Boundary Layer displacement thickness

AI Thread Summary
The discussion focuses on understanding the boundary layer displacement thickness, represented by δ*, which affects streamlines near a wall. The formula for δ* is given as δ* = ∫(1 - u/U) dy, applicable for flow over a plate. The user seeks to find the equation of the streamline at the plate's end (x=4m) where y equals δ^b. There is confusion regarding the calculation of boundary layer displacement thickness and its implications for the streamline equation. Clarification on the mathematical interpretation of δ = δ^b is also requested to facilitate further assistance.
VooDoo
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Hey guys,


The streamlines just outside a boundary layer are pushed away from the wall by the displacement thickness \delta* and I understand that;

\delta*=\int^{\infty}_{0}(1-\frac{u}{U})dy

Now this is for flow over a plate with length x=4m. At x=0 is the leading edge and at x=4 \delta = \delta^{b}

Now been told to find the equation of the streamline i.e. y=y(x) that touches the boundary layer at x=4 (and y = \delta^{b} I guess).

I know I have to calculate the boundary layer displacement thickness...but I am unsure of how to do that and what I should do after that.
 
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delta = delta ^ b is a mathematical inequality? Therefore if you rewrite the problem literally from your homework a bit more clearly I might be able to help you with this one.
 
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