1.10. Kinematic Viscosity Ratio

Try these first

1. 1.

   What is the Froude number a ratio of?

   Hint

   Remember what dominates in scenarios involving gravity.

2. 2.

   Define dynamic similarity.

   Hint

   Think about the conditions necessary for accurate model testing.

3. 3.

   What must be equal for both a model and prototype if gravity is the dominant force?

   • Froude number
   • Reynolds number
   • Kinematic viscosity ratio

   Hint

   Think about which forces dominate in a gravity-driven flow.

4. 4.

   True or False: The Reynolds number is used to compare the effects of viscous forces in fluid flow.

   • True
   • False

   Hint

   Focus on the forces involved in fluid mechanics.

5. 5.

   A hydraulic engineer is designing a model of a new bridge over a river. If the prototype's Froude number is 4 and the model must match it while simulating conditions in a lab, how should the engineer scale the model length to achieve this?

   Hint

   Reflect on the mathematical relationships between Froude numbers and dimensions.

6. 6.

   Given a prototype with kinematic viscosity of 0.001 m²/s and density of 1000 kg/m³, what is the necessary kinematic viscosity for a model that has a different density of 800 kg/m³ to maintain a similarity in scale?

   Hint

   Keep in mind how viscosity ratios and densities interact in flow.