The CFD Bible

[Vyssion]

Hi guys,

So I wanted to share something with you that has been somewhat of a long term project of mine for a couple of years now... I bought a nice notebook a while back now, with the intent to save its pages for knowledge that I gained in my professional career and personal study and learning. I would write my scribbled workings on a separate booklet, and if there was something in there which was of particular interest, I would study it further, and then write up a passage explaining it within my little book.

Well, as of yesterday, I filled the last of the ~250 pages with notes on how to do curved flow in CFD. And so, I wanted to just share a few images of some pages with you all and see what your thoughts are on it.

There is everything in there relating to aerodynamics, CFD, turbulence, vehicle dynamics, glossaries, graphs, pictures, and more, all of which has been painstakingly hand-written with care, without a single leaflet, insert or anything. If I could not reproduce something by hand, I found a different way to visualise the phenomenon, and then I would draw that in the booklet.

I am unsure what to do with the booklet right now beyond just enjoying the immense amount of knowledge that is in there, knowing that I have absorbed almost all of it to better myself over these past years. I guess the first thing I need to do is buy another notebook eh?

So, without further ado, may I present: My CFD Bible !!

[Dipesh1995]

Very nice, thank you for sharing!

[arscottp]

Very nicely written.

One thing, in your 5th image with the Cp of the tire, Cp cannot be above 1. The paper you copied that from must be wrong.

[Vyssion]

Very nicely written.

One thing, in your 5th image with the Cp of the tire, Cp cannot be above 1. The paper you copied that from must be wrong.

Thanks for the compliment.

It actually isn't a mistake. For the stationary wheel, drawn in a solid red line as indicated, the Cp doesn't exceed unity you are quite right (unless my sketching skills were a little off that day anyways!).

However, in the case of the rotating wheel, which is the solid blue line, the reason that the Cp is able to exceed unity is due to the fact that the wheel is rotating. There is a paper by Fackrell that was done, where his attempt to explain this was that it was the "jetting" phenomenon, where the pressure coefficient increases above 1 at the contact patch. Essentially, this means that "work" is being done on the air as it is squeezed between the wheel and the moving ground, which gives rise to pressures that are greater than the total pressure in the working section. Following that high peak, there is a very strong negative pressure that exists after the line of contact, and although he never saw it experimentally, his theoretical prediction showed that it should exist. Another paper written by Mears in 2002 also did experimentation on an exposed rotating wheel and found good correlation to this in his results as well.