Navier Stokes

[Robert Edmonds]

Just wondering if you have heard of the term, and know how it's related to weather.

 

[Stuart Wilson]

Brings me out in a cold sweat to think about the Navier-Stokes equation after all this time. My final year project (22 years ago!) was looking at improving the CFD modelling of turbulence. Back then the programs were written in Fortan, compiled overnight and then run. So if you'd written quite a bit of code it often took a whole week to debug and actually get a clean run. I used to have a tape with it all on - about the size of a frisbee.

 

[Jason Foster]

I voted:

I have never heard of it.

for the record.

 

[Greg Blumberg]

I learned that it was the whole "Navier-Stokes Equations of Motion for the Zonal and Meridional." Zonal being East-West, Meridional being North-South.

I'm pretty sure the Navier Stokes equations come from fluid dynamics and relates to both the conservation of momentum and Newton's 2nd Law in fluids.

Also wanted to mention that on the poll: "recite" is misspelled.

 

[Robert Edmonds]

Also wanted to mention that on the poll: "recite" is misspelled.

Yea I saw that shortly after I posted the poll. I couldn't find a way to change that... I also forgot to put the "-" in Navier-Stokes.

Back then the programs were written in Fortan, compiled overnight and then run.

Many programs I run into are still written in Fortran. Hey, at least we're not still using punch cards!

 

[Patrick Marsh]

Where's the option "I've had to code-up the darn thing"...?

 

[David Wolfson]

Hey, don't bash FORTRAN! Years ago I compiled and linked for VAX/VMS a simulation program with over 650 subprograms and 70k lines of code, written by accretion over about 20 years. Took about a week. AFAIK it had never been ported to VMS. Try that with your C++ or Python, you young whippersnappers !

 

[Jeff Passner]

Oh, I've actually heard of them... Aren't Navier and Stokes a comedy team on ABC??? Okay, I'm rusty but I know this term all too well.

 

[Jason Bolt]

Navier Stokes. Isn't he a second baseman for the Devil Rays?

 

[John Peters]

currently in school, so I eat sleep and breathe Navier Stokes and its variants.

 

[Cris Schroeder]

Navier-Stokes pretty much defines fluid dynamics. I don't know how the equations are used specifically in meteorology, but we use them regularly in aerodynamics. The NS codes take a long time to run, and the results depend a lot on what turbulence model you use. NS can in theory fully define fluid motion but you still have to make a lot of assumptions in your boundary conditions to keep the run time reasonable. They sure make some pretty pictures, though!

 

[Dan Dawson]

The N-S equations aren't just used in Meteorology, they are absolutely the backbone of Meteorology. Most of the equations used in Meteorology are derived in some form from the N-S equations, with various simplifying assumptions for a given situation. In fact, I can't really think of an area of study in Meteorology that doesn't derive its functional equations at least in part from the N-S equation set.

And, yes, Fortran is awesome, and rumors of its death are greatly exaggerated. Pretty much every single NWP model out there is written largely in Fortran, and I don't see this changing anytime soon.