pmp77
Automotive
- Sep 25, 2008
- 2
Hello Everyone,
I try to make a simulation for the flow into a polyurethane mould tool. I use ANSYS ICEM CFD to create the grid and ANSYS CFX for preprocessing, solving and postprocessing , but I have encountered problems. The most important part is where the PU flows into the nest, there the thickness is about 0,5mm. Other crosssections change from 10 to 30mm.
Can anyone tell me how to make a proper grid for that?
Here is what I have tried:
1. I have choosen the deafault size of tetrehedras to give proper answer in the questionable area. The reasult was crash when reached 14 000 000 tetrahedras.
2. I tried to build a coarser grid, but it generates very bad grid at the inflow. Later refinement of the grid there did not help to improve the gird fitting to geometry.
3. I have built up a more simple model that has similar geometry but is quicker to calculate. I have split up the geometry to several bodies and made different size grids according to the crosssection. I managed to bulid up part by part answering "merge" when creating new grids. It seemed to work well. But when I put the result in the preprocessor I can not find the IN and OUT and WALL surfaces I have created.
4. I created a testtube in CAD. Put in CFD, created a homogenous grid, in, out and wall parts. then put in preprocessor. Worked well
5. I have cut this testtube into two and generated two grids while mergeing them at the same time. Added the two parts with the two girds; have wall, in and out surfaces, but in the preprocessor I can not find the in out and wall to create the boundaries.
I have tried to search google on the topic, tried the help and tutorials of the program, and finally this forum. If anyone would be so kind to help me solve this problem I would be very glad.
Thank you in advance.
pmp77
I try to make a simulation for the flow into a polyurethane mould tool. I use ANSYS ICEM CFD to create the grid and ANSYS CFX for preprocessing, solving and postprocessing , but I have encountered problems. The most important part is where the PU flows into the nest, there the thickness is about 0,5mm. Other crosssections change from 10 to 30mm.
Can anyone tell me how to make a proper grid for that?
Here is what I have tried:
1. I have choosen the deafault size of tetrehedras to give proper answer in the questionable area. The reasult was crash when reached 14 000 000 tetrahedras.
2. I tried to build a coarser grid, but it generates very bad grid at the inflow. Later refinement of the grid there did not help to improve the gird fitting to geometry.
3. I have built up a more simple model that has similar geometry but is quicker to calculate. I have split up the geometry to several bodies and made different size grids according to the crosssection. I managed to bulid up part by part answering "merge" when creating new grids. It seemed to work well. But when I put the result in the preprocessor I can not find the IN and OUT and WALL surfaces I have created.
4. I created a testtube in CAD. Put in CFD, created a homogenous grid, in, out and wall parts. then put in preprocessor. Worked well
5. I have cut this testtube into two and generated two grids while mergeing them at the same time. Added the two parts with the two girds; have wall, in and out surfaces, but in the preprocessor I can not find the in out and wall to create the boundaries.
I have tried to search google on the topic, tried the help and tutorials of the program, and finally this forum. If anyone would be so kind to help me solve this problem I would be very glad.
Thank you in advance.
pmp77
