AITCH
Flow in an H-Shaped Region

AITCH is a FORTRAN90 program for flow in an H-shaped region.

More specifically, AITCH is intended to model the geometry needed for a time-dependent flow of an incompressible fluid in a 2D region, under the Navier Stokes equations.

This program is simply an initial sketch of how to divide up the the region in a way that makes it possible to generate a consistent account of the nodes and elements needed to implement a finite element representation of the solution.

Source Code:

• aitch.f90, the source code.
• aitch.csh, commands to compile the source code.

Examples and Tests:

• aitch_output.txt, the output file.
• aitch_node.eps, an EPS image of some of the nodes.
• aitch_node.png, a PNG version of the image.
• aitch_element.eps, an EPS image of some of the elements.
• aitch_element.png, a PNG version of the image.

List of Routines:

• AITCH tests the AITCH geometry routines.
• AITCH_DOF_NUM determines the number of degrees of freedom in the region.
• AITCH_ELEMENT_NODE determines the nodes that make up each element.
• AITCH_ELEMENT_NUM determines the number of elements in the region.
• AITCH_NODE_DOF_SET assigns degrees of freedom to each node.
• AITCH_NODE_NUM determines the number of nodes in the region.
• AITCH_NODE_XY assigns coordinates to each node.
• ELEMENT6_EPS creates an EPS file containing an image of the mesh.
• ELEMENT_NODE_BANDWIDTH determines the bandwidth associated with the grid.
• ELEMENT_NODE_PRINT prints the elements.
• GET_UNIT returns a free FORTRAN unit number.
• NODE_DOF_INDEX_PRINT prints the nodal degrees of freedom.
• NODE_EPS creates an EPS file containing an image of the nodes.
• NODE_XY_PRINT prints the node coordinates.
• TIMESTAMP prints the current YMDHMS date as a time stamp.
• TIMESTRING writes the current YMDHMS date into a string.