question in boundary layer?
 

hi dear friends
:confused:in one of posts that sent by user as written:
The definition of the boundary layer (wall boundary layer or free shear layer) says that the streamwise change is much smaller than the cross-stream change.
Where can I find resources for this? my mean is stream wise change is much smaller than cross stream, unfortunately i dont find reference for it.
please guide me
best regards

Maybe Prandtl theory?

dear antanas, i have look in prandtl theory but i dont find things in this case.
whether you have information in this case?

dear opaque
unfortunately i dont access to your link, if your possible and you access to springer, please send one image in this case.
thanks

I meant for you to read what is considered a mandatory reading on boundary layers.

You can find that book on the library of any university that majors in mechanical, aerospace, chemical, civil or related engineering degree.

You can also find similar statements on nearly any basic fluid mechanics book.

thanks dear opaque