Parameters of dynamic model in LES

[chenyx]

Hello,

In code_saturne 7.0.4, I noted that the parameter of dynamic model in LES is different with other sovler like charLES. More specifically, the equation
delta = xfil *(xa*volume(iel))**xb
where xfil defaults to 2.0, xa to 1.0, xb to 1/3, which is different with other sovler that use xfil to be 1.0
Second, the filtered delta equation :
deltaf = xfil2*delta
where xfil2 = 1.5 ,which is also different with other sovler that use xfil2 to be 2.0
Therefore, why these parameters are set like that which is different with the LES textbook and other sovler.

Best regards,
Chen yuxuan