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-   -   Normalization or non-dimensionalization. Why? (https://www.cfd-online.com/Forums/main/14265-normalization-non-dimensionalization-why.html)

jinwon park October 17, 2007 09:23

Normalization or non-dimensionalization. Why?
 
Could I ask you about the term, 'normalization or non-dimensionalization' in solving compressible flow? I am currently solving compressible two-dimensional flow based on Euler equations. I am understanding how to normalize density and pressure but I don't know how to do time and length. Could you let me know how to normalize the time and length in Euler computations.

For example, density in left=1630kg/m^3 <--> density in right=1000kg/m^3. when normalizing 1.63 and 1.0

Pressure in left=1e9Pa <--> Pressure in right=1e5Pa When normalizing 1.0 and 0.0001


ag October 17, 2007 12:04

Re: Normalization or non-dimensionalization. Why?
 
One standard method of nondimensionalization for the compressible Euler/NS equations is to define a reference density rho_ref, reference velocity, typically taken as the speed of sound at some reference temperature T_ref and reference density rho_ref, and a reference length L_ref which can be the grid dimension or it could be related to some physical dimension of the problem. Then pressure is non-dimensionalized as p_non = p/(rho_ref*a_ref**2), density is non-dimensionalized as rho_non = rho/rho_ref, time is non-dimensionalized as t_non = t*a_ref/L_ref, etc.

jinwon park October 17, 2007 12:06

Re: Normalization or non-dimensionalization. Why?
 
Can I ask you a reference on this?

ag October 17, 2007 13:29

Re: Normalization or non-dimensionalization. Why?
 
Just about any basic textbook that deals with density-based schemes will have this. See Hoffman & Chiang, "Computational Fluid Dynamics for Engineers", for one.

jinwon park October 17, 2007 13:31

Re: Normalization or non-dimensionalization. Why?
 
I really appreciate your kind help. Thanks.

billpeace October 18, 2007 23:40

Re: Normalization or non-dimensionalization. Why?
 
Can i find the code for book "Computational Fluid Dynamics for Engineers" free?



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