Changes between Version 9 and Version 10 of doc/tec/bugs


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Timestamp:
Jun 13, 2016 2:39:49 PM (9 years ago)
Author:
suehring
Comment:

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  • TabularUnified doc/tec/bugs

    v9 v10  
    33||='''Date'''  =||='''Reported by'''  =||='''Description'''  =||
    44|----------------------
    5 ||09/05/16 || MS || For very complex topography, e.g. very narrow street canyons or corners that are resolved by only one or two grid points, the use of psolver = 'multigrid' and masking_method = .F. can lead to a blow up of wind velocity. ||
     5||09/05/16 || MS || For very complex topography, e.g. very narrow street canyons or corners that are resolved by only one or two grid points, the use of psolver = 'multigrid_noopt' and masking_method = .F. can lead to a blow up of wind velocity. Please see remarks below. ||
    66|----------------------
    77||09/05/16 || MS || In case of topography = .T., different processor topologies do not yield identical results. ||
    88|----------------------
    9 ||21/03/14 || MS || Computation of spectra is currently not possible with '''[../../app/inipar#fft_method fft_method]''' = 'fftw'. ||
    10 |----------------------
    119||18/04/12 || MS || The use of the cache-optimized and the vector-optimized Palm versions do not yield identical results. ||
    1210
     11\\\\
     12'''Remarks with respect to usage of psolver = 'multigrid_noopt'''' \\
    1313
     14In case of very complex topography, including narrow street canyons or complex shapes resolved by only a few grid points, the use of psolver = 'multigrid_noopt' in combination with masking_method = .F. can lead to a blow up of wind velocity. So far, this never happened if masking_method = .T. or psolver = 'multigrid' (where topography is always masked).
     15A possible workaround to prevent such velocity blow-up is to preprocess the topography by filling holes and removing complex shapes on the small scale before running the LES. (This approach should have no significant effect on the flow field, as in LES the flow in such regions is poorly resolved and do not yield to reliable physical information.)
     16The reason for this velocity blow-up is unclear so far.