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ACTUAL Velocity profile in the viscous layer

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Old   March 20, 2014, 04:07
Cool ACTUAL Velocity profile in the viscous layer
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Can anyone sum up all the differences in actual velocity profile (not the normalized one) when a "log-law" wall condition is applied to if it had been a theoretical laminar or turbulent profile here ?
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Old   March 20, 2014, 04:50
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in the viscous sublayer you get a laminar profile, very different from the log-law as it behaves like u+=y+
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Old   March 20, 2014, 05:17
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No. I am talking about y+ <30.....where both laminar and turbulent exist. What I would like to know is how this normalized log-law eqn....u+ = (y+ / k) + c gets plotted in a u v/s. y plot, not u+ v/s. y+......and also if I could get a plot of our well known turbulent and laminar profiles on the same plot, it would be very helpful because I want to compare all the three....for ex:- which one stays up or goes down for how long.....Please assume any relevant value for k and c above to give me this plot ?
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Old   March 20, 2014, 05:24
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Quote:
Originally Posted by Ankur Sawhney View Post
No. I am talking about y+ <30.....where both laminar and turbulent exist. What I would like to know is how this normalized log-law eqn....u+ = (y+ / k) + c gets plotted in a u v/s. y plot, not u+ v/s. y+......and also if I could get a plot of our well known turbulent and laminar profiles on the same plot, it would be very helpful because I want to compare all the three....for ex:- which one stays up or goes down for how long.....Please assume any relevant value for k and c above to give me this plot ?

just assume to know u_tau and the viscosity of the fluid, you can transform the laws (u+,y+) in (u,y)...
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Old   March 20, 2014, 05:34
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Yes....sure.Thank you Mr. Denaro
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