11.2.4. Critical Reynolds Numbers

Try these first

1. 1.

   What does the Reynolds number represent?

   Hint

   Think about the forces acting in fluid flow.

2. 2.

   At what Reynolds number does laminar flow transition to turbulent flow?

   Hint

   Remember the separation points for flow types.

3. 3.

   At what Reynolds number does laminar flow shift to turbulent flow?

   • 100,000
   • 1,000,000
   • 3,000,000

   Hint

   Think about the boundary conditions we discussed.

4. 4.

   True or False: The Reynolds number can indicate both laminar and turbulent characteristics.

   • True
   • False

   Hint

   Consider the reynolds number application in fluid dynamics.

5. 5.

   A fluid with a density of 1000 kg/m^3, dynamic viscosity of 0.001 Pa.s, and a velocity of 5 m/s is flowing over a length of 2 m. Calculate the Reynolds number and determine the type of flow.

   Hint

   Use the formula for Reynolds number carefully.

6. 6.

   A rectangular plate measuring 1 m by 0.5 m is submerged in water at 20°C with a viscosity of 0.001 Pa.s. If the top surface of the plate experiences a velocity of 2 m/s, calculate the boundary layer thickness at the end of the plate assuming it is a steady flow.

   Hint

   Research boundary layer approximations to derive the solution.