Encyclopaedia Index

WORKSHOP - Multi-Block - 2

Un-natural Links

This workshop goes through the steps required to create a three-block grid with an un-natural link, using the GCV solver.

It will be helpful to be familiar with the basic steps of BFC grid generation, as shown in the other BFC tutorials.

Basic steps for Multi-Block Setup

  1. Plan the decomposition of domain into individual blocks. A possible configuration is shown above. Each block is to be 5 x 5 x 1.
  2. Generate the grid for each individual block. The grid for each block will be generated in a separate mesh-generator session.
  3. Combine the grids to form the multi-block grid and define inter-block links. This step involves hand-editing the input Q1 file.
  4. Define remainder of the problem (variables, boundary conditions, etc).

Hints for Problem Setup

Start

Create geometry for all blocks

Point x y z
P1 0 0 0
P2 1 0 0
P3 2 0 0
P4 2 1 0
P5 1 1 0
P6 2 2 0
P7 1 1.732 0
P8 0.5858 1.414 0
P9 0.2679 1 0
Name Type Joining points
L1 Straight P1 - P2
L2 Straight P2 - P3
L3 Straight P3 - P4
L4 Straight P4 - P5
L5 Straight P5 - P2
L6 Straight P4 - P6
L7 Straight P5 - P8
A8 Arc P1 - P9 - P8
A9 Arc P8 - P7 - P6

After the last line, click OK twice to return to the main BFC Menu dialog.

Set grid for first block

Set grid for second block

Set grid for third block

Combining the three blocks

TALK=T;RUN(1,1)

BFC=T

GCV=T

NUMBLK=3

READCO(UGRI+)

MPATCH(1,MBL1.2,WEST,2,2,1,NY-1,1,NZ,1,1)

MPATCH(2,MBL2.1,EAST,NX-1,NX-1,1,NY-1,1,NZ,1,1)

MPATCH(1,MBL1.3,NORTH,2,NX,NY-1,NY-1,1,NZ,1,1)

MPATCH(3,MBL3.1,SOUTH,2,NX,2,2,1,NZ,1,1)

MPATCH(2,MBL2.3,NORTH,1,NX-1,NY-1,NY-1,1,NZ,1,1)

MPATCH(3,MBL3.2,WEST,2,2,2,NY,1,NZ,1,1)

SPEDAT(SET,GCV,MBL3.2,C,WNL)

STOP 

Save and exit Notepad.

The READCO command reads the three block files and assembles them. The MPATCH commands link the three blocks.

These are the only operations which cannot be performed from a dialog box.

Setting up the remainder of the problem

Solution

Results

To view:

To select the plotting variable: