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Boundary ConditionHi,
I need to simulate the water flow in a circular pipe. I have some doubts about the outlet boundary condition. I have five options: velocity; pressure, no viscous stress; pressure; no viscous stress and normal stress. Someone can explain me the difference between the various options and what is the best option for my problem. There are also the option boundary stress instead of outlet boundary, with this boundary condition I can choose "normal stress, normal flow". What is the difference between boundary stress and outlet boundary? For the inlet boundary I can give the normal inflow velocity or the velocity field. I have same doubts about the choice of the inlet boundary, I think that I have to choose the velocity field, is that a good choise? Someone can help me? Where can I find information on these subjects? Thank you... |

Dear CC,
Using CFD you will solve Navier-Stokes for this problem. How would you define the boundary conditions if you were to solve a set of differential equations describing your problem? How would you estimate whether viscous forces are important to your model equations? (hint: http://en.wikipedia.org/wiki/Reynolds_number ) Without trying to discourage you, I think you should consider reading a general book on fluid dynamics. I dont know what software package you are using for your simulation, but surely there will be tutorials or a manual available for this type of problem. Best of luck! Graham |

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