13.7.1. One-Seventh Power Law

Try these first

1. 1.

   What is the One-Seventh Power Law?

   Hint

   Think about how fluid velocity behaves near a surface.

2. 2.

   Define displacement thickness.

   Hint

   Consider how layers of fluid interact with surfaces.

3. 3.

   What does the One-Seventh Power Law approximately describe?

   • Velocity profile in laminar flow
   • Velocity profile in turbulent flow
   • Pressure distribution in a pipe

   Hint

   Think about where turbulence is most relevant.

4. 4.

   True or False: Displacement thickness pertains to the lost mass flow in a boundary layer.

   • True
   • False

   Hint

   Consider how layers of fluid alter flow characteristics.

5. 5.

   Given a flat plate in a turbulent flow, calculate the displacement thickness if the free stream velocity is 10 m/s at a point where the velocity profile shows 7 m/s at a distance of 0.5 m from the plate. Assume necessary values for Kinematic viscosity.

   Hint

   Remember to account for the velocity deficit in your formula.

6. 6.

   Explore how changing the surface roughness of an object affects the boundary layer characteristics and the applicability of the One-Seventh Power Law.

   Hint

   Think about how rough surfaces influence flow dynamics and behavior.