speed of fluid and turbulence

[215353]

---

Members do not see this ad.

Lets say you have a tube and it has a larger cross-sectional area at one end compared to the other end...

obviously the speed of the fluid at the smaller cross-sectional end of the tube will be faster to maintain constant flow rate (says the continuity equation).

my question is, if the speed of the fluid is increased at the smaller cross-sectional area is the fluid passing through that smaller cross-sectional area more turbulent as well?

thanks

 

[redlight]

i may be wrong but i think "turbulent" almost implies changes in things like speed, direction/path/motion, etc...turbulent imo implies something not uniform and not consistent...changes in things like pressure and velocity.

if that's the case, then i dont think "turbulent" is the right adjective. the water is moving faster but it is also probably more uniform...more smooth

im thinking of water being poured out of a funnel. the funnel streamlines the process so the water comes out at a quicker but static and smooth rate.

 

[ChemEngSoonMD]

Lets say you have a tube and it has a larger cross-sectional area at one end compared to the other end...

obviously the speed of the fluid at the smaller cross-sectional end of the tube will be faster to maintain constant flow rate (says the continuity equation).

my question is, if the speed of the fluid is increased at the smaller cross-sectional area is the fluid passing through that smaller cross-sectional area more turbulent as well?

thanks

read the first book on the left, and 12th book from the left. You are welcome.

 

[ezsanche]

read the first book on the left, and 12th book from the left. You are welcome.

most of these books i bet you didn't even read. lol

 

[Hemichordate]

read the first book on the left, and 12th book from the left. You are welcome.

Yo ChemE, did you go to Berkeley?

 

[ChemEngSoonMD]

Yo ChemE, did you go to Berkeley?

No, but my GF did. I went to University of Washington. They got a pretty good med program.

To the other guy, you are probably right. Between starcraft, diablo2, and 3 jobs, who has time to read all that ****?

 

[215353]

can anybody else offer any advice? there is no time to read extra material right now btw doing secondaries, etc. This is a something i've been struggling to understand hence why I asked it on this forum. This is place where it is encouraged to ask MCAT questions so that we can help each other. I would appreciate it if I could receive that help.

thank you

 

[ezsanche]

can anybody else offer any advice? there is no time to read extra material right now btw doing secondaries, etc. This is a something i've been struggling to understand hence why I asked it on this forum. This is place where it is encouraged to ask MCAT questions so that we can help each other. I would appreciate it if I could receive that help.

thank you

When dealing with turbulence, there is something called the reynolds number that gives you an idea if flow will become turbulent. The higher the reynolds number the more likely the flow will be turbulent and hence the flow will be chaotic producing vortices, eddies, and other types of fluctuations.

The equation is

Re= (v x L)/u

where v is the velocity of the fluid
L is the length of the object that the flow is going through
u correlates to viscosity.

So as you can see, high fluid velocity tends to increase the Reynolds number which makes turbulence more likely. However as you can also see from the equation, velocity is not the only thing that affects turbulence. So even if a fluid has high velocity if it going through a small length section or if the viscosity of the fluid is high enough then it might not be turbulent after all.

 

[redlight]

When dealing with turbulence, there is something called the reynolds number that gives you an idea if flow will become turbulent. The higher the reynolds number the more likely the flow will be turbulent and hence the flow will be chaotic producing vortices, eddies, and other types of fluctuations.

The equation is

Re= (v x L)/u

where v is the velocity of the fluid
L is the length of the object that the flow is going through
u correlates to viscosity.

So as you can see, high fluid velocity tends to increase the Reynolds number which makes turbulence more likely. However as you can also see from the equation, velocity is not the only thing that affects turbulence. So even if a fluid has high velocity if it going through a small length section or if the viscosity of the fluid is high enough then it might not be turbulent after all.

ahh, i like this explanation! my next attempt was going to be turbulent vs laminar flow.