Changes between Version 23 and Version 24 of doc/app/examples/turbinf

Timestamp:

Dec 5, 2019 9:47:14 AM (6 years ago)

Author:

oliver.maas

Comment:

--

doc/app/examples/turbinf

@@ -33 +33 @@
     Set [../../inipar#turbulent_inflow turbulent_inflow] = .T. .
 
-    Define the position of the recycling plane via [../../inipar#recycling_width recycling_width]. The distance between the inflow and the recycling plane should be large enough to allow for a sufficient advancement of the turbulent eddies (should be somehow correlated with the eddy turnover time). Otherwise, almost the same eddies will be recycled again and again, which will distort the turbulence statistics. Typically, the recycling width will be about the same size as the domain size of the precursor run. It is, however, recommended that both sizes do not exactly match to prevent the development of fixed-sized structures.
+    Define the position of the recycling plane via [../../inipar#recycling_width recycling_width]. The distance between the inflow and the recycling plane should be large enough to cover at least one lifetime (Lagrangian time scale) of the largest eddies. Otherwise, the turbulent structures do not have enough time to change before they are recycled, resulting in regular patterns in the flow field and distorted statistics. For estimating the Lagrangian time scale refer to [#anfossi2006 Anfossi et al. (2006)]. Typically, the recycling width will be about the same size as the domain size of the precursor run. It is, however, recommended that both sizes do not exactly match to prevent the development of fixed-sized structures.
 
     A damping layer for the turbulence signal can be set at top of the domain via [../../inipar#inflow_damping_height inflow_damping_height] and [../../inipar#inflow_damping_width inflow_damping_width]. Inside the damping layer the turbulence signal is linearly damped to 0%. For [../../inipar#inflow_damping_height inflow_damping_height] the boundary layer height from the precursor run should be used.
 
-    The recycled turbulence, which is mapped from the recycling plane to the inflow boundary, can be shifted in y direction. This y-shift reduces persistent streaks that may occur within the recycling domain. To use the y-shift [../../inipar#recycling_yshift recycling_yshift] = .T. needs to be set. The distance of the y-shift is INT([../../d3par#npey npey] / 2), which is in most cases the best distance for effectively reducing streaks in the recycling domain. It might be also a good idea to reduce persistent streaks directly in the precursor run by using the parameter [../../inipar#y_shift y_shift]. 
+    The recycled turbulence, which is mapped from the recycling plane to the inflow boundary, can be shifted in y direction. This y-shift reduces persistent streaks that may occur within the recycling domain. To use the y-shift set [../../initialization_parameters#y_shift y_shift] to a non-zero value. The distance of the y-shift is given in number of processors (PE) and should be roughly equal to the boundary layer height. For an effective reduction of streaks it is important that the flow passes the domain many times until it is shifted to its initial y-position. The number of flowthroughs is given by the least common multiple of y_shift and [../../initialization_parameters#npey npey] divided by y_shift. For further details refer to Munters (2016; ​http://www.dx.doi.org/10.1063/1.4941912).
 
   * When starting the main run, [wiki:doc/app/palmrun palmrun] must be told to provide the binary data of the restart run which is done by adding 'rec' to the activation-string list of the palmrun command (option {{{-a}}}, see job control with [wiki:doc/app/palmrun palmrun]). 
@@ -50 +50 @@
 
 * '''[=#kataoka2002 Kataoka, H.] and M. Mizuno, 2002:''' Numerical flow computation around aeroelastic 3D square cylinder using inflow turbulence. ''Wind Struct.'', '''5''', 379-392.
+
+* '''[=#anfossi2006 Anfossi, D.], U. Rizza, C. Mangia, G.A. Degrazia and E. Pereira Marques Filho, 2006:''' Estimation of the ratio between the Lagrangian and Eulerian time scales in an atmospheric boundary layer generated by large eddy simulation. ''Atmospheric Environment'', '''40''', 326-337.