Dear All,

I am a university final year student. I am now participating in a project of implementing a paper on Computational Fluid Dynamics for compressible fluid. However, I got a problem of understanding some of the terms in the equations provided in the paper.

I have put a part of the paper on the web. The address is:

http://ihome.cuhk.edu.hk/~s976337/fluid/gethelp.html

In the equations, there are terms with bars on top. And the paper describe these terms as "Base state variables, denoted by overbars, are time-invariant functions of z, the vertical coordinate." But I cannot understand what is the meaning of it even after discussing with others.

Could any one interested in CFD gives me a help? I will be glad if this problem can be solved.

Thanks a lot! Billy Leung

(1). I think, it is trying to say that, the variable with a bar on the top of it, is not a function of time (in the transient equations). It is (or those are) a function of z.