Pumps and Bernoulli's equation

[fog37]

TL;DR Summary

understanding how pumps work

Hello,

My understanding is that pumps (whatever type) add energy to the fluid and cause the fluid to move. The fluid can be either brought to a higher elevation or not.

I am unclear on how pumps "provide a larger pressure". Do they? If so, in what sense? Are pumps simply speeding up, i.e. increasing the kinetic energy, of the fluid (gas or liquid) that is pulled inside the pump case and the pressure increase discussed with pumps is nothing but the increase in "dynamic pressure" that the fluid would experience at if brought to rest at a stagnation point after it exist the pump?

 

[russ_watters]

My understanding is that pumps (whatever type) add energy to the fluid and cause the fluid to move. The fluid can be either brought to a higher elevation or not.

Typically it is said that pumps apply or create a pressure, which causes a fluid to move, similar to how you would say you apply a force to a box to push it across the floor.

I am unclear on how pumps "provide a larger pressure". Do they? If so, in what sense?

Two most common methods are pistons, which directly push on the fluid and centrifugal, which actually use a combination of centrifugal force from spinning the fluid and a hydrodynamic lift effect (like a wing).

Are pumps simply speeding up, i.e. increasing the kinetic energy, of the fluid (gas or liquid) that is pulled inside the pump case and the pressure increase discussed with pumps is nothing but the increase in "dynamic pressure" that the fluid would experience at if brought to rest at a stagnation point after it exist the pump?

You get both an increase in static and dynamic pressure.

 

[gmax137]

In a centrifugal pump, the impeller increases the velocity of the fluid - kinetic energy. The fast-moving fluid then passes through the diffuser or volute, which has a larger exit area. This slows the fluid; the kinetic energy is "converted" to pressure.

 

[ShellScot]

Understanding the cutting of said "Impeller" is a whole profession in itself. Berkley Sta right have been doing this foreva. To learn impellers, their unique physics will provide a step up in fluid dynamics as a whole...
Possibly contact someone at those Companies. They may be able to provide plethora of solid information..
Sheldon