How to start a 2D CFD code?

entropies · August 2, 2011, 12:17

Hi everybody,

I just want to start from scratch of building a 2D/2D-axis NS program which is used in compressible flow. I prefer to use FORTRAN as the developing language. Is there any good reference to start with?

Simple will be great! At the moment, I think structured grid is enough for my application.

Thanks a lot.
Qi

cfdnewbie · August 2, 2011, 12:29

If you want to write your own Finite Volume code, there's no better book than Blazcek:
http://books.google.com/books?id=IKu...page&q&f=false

That explains how to write a FV code from scratch, if you understand that, you'll be well on your way...

entropies · August 2, 2011, 12:38

Quote:

Originally Posted by cfdnewbie

If you want to write your own Finite Volume code, there's no better book than Blazcek:
http://books.google.com/books?id=IKu...page&q&f=false

That explains how to write a FV code from scratch, if you understand that, you'll be well on your way...

I just got Blazek's book from library last week. I found out there is already some 2d programs attached in the CD-ROM.

Two quick questions:
1. Is it a compressible NS code?
2. Is it non-dimensional or dimensional?

Thank you!
Qi

cfdnewbie · August 2, 2011, 12:44

Sorry, I have never actually looked at the CD, so I do not know....but maybe there's a readme on the CD, or you might look at the code and find comments in it?

VincentD · August 2, 2011, 14:17

Just look at the continuity equation, if it's \nabla \bf{U} then you know it's incompressible. If they are taking time derivatives of \rho it's compressible.

Docfreezzzz · August 2, 2011, 15:05

You'll find that most CFD codes are written in a non-dimensional way for conditioning reasons. Very likely the only place you'll run into dimensions is when dealing with chemistry components and even then only in the fluid property evaluations. There are some very specific mathematical reasons for this.

cfdnewbie · August 2, 2011, 15:19

Quote:

Originally Posted by VincentD

Just look at the continuity equation, if it's \nabla \bf{U} then you know it's incompressible. If they are taking time derivatives of \rho it's compressible.

Just be careful with this, it is not uncommon to name the conservative state vector \bf{U} as well, which then turns out to be (rho, rhou, rhov...)

August 2, 2011, 12:17	How to start a 2D CFD code?	#1
entropies New Member Qi Guan Join Date: Aug 2011 Posts: 27 Rep Power: 14	Hi everybody, I just want to start from scratch of building a 2D/2D-axis NS program which is used in compressible flow. I prefer to use FORTRAN as the developing language. Is there any good reference to start with? Simple will be great! At the moment, I think structured grid is enough for my application. Thanks a lot. Qi

August 2, 2011, 12:29		#2
cfdnewbie Senior Member cfdnewbie Join Date: Mar 2010 Posts: 557 Rep Power: 20	If you want to write your own Finite Volume code, there's no better book than Blazcek: http://books.google.com/books?id=IKu...page&q&f=false That explains how to write a FV code from scratch, if you understand that, you'll be well on your way... entropies likes this.

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August 2, 2011, 12:44		#4
cfdnewbie Senior Member cfdnewbie Join Date: Mar 2010 Posts: 557 Rep Power: 20	Sorry, I have never actually looked at the CD, so I do not know....but maybe there's a readme on the CD, or you might look at the code and find comments in it?

August 2, 2011, 14:17		#5
VincentD New Member Vincent Join Date: Jul 2011 Posts: 29 Rep Power: 14	Just look at the continuity equation, if it's \nabla \bf{U} then you know it's incompressible. If they are taking time derivatives of \rho it's compressible.

August 2, 2011, 15:05		#6
Docfreezzzz Member Join Date: Jul 2011 Location: US Posts: 39 Rep Power: 14	You'll find that most CFD codes are written in a non-dimensional way for conditioning reasons. Very likely the only place you'll run into dimensions is when dealing with chemistry components and even then only in the fluid property evaluations. There are some very specific mathematical reasons for this.