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Old   August 30, 2016, 16:34
Default Mesh generation
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Samraj Manickam Palvannan
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Hello all, I have some problems generating mesh for the attached picture. Its a flow simulation model. two inlets flow into a nozzle and the flow out through outlet. The gas from 2nd inlet flows around the 1st inlet and by the exit of 1st inlet, the gas from 2nd inlet mixes and flows out. I tried meshing but the gas from 2nd inlet dont just flow around 1st but just on the top the 1st inlet walls and move to right hand side of the model. Any help or guidance on how to approach the problem would really help me a lot. Thanks very much
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Old   September 6, 2016, 08:26
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Colinda
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Are you sure it is a meshing problem and not a boundary condition problem? If you already created a mesh, could be helpful to post a picture of it. And maybe to add some info about the boundary conditions applied at inlets and outlet

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Old   September 6, 2016, 12:10
Default Mesh generation - 2d picture
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Samraj Manickam Palvannan
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The dots represent the fluid volume domain. The fluid from second inlet, in green color, flows in, goes sround the first inlet and mix with fluid that comes out of first inlet.
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Old   September 12, 2016, 03:40
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Would be good to look at your boundary conditions: which (total) pressure levels and/or mass flows you are applying at the inlets and outlet.
Still also it would be good to show your mesh as both pictures only show the definition of the domain.
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Old   September 12, 2016, 09:18
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Samraj Manickam Palvannan
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Hello,
here is the oicture of the mesh i created for my problem.

The red colored mesh means ( from top towards -y direction), one gas enters into that at 40m/s, 323k and 3bar.

the blue colored mesh means air enters into that at 30m/s, 303k, 1 bar. both mix and get combusted in the blue colored mesh area after flowing in through their respective inlets. inorder to proceed with simulation, should i make these twi diff. meshes into one?

Thanks very much
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Old   September 12, 2016, 10:49
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Indeed if the fluid regions in reality are connected, you need to connect your two meshes as well. Otherwise the flows will never mix. At which location to connect them and which boundary condition to use, depends on the physics of your problem. Either a matching connection can be used if the grid is matching at the location to connect. Otherwise an interpolation technique is needed.

Btw, it seems to me your blue mesh is quite coarse though to simulate any mixing.
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Old   September 12, 2016, 10:55
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Samraj Manickam Palvannan
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Hallo
I understand that now. The fluids mix where the red colored mesh meets with blue colored one, ( in the picture, on x axis, where the L-shaped red colored mesh ends). The matching, i suppose I could do by choosing the same grid size around the area where both fluids meet.??

Thanks much
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