16.4.1. Given Data for Laminar Flow

Try these first

1. 1.

   What is shear stress and how is it calculated?

   Hint

   Think of how forces are distributed over an area.

2. 2.

   Define Reynolds number.

   Hint

   Remember the ratio it represents.

3. 3.

   What is the definition of shear stress?

   • A force that resists fluid motion
   • Pressure exerted on a surface
   • The force per unit area applied parallel to a surface

   Hint

   Think of how force is applied on surfaces.

4. 4.

   True or False: The Reynolds number is used to predict both turbulence and viscosity in fluids.

   • True
   • False

   Hint

   Recall what Reynolds number measures.

5. 5.

   A cylindrical object of radius 0.25 m is submerged in a fluid with a viscosity of 0.002 Pa.s and moving at 4 m/s. What is the Reynolds number, and how would you classify the flow?

   Hint

   Use given parameters to substitute into Reynolds number formula.

6. 6.

   In a testing scenario, a model car has a frontal area of 0.02 m² and a drag coefficient of 0.3. If tested at a velocity of 25 m/s, how much drag force can we estimate on the full-scale car with a frontal area of 1.2 m²?

   Hint

   Don’t forget to scale the drag coefficient for practical use.