- #1
AppeltjeBosheuvel
Good afternoon,
I find it hard to understand friction velocity, shear stress, momentum and temperature scale. For a class, we are using MOST dimensionless analysis to find values of intensity for the turbulence. However, I'm struggling with the terms.
What exactly is friction velocity u*? My book only states it is a velocity scale.
I read online it is the same as shear velocity, when shear stress is rewritten in units of velocity (I assume so it is easier to make a dimensionless analysis later). But what exactly is shear stress though? Is is the stress of the resistance between a fast and slow moving air layer when it comes to turbulence? I find it hard to understand.
Functions given are u* = squareroot(surface shear stress)/density = squareroot(-u'w')
Where does the square root come from?
What exactly is T* temperature scale and q* moisture scale of water vapor?
I'm super confused. Thanks already!
I find it hard to understand friction velocity, shear stress, momentum and temperature scale. For a class, we are using MOST dimensionless analysis to find values of intensity for the turbulence. However, I'm struggling with the terms.
What exactly is friction velocity u*? My book only states it is a velocity scale.
I read online it is the same as shear velocity, when shear stress is rewritten in units of velocity (I assume so it is easier to make a dimensionless analysis later). But what exactly is shear stress though? Is is the stress of the resistance between a fast and slow moving air layer when it comes to turbulence? I find it hard to understand.
Functions given are u* = squareroot(surface shear stress)/density = squareroot(-u'w')
Where does the square root come from?
What exactly is T* temperature scale and q* moisture scale of water vapor?
I'm super confused. Thanks already!
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