  1. Prepare a model with multiple inlets and outlets. Decide which volume to create first. Set the inlet flow boundary condition and outlet boundary condition for the first target volume, and make the inlet and outlet walls for the remaining inlets and outlets.
  2. Run the first topology flow optimization run to completion.
  3. Use AcuTopoBlock to generate the nbc for the second run.
  4. Set the inlet flow boundary condition and outlet boundary condition for the second target volume, and make the inlet and outlet walls for the remaining inlets and outlets. Include the .nbc file created by acuTopoBlock in a nodal boundary condition command for design_topology setting a constant value of 1.
  5. Run the second topology flow optimization run to completion.