How to scale the ABL velocity profile?

pela145 · February 5, 2016, 06:34

Hi all!

I am modelling the flow around a high rise building. I use the ABL and I have been using 1:1 scale since I started. However, I would like now to reduce my model to a 1:400 scale and I should reduce my ABL logaritmic velocity profile as a consequence.

However, since it is not a linear velocity profile, maybe the reduction could not be exactly proportional. I mean, if I used Zref=10 and Uref=10, maybe the reduction wouldn't be Zref=0.1 and Uref=0.1, but Uref=0.08, or something like that, since it is a logaritmic profile instead of a linear profile.

I know that the easier way would be to use linear reduction and forgeting about it. But I would like to do a good work.

I hope you could provide me some information about it.

Thanks in advance.

Pelayo

Ahmed Hassan · November 15, 2017, 08:28

Hello pela145;
i have the same problem as you, did you find a solution for it ?

February 5, 2016, 06:34	How to scale the ABL velocity profile?	#1
pela145 New Member Join Date: Oct 2015 Location: Oviedo, Asturias, España Posts: 17 Rep Power: 11	Hi all! I am modelling the flow around a high rise building. I use the ABL and I have been using 1:1 scale since I started. However, I would like now to reduce my model to a 1:400 scale and I should reduce my ABL logaritmic velocity profile as a consequence. However, since it is not a linear velocity profile, maybe the reduction could not be exactly proportional. I mean, if I used Zref=10 and Uref=10, maybe the reduction wouldn't be Zref=0.1 and Uref=0.1, but Uref=0.08, or something like that, since it is a logaritmic profile instead of a linear profile. I know that the easier way would be to use linear reduction and forgeting about it. But I would like to do a good work. I hope you could provide me some information about it. Thanks in advance. Pelayo

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November 15, 2017, 08:28		#2
Ahmed Hassan New Member Ahmed Hassan Join Date: Nov 2017 Posts: 10 Rep Power: 8	Hello pela145; i have the same problem as you, did you find a solution for it ?