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Old   September 7, 2013, 07:06
Default Doubts in catalytic convertor tutorial
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Kishore
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Dear all

I have question in the catalytic converter tutorial.
In the Global initialization tab they have introduced w= -2.8 m/s.
Why in the tutorial the negative sign has been introduced instead of 2.8 m/s?

I Need your help

Thank you
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Old   September 8, 2013, 06:29
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Glenn Horrocks
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Because the flow is in the negative w direction. Isn't that obvious?
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Old   September 8, 2013, 11:03
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Quote:
Originally Posted by ghorrocks View Post
Because the flow is in the negative w direction. Isn't that obvious?
If you are saying flow is in the negative w direction then input velocity may be negative sign (-25 m/s). then why the normal speed will be positive 25m/s ? is the normal speed means modulus of the velocity?

Thank you

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Old   September 8, 2013, 19:33
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When you define velocity at an inlet you just specify the magnitude. But for the initial condition you specify the full velocity vector. Hence the initial conditions is w=-2.8m/s, but the inlet is as positive number.
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Old   September 10, 2013, 11:16
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Quote:
Originally Posted by ghorrocks View Post
When you define velocity at an inlet you just specify the magnitude. But for the initial condition you specify the full velocity vector. Hence the initial conditions is w=-2.8m/s, but the inlet is as positive number.
It is very useful

Thank you so much
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