[Mirza]

Hi!
I am new here and in the world of CFD
i have questions please
1- why we use often the vorticity-velocity formulation than the primitive one (in 2D)

2-I read that the uwpind sheme is more accurate for solving the primitive formulation of NSeqs. why?

thank you
Best regards

[FMDenaro]

Originally Posted by Mirza

Hi!
I am new here and in the world of CFD
i have questions please
1- why we use often the vorticity-velocity formulation than the primitive one (in 2D)

2-I read that the uwpind sheme is more accurate for solving the primitive formulation of NSeqs. why?

thank you
Best regards

1) Actually, I don't see such formulation very often...the stream function-vorticity is often used for 2d, laminar flow because you solve only 1 parabolic equation and the elliptic equation for the stream function has boundary conditions that make faster the convergence than the pressure equation.

2) Your statement is not correct. Accuracy depends on the type of the discretization and is not related to upwinding.

[Mirza]

1- yes i wanted to say stream-vorticity, thank you.

2- the same when we have a big Re (the convection term dominated)??

[Mirza]

any help please?

also could you give me some books or paper to read for beginners?
thank you

best regards

[FMDenaro]

you can find the main titles in this forum, for example the book of Peric & Ferziger

[The_Provost]

Introduction to Computational Fluid Dynamics by John Anderson is a classic beginner's text book.

[davidwilcox]

To clear your doubts pertaining to the upwind scheme, try looking up the peclet number.