Shear stress resistance

The shear stress resistance (or friction resistance ) is the force on a body in a flow, which arises from the shear of the fluid adhering to the surface . The size of this force depends on the size of the affected surface and the flow conditions, especially on whether the flow is laminar or turbulent : turbulent flows increase the wall shear stress , laminar flows reduce it: ${\ displaystyle F_ {w}}$ ${\ displaystyle A}$ ${\ displaystyle \ tau _ {w}}$

{\ displaystyle F_ {w} = A \ cdot \ tau _ {w}}

The shear stress resistance , together with the pressure resistance, forms the total resistance of a body in flow.

To reduce the shear stress resistance, laminar profiles are used in gliders which, with a particularly large thickness reserve (thickest point of the profile around the middle instead of around the front quarter), maintain a laminar flow as long as possible. The aerodynamic quality of these profiles is heavily dependent on the nature of the surface: even raindrops , condensation , dirt or insects can significantly increase the air resistance .

Individual evidence

^ Cord-Christian Rossow; Klaus Wolf; Peter Horst: Handbook of aircraft technology . Carl-Hanser-Verlag, Munich, ISBN 978-3-446-42341-1 , pp. 85-86.

[1] Cord-Christian Rossow; Klaus Wolf; Peter Horst: Handbook of aircraft technology . Carl-Hanser-Verlag, Munich, ISBN 978-3-446-42341-1 , pp. 85-86.