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Calculation of pressure gradient in periodic boundary condition

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Old   May 12, 2011, 10:00
Exclamation Calculation of pressure gradient in periodic boundary condition
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Ksaati
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Hi
I am a student and i'm doing my project work in FLUENT. Simulation of flow over circular cylinder is to be done. Material is water. Computational domain is rectangular. inlet is taken as velocity inlet and outlet as pressure-outlet. Top and bottom boundary condition is periodic. how do i calculate pressure gradient which is necessary to input in transitional periodic condition? How do i get the value of period? Somebody kindly help me. It is extremely urgent.... Please help.
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Old   May 13, 2011, 03:00
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If you specify Mass Flow Fluent will calculate Pressure Gradient (see Fluent doc.)
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Old   May 13, 2011, 03:32
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Thanks for the reply.
I referred the FLUENT manual specifying the translationally periodic boundary condition. I would like to know whether in Fluent the Periodicity associated with the periodic boundary condition could be found out my any methods? If i gave pressure gradient as 0 for translationally periodic condition is there any error?? Please help me to find this. I'm a beginner in CFD.It is extremely urgent!!
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Old   May 13, 2011, 06:26
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With the periodic condition you compute the "fully-developed'' flow meaning infinite length (outlet=inlet) If you specify mass flow the value choose for the pressure gradient is the initial guess and will be update during calculation.
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Old   May 13, 2011, 07:10
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My problem is to get the periodicity associated with the boundary condition "periodic". Is there any option in FLUENT to calculate the periodicity associated with the boundary condition??
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Old   May 13, 2011, 08:35
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What do you mean exactly by "periodicity" ?
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Old   May 13, 2011, 12:31
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Actually I need to know whether it is possible to find the period T associated with the boundary condition. Is there actually any period associated with the boundary condition " PERIODIC" as the name suggests ? Thanks in advance
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Old   May 16, 2011, 04:59
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No, not any period is associated with the boundary condition " PERIODIC"
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