Does CFX use modified pressure in the code? If yes, how can I change it?

In CFX-Pre, Solver and Post the Static Pressure or Total Pressure always includes the turbulence contribution term 2/3*rho*k by default for k-epsilon/k-omega based turbulence models; this is called the modified pressure, p':

Static Pressure: p'=p+2/3*rho*k
Total Pressure: ptotal = p+2/3*rho*k + 1/2 * rho*u^2

To be more specific, by default, in CFX-Pre, when the user sets the boundary condition to either an outlet or opening type of boundary where the pressure value is required, the value expected is the modified pressure. In the CFX-Solver the modified pressure is used. In CFX-Post, the pressure plotted has the turbulence term included, but it will be subtracted before calculating other variables that depend on the pressure, such as fluid properties.

There is an expert parameter called "pressure value option" which the user can set to change the pressure definition. When set, the CFX-Solver has the following behaviour:

pressure value option = 2 (default)
p`=p+2/3*rho*k where rho =(p`ab-2/3*rho*k)/RT and p`ab is the absolute modified pressure

pressure value option = 1
p`=p+2/3*rho*k where rho =(p`ab)/RT

pressure value option = 3
p`= p

In CFX-Pre the behaviour is as follows (for boundary condition definitions):

pressure value option = 2 (default)
The user should enter the modified pressure.

pressure value option = 1
The user should enter the true static pressure, and the solver will add 2/3*rho*k as the boundary condition value.

pressure value option = 3
The user should enter is the true static pressure, and it will be used for pressure boundary condition value in solver.

CFX-Post simply plots the pressure output from the CFX-Solver.

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