4 replies to this topic

[dhns]

Dear sirs,

Please, can any one explain the term Rho V^2?
Will this term cause major problems when line and vessel sizing ?
What is the need to consider this?

What are the general limitation ranges in the number?

Please Explain.

regards
dhns.

[JoeWong]

Rho V2 is typical measurement for momentum, indirectly the kinetic energy of moving fluid.

In many old design, many designer focus on velocity as major factor in kinetic energy. However, nowadays designer will take into account of fluid density as density also play important rule in defining the kinetic energy especially fluid carrying liquid, heavy metal, solid, etc.

In line, the kinetic energy is limited so that the vibration, erosion, corrosion, surge, noise, etc is within a "reasonable" range (subject to company and designer...). In gravity separator (believe your "vessel" mean separator), the kinetic energy is will distributed to reduce breakage of liquid phase, re-entrainment and allow sufficient time for gravity force to act on heavy component (liquid phase).

[sheiko]

dhns,

This term has the same unit as "pressure", i.e.: force by unit of surface or energy by unit of volume... think on it.

[dhns]

thanks Mr.joewong and Mr.Sheiko,
for your kind information,
Sheiko i have a little further confusion,The term Pressure indication the force applied in a unit area,but momentum deals about motion of fluid or body.
how those two are having same unit (i checked already both are same unit as per your explanation also so.)please Explain if possible.

Thanks,
Dhns.

[Andree]

rho * v^2 / 2 (as in Bernoulli eqn) is often called "dynamic pressure"... it expresses the pressure resulting from flowing fluid momentum