Question

Question 1: (true or false)

a- It is unnecessary to account for surface forces when writing the momentum equation for control volume (True) (false)

b- in the course of Fluid Mechanics, we studied fluid on the ‘continuum’ not the ‘atomistic’ level. (True) (false)

c- Bernoulli’s equation can be appropriately applied for flow through machinery, such as a turbine, compressor, or mixer. (True) (false)

d- The Reynolds number balances pressure with viscose force.(True) (false)

e- The Reynolds number has the dimension of force. .(True) (false)

f- Flow similarity is achieved when the flow are geometrically similar, kinematically similar, dynamically similar, and in the same flow regime. (True) (false)

Answer 1

a. FALSE

b.TRUE because It is a branch of continuum mechanics, a subject which models matter without using the information that it is made out of atoms; that is, it models matter from a macroscopic viewpoint rather than from microscopic.

c. FALSE The Bernoulli Equation is an energy balance (PV energy + kinetic energy + gravitational energy) from one place to another. Pumps add energy and turbines remove energy, so the energy balance doesn’t balance.

d. FALSE it balances inertia force to viscous force.

e. FALSE reynolds number is dimensionless.

f. TRUE In order to have complete similarity between the model and prototype, all the similarity flow conditions must be maintained