calculating water flow out of a pipe and predicting its flow pattern

[ctenophors rule]

I am doing a critical analysis on the physics of the EAC in finding nemo.

what i am trying to do is prove mathematicaly why it is impossible for water to remain in the cylindrical flow pattern with the conditions provided. (speed, density, etc)

I am having trouble finding/ adapting a formula to fit my needs.

so far i have looked into the reynolds number (hoping to be able to encorporate friction of water on water and somehow calceling out the pipe, didnt work for me)

I found this website http://www-pord.ucsd.edu/~wryoung/GFD_Lect/eddyDiffChpt.pdf but i am not sure if i am interpreting it correctly.

I think i would need to find the greens function, but how would one apply ocean to ocean flow into the equation? If this is the correct way to solve the equation, please tell me, and i will gie up now for this is way out of my league.

thanks guys...

*edit*

a thought occured.

can i just use the reynolds number for flow in piping (considering the ocean surrounding the current to be the pipe radius) and use the data collected from the movie for the initia. then set a time for the final (say five seconds) plug in the distance and subtract the finals from initial. whats left over will be the water that would have escaped from the current, causing it to loose form.

 

[GatorEngineer]

Are you talking about the part where the turtles are riding the currents?
Your thought seems reasonable for something simple but the movie is just a movie. Those currents are real but they just made them tubular to relate them to kids going through a water slide or roller coaster...
It's impossible for any liquid to hold a shape without a container so under no circumstance except fully-flowing through a pipe would water be completely cylindrical...and even then...
Is this for a class or fun?

 

[amonchak]

Fluid flow through a pipe has a velocity profile where the max velocity is at the center and the edges (where the water and pipe interface) the velocity is ~0. This being said if you were assuming that the EAC was contained by something the flow would not be cylindrical.

Another thought is if the flow is laminar or turbulent, if the flow is turbulent the flow be more random and not cylindrical.

 

[greenbean36191]

Eek. What you're proposing to figure out is a problem for an upper-level oceanography grad student. Geostrophy and zonal variation in wind speed and the Coriolis force form your "pipe" that hold the current together. At the frontal boundary you have Kelvin-Helmholtz instability (what your link seems to be trying to model) causing turbulent mixing at the edges of the current. The stratification and geostrophic balance of the current also lead to meander and mesoscale eddy formation which introduce another layer of turbulence. Trying to figure out how much water is lost to turbulence even over a short length is incredibly complicated and I doubt I would even be able to model it well having actually had to learn this stuff.

Using the Reynold's number calculation will simply tell you that the flow is turbulent, which we know from the onset since there are eddies and because the current doesn't accelerate indefinitely (and because large-scale ocean flow is turbulent as a rule).

This book might help, but it's written at a graduate level so can get pretty complicated. Chapters 7, 8, 10, 11, and 12 are the ones really relevant to your problem. http://oceanworld.tamu.edu/resources/ocng_textbook/contents.html

 

[ctenophors rule]

yes i have talked with my physics teacher this math is way above my tenth grade alg 2 math education. He is allowing me to adapt the project and use the Hazen-Williams equation. he says that the data wont be perfect, but as long as i explain the limitations of it the project will be fine.

Gator engineer, It is for a class. i was allowed to pick the movie and identify a situation in which the physics doesn't equal the outcome, however i didn't think finding nemo would be so difficult.

amonchak. why wouldn't the flow be cylindrical if contained in a cylindrical pipe? wouldn't the water conform to the shape of its containor?

Greenbean- thank you so much for that resource! That will help me so much for ocean bowl next year!