11.3. Applications and Examples

Try these first

1. 1.

   Define wall stress and its relevance in fluid mechanics.

   Hint

   Think about how fluids interact with surfaces.

2. 2.

   What is the significance of shear stress in fluid flow?

   Hint

   Consider the forces acting parallel to a surface.

3. 3.

   What does wall stress refer to in fluid mechanics?

   • Stress on the liquid surface
   • Stress exerted by fluid on boundaries
   • Internal stress in fluids

   Hint

   Consider the interaction between fluid and wall.

4. 4.

   Is vorticity present in irrotational flow?

   • True
   • False

   Hint

   Understand the characteristics of irrotational flow.

5. 5.

   A fluid flows between two parallel plates with a velocity gradient of 5 m/s per meter. Calculate the shear stress if the dynamic viscosity of the fluid is 0.8 Pa.s.

   Hint

   Identify the parameters needed for shear stress calculation.

6. 6.

   A pipe has an acute angle bend, and water flows through it at varying velocities. Explain how average velocity through a cross-section at the bend can be computed.

   Hint

   Think of how you might find the average height of a group of students.