ENH: turbulentDigitalFilter: Synthetic fluctuations of scalars
Aim
To enable synthetic fluctuations of scalars (e.g. temperature or contaminant concentrations) for the turbulentDigitalFilterInlet
boundary condition.
Previous status
 Produces only vectorbased fluctuations
 Input entries of mean and Reynolds stresses are limited to be either constant or simple wallnormal profiles
 Contains unresolved bugs:
 #1725
 #2262 (closed)
 #2267 (closed) (Parallelisation)
 #2329 (closed) (FSM is inoperative)
 Domain rotations/translations are not possible
 Parallelisation and scaling are problematic
 Restart is problematic
 Mapping fluctuations onto an inlet patch is problematic and limited to only the nearestcell option
 Adjustable timestep simulations are not possible
Improvements
 Produces vector or scalarbased fluctuations
 New inputentry types:
 Mean and Reynolds stresses have become
PatchFunction1
type  Timevariant input for mean and Reynolds stresses is possible
 Number of input entries have been simplified by reducing the number from 16 to 8, most of which are default valued.
 Mean and Reynolds stresses have become
 Resolves the reported bugs
 Domain rotations/translations are improved
 Users can set a local coordinate system
 Parallelisation and scaling are improved
 Restart is improved
 Mapping fluctuations onto an inlet patch is improved and generalised
 Users can select an AMI mapping method for the mapping operation
 Adjustable timestep simulations are possible for the FSM option
 Removes Taylor's frozen turbulence assumption for the streamwise integral scale calculations
Resolved bugs
#1725 #2262 (closed) #2267 (closed) #2329 (closed)
Methodology
Results
DFM  only vector
DFM  only scalar
DFM  vector+scalar
FSM  only vector
FSM  only scalar
FSM  vector+scalar
Metadata
EP#1730

Clean compilation (incl. submodules): 
linux64ClangDPInt32Opt
(clang11) 
linux64GccDPInt32Opt

linux64GccSPDPInt64Debug


Alltest: No new error
Future work  Constraints
 Test scope should be extended further for:
 Integral length scales
 Domain rotations and/or translations
 Multiphaseflow cases
 Dynamicmesh cases
 Overset meshes
 Mesh (un)refinements
 Collateddata format
 Hybrid and single precisions

transformPoints
utility has no effect onboundaryData
input, which can slow down case preparations for input sets which need to be rotated/translated  Scalarbased condition
 No constraints on nonpositive output
 Scarce and ambiguous academic resources
 No crosscorrelations
 Not easy to produce/find benchmark data from theory or measurements
 Usefulness is not clarified by academia
 DFM
 Incomplete parallelisation of the threedimensional separable convolution due to the lack of no opensource algorithms
The use ofredistributePar decompose
utility is not supported.
Edited by Kutalmış Berçin