Register to reply 
Lagrangian and eulerian descriptions of phenomena... 
Share this thread: 
#1
Oct1408, 09:54 AM

P: 374

hello everyone,
some differential equations are written in terms of a field perspective, some from the point of view of a particle moving through the field.... Navierstokes eqns can be derived from Newton' s 2nd law applied to a particle. What advantage is there in viewing things from a particle point of view( Lagrangian view)? I guess classica mechanics is based on this view. 


#2
Oct1408, 12:25 PM

Sci Advisor
P: 5,513

The two viewpoints are equivalent, but some problems are easier to write down in one particular choice of coordinates. For example, if you want to describe the flow of fluid through a channel, IIRC the Lagrangian viewpoint means you pick a control volume dV and watch the fluid flow through it (i.e. stand on the river bank and watch a static point in space), while the Eulerian view means you choose a fluid element dv and watch it deform over time (i.e. follow a material point in time).
In continuum mechanics, especially fluid mechanics, the Eulerian description is preferred because it's a more natural way to describe how deformation and flow carry momentum and energy, by using the total derivative D/Dt =[itex]\frac{\partial}{\partial t} + v\bullet \nabla [/itex]. 


#3
Oct1708, 12:04 PM

P: 151

Isn't it the other way around? Euler stays put, while Lagrange moves around with the particle?



#4
Oct2008, 02:09 AM

P: 1

Lagrangian and eulerian descriptions of phenomena...
I found that connector you were looking for
Cindy, is this the thing you were looking for? www.liangdianup.com/computeraccessories_1.htm It's on the list of computer accessories and parts. They have the DVI video thing to convert that jap monitor to work with your other computer. Just about any other kind of wire adaptor, usb connectors, monitor extension wires, ps2 extention wires, and all kinds of female and male swap connectors and things that I think would help your shop. If that above link don't work then goto www.lducompany.com and click on computer accessories. Let me know if that is what you need and give me your email address again. 


#5
Oct2208, 07:54 AM

Sci Advisor
P: 5,513




Register to reply 
Related Discussions  
Gauge theory (alternative descriptions)  General Physics  9  
Going from Eulerian Velocity to Lagrangian motion  Calculus & Beyond Homework  13  
Help with Lagrangian to Eulerian transformation  Differential Geometry  1  
FQXi project descriptions now online (thx GL)  Beyond the Standard Model  0  
Descriptions in physics  General Physics  4 