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Time Varying Boundary Conditon

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Old   February 14, 2005, 17:18
Default Time Varying Boundary Conditon
  #1
ashish
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Hi all,

This bit is interesting.

I have a problem of time varying boundary condition. I have a function on as boundary condition which varies with time. Say function = sin(5*time). When i write it down in CEL it gives error that it is unable to compute the function "time"? Why so ? and if so .. how can i give a function varying with respect to time on boundary only. Many thanks, Ashish
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Old   February 14, 2005, 18:00
Default Re: Time Varying Boundary Conditon
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Glenn Horrocks
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Hi,

In the documentation, under the CEL expression language it describes the variables and their name for use in CFX. You will find the variable name for time is "t". Note it is case sensitive.

Glenn Horrocks
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Old   February 14, 2005, 21:31
Default Re: Time Varying Boundary Conditon
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ashish
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Hi Glenn, I have tried that option but it gives some error with a message that it is unable to compute "t". regards ashish
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Old   February 15, 2005, 07:21
Default Re: Time Varying Boundary Conditon
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Rui
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Hi,

In CEL expressions I use the variable "t" and it works. I think you get an error because the sine argument must have angular units, and when you create an expression sin(5*t) the argument unit is [s]. So you have to do sin(5*t*1 [rad]/1 [s]), or if you want the period to be 1/5 [s] : sin(5*t*2*pi [rad]/1 [s])

Regards,

Rui
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