[poly_tec]

careful bro. I got punished by an admin yesterday for pointing out the same cringeworthy thing…

[Dr Youssef Hafez]

If there are 1000 CFD codes let them be 1000 and one; what is the problem?

[poly_tec]

no problem, just commercial value: 0.0

[Dr Youssef Hafez]

An advantage of my code is the treatment of the pressure variable.
The pressure has a mathematical, not a thermodynamic meaning. According to RANS the pressure is not uniquely defined as any pressure function could satisfy the RANS up to an additive constant so a family of parallel pressure surface fields would satisfy the RANS mathematically speaking. However, knowing one pressure value would tie the solution. In fact, from a CFD or mathematical prospective the pressure is just a constraint to enforce the incompressibility constraint or the velocity divergence free condition (Div. V =0).

One possible treatment of the pressure is through expresssing the pressure using the penalty approach as:
- p/k = (Div. V) ; or p = - K (Div. V)
where K is a penalty parameter that is supposed to have a very large values (ideally infinite value) so at such very large values Div. (V) =0.0 .
A better formulation is the iterative penalty method which I used in my codes which is:
p (at iteration i+1) = p (at iteration i) - K (Div. V)
In the iterative penalty method smaller values could be taken for k, e.g. k maybe 100 to avoid using very large numbers.
When using the pressure penalty approach, no need to solve the continuity equation on the global scale and in fact the pressure is substituted for using the above mentioned equation in RANS and the pressure is no longer an unknown which reduces the number of unknowns to only the velocities. This is a big computational advantage saving significant memory storage. However, the pressure can be recovered by solving on the element or cell scale using the penalty equation and the obtained values are true within an additive constant. Knowing one value of pressure, the pressure values obtained could be easily scaled.