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samina August 1, 2012 09:42

Most Efficient Numerical Method for Solving Boundary Layer Flows
 
hi friends,:)
Can anyone tell me about some efficient n stable numerical schemes to solve Boundary Layer Flow Problem. thanks
With profound regards.
samina
:)

leflix August 2, 2012 07:06

Quote:

Originally Posted by samina (Post 374836)
hi friends,:)
Can anyone tell me about some efficient n stable numerical schemes to solve Boundary Layer Flow Problem. thanks
With profound regards.
samina
:)

Hi Samina

which kind of boundary layer problem?
If it is 2D and over a flat plate, solving Blasius equation is straightforward.
check this :http://moon.pr.erau.edu/~gallyt/ae30...ricBlasius.pdf
If the geometry is more complex than flat plate, use any good Navier-Stokes solver.

samina August 2, 2012 12:48

thanks leflix,
you suggested a goood link.
My problem is not on an easy geometry, its the BVP for the flow over an expanding stretching cylinder, (in cylindrical coordinates) 3D geometry
:confused:

leflix August 2, 2012 13:14

Quote:

Originally Posted by samina (Post 375078)
My problem is not on an easy geometry, its the BVP for the flow over an expanding stretching cylinder, (in cylindrical coordinates) 3D geometry
:confused:

Then the only outcome is to solve the full NS equations. Refine the grid near the wall. Hope the Reynolds number is not too high....

samina August 4, 2012 11:20

One more issue,I have NS eq of order four, while i have only three boundary conditions..
What should i do for the missing condition.
Regards
:)

cfdnewbie August 4, 2012 11:43

Quote:

Originally Posted by samina (Post 375373)
One more issue,I have NS eq of order four, while i have only three boundary conditions..
What should i do for the missing condition.
Regards
:)

What kind of formulation of the NS equations do you have?? They are second order PDEs.... :confused::confused:

samina August 4, 2012 12:00

Obviously, 2nd order PDEs (NS eqs for the viscous fluid).
but when i convert these equations to ODE, by using similarity transform for the stretching surfaces, order of the differential equation is raised by 1, so it becomes 3rd order ODE.
And when i solve the same problem for the 2nd grade fluid, i get ODE of order 4
:confused:

cfdnewbie August 4, 2012 13:16

Quote:

Originally Posted by samina (Post 375375)
Obviously, 2nd order PDEs (NS eqs for the viscous fluid).
but when i convert these equations to ODE, by using similarity transform for the stretching surfaces, order of the differential equation is raised by 1, so it becomes 3rd order ODE.
And when i solve the same problem for the 2nd grade fluid, i get ODE of order 4
:confused:


Sorry, I don't know what a 2nd grade fluid is, but if you have 3 BCs from the similarity ( I assume what you are doing is similar to the classical blasius solution, which is a 3rd order PDE), then the last one has to come from this 2nd grade fluid, whatever that might be :)


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