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Tim September 5, 2001 11:13

Curved pipe in cylindrical-polar
as part of the problem I am trying to solve I need to simulate the flow in a curved pipe. Ideally I would like to do this in cylindrical-polar coordinates. However, I am having difficulty in generating the geometry. I can easily build a curved rectangular duct using a polcub.dat file, but I can not seem to find a way to produce a curved pipe. Is it possible to do this in the VR editor or do I have to go to an outside source to do the geometry and import it into the VR editor?

Any suggests would be greatly appreciated, Tim

Richard September 18, 2001 03:28

Re: Curved pipe in cylindrical-polar
How do you make your curved rectangular duct using a polcub.dat file in cylindrical-polar coordinates ? How do you want to make the curved pipe ? In my guess, you can use cylindrical.dat to creat the curved pipe .

Tim September 18, 2001 11:02

Re: Curved pipe in cylindrical-polar
The curved rectangular duct is easy. When you stretch the polcub.dat in the x-dirction, it causes the walls of the cube to take a curved shape. However, when you stretch the cylindrical.dat geometry the straight walls of the cylinder remain straight, they do not curve along the x-direction. Secondly, the polcub.dat file is very different then the cube.dat file, because of the different coordinate system. The cube.dat only needs 8 nodes and 6 faces, whereas the polcub.dat has 84 nodes and 82 faces, as it really is a series of cubes that gives it the curved shape along the x-axis. I known that I could, if I had the time and patience, to code a curved tube into a .dat file, but it is just not economical. I am looking for an alternative to doing this.

Richard September 19, 2001 05:22

Re: Curved pipe in cylindrical-polar
Actually you still can use the cylindrical.dat to creat the curved pipe in physical model nowhether it is presented as a curved pipe in VR. The *.dat may would be considered as the showing data in VR but not actually directly effect the physical model. If you would like to creat the curved pipe as you want to see. There are some ways to do.

1. Directly input several segments of adjacent cylindrical.dat object. 2. Modified the cylindrical.dat file to creat a new polycylind.dat file by interpolating some coordinates sets between the one at z=0 & the one at z=1 also don't forget the arrangement of facet # and color code. 3. Creating the polycylindrical by CAD STL formated file. 4. Creating the polycylind directly by Shapmaker in PHOENICS version 3.4. (It is the most convenient way)

Tim October 1, 2001 14:39

Re: Curved pipe in cylindrical-polar
Thanks Richard, I solved the problem by creating a CAD STL file in AutoCAD where I set the FACETRATIO to a value of 1, FACETRES to 10, thus creating an object with multiple facets in each direction and it works very will when imported into PHOENICS.

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