Introduction to discretization - Part 1

[@lukasf2648]

I really like the theory part as well. It helps to understand what is going on. Thank you

[@OpenFOAMJozsefNagy]

I am glad you like it. In my opinion it is very important.

[@sandipgewali641]

At 2:00, where you compare general transport equation with convection-diffusion equation, you are assuming rho to be 1. But, doesn't that make the previous tutorial incompressible ?? But, we simulated shock-wave travel in that case. Do these two cases make sense with one another ??

[@OpenFOAMJozsefNagy]

You solve two different sets of equations. Here a simple scalar transport, for the shock wave the compressible Navier-Stokes equations.

[@sandipgewali641]

@@OpenFOAMJozsefNagy can't the scalarTransportFoam be classified as compressible or incompressible??

[@OpenFOAMJozsefNagy]

@@sandipgewali641 The simple scalar transport equation (which is implemented in OF) doesn't know anything about the density.

[@jeromepowelltoecrum6044]

At 10min, you say 50% are asleep, but after reading the wolfdynamics 120 pages of slides, 40 paages of gavin tabor slides and 3h of fvm videos from wolfdynamics I think this 10min of video at 1.25x speed doesn't seem too bad XD

[@sacramentofwilderness6656]

Thanks for your tutorials! Still actual, with minor modifications in 2020.

[@iranshad9081]

Thank you Sir, very good explanation.

[@shinshan5145]

Hallo Mr. Nagy. Thanks for that great explanation. Which disseration do you mean? I cant find any disseration by henrik yushin that you mentioned in your video for detail according the discretization. Thanks

[@OpenFOAMJozsefNagy]

Henrik Rusche

[@balajichandrasekaran6312]

Divergent scheme is only for Non orthogonal neighbour cells? Will the neighbour take the cosine of normal vector of previous cell & proceed further ?

[@OpenFOAMJozsefNagy]

div schemes are for all cells. They represent an important part of transport.

[@yem.t.3930]

Thank you Sir!

[@balajichandrasekaran6312]

I really like the theory part but i couldnt understand the linear upwind scheme how intermediate phase can have 2 values? based on previous slope?

[@OpenFOAMJozsefNagy]

you take the cell value and the gradient in that cell. depending on the flow you take the cell or the neighbor.

[@DaylightDigital]

Great work yet again!

[@Murilo08LOL]

Dear Professor Nagy, I was trying to reproduce those cases, however the oscillations that I am getting for the cubic and the linear cases are only visible when I set the limits on Paraview from -0.001 to 0.001. I checked and it seems that the models are the same. Do you know if there was any difference on the version of OpenFOAM? I am using version v1812 through Docker.

[@OpenFOAMJozsefNagy]

Newer versions are a bit more stable. This is OK.

[@Murilo08LOL]

@@OpenFOAMJozsefNagy Thank you very much! All the best!

[@OpenFOAMJozsefNagy]

@@Murilo08LOL Thank you!

[@akkadiansummer466]

Amazing! Very good!

[@hoomanenayati]

Well done! Thank you :)