Possible Deprecation of turbulentInlet Boundary Condition

Hi,

turbulentInlet boundary condition generates fluctuating velocity fields by superimposing (pseudo-)random number sets (scaled by a given turbulence intensity) onto a reference (mean) velocity field.

https://www.openfoam.com/documentation/cpp-guide/html/classFoam_1_1turbulentInletFvPatchField.html

Although this approach was proposed in the literature as the first turbulence inflow method, numerous studies quantified its ineffectiveness (refs can be provided if need be). Unfortunately, turbulence is fully deterministic and involving various spatial/temporal coherent structures, yet is random in a sense that its stochastic development cannot be predicted, again due to its acute sensitivity to initial/boundary conditions.

For example, in detail, for turbulentInlet the energy of generated time-series is equally distributed over the whole wavenumber range, that means the spectrum is approximately a horizontal line. Therefore, due to a lack of energy in the low wave number range, the pseudo turbulence is immediately damped to zero when enters into a CFD domain, and the result is virtually identical with a laminar inflow.

For these reasons, I kindly suggest a discussion as to this module's deprecation since customers/developers/users could be misled by its name and offerings.