Changes between Version 3 and Version 4 of project/subproj/wpm2


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Timestamp:
Apr 11, 2017 8:55:35 AM (22 months ago)
Author:
maronga
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  • project/subproj/wpm2

    v3 v4  
    1616      {{{#!td style="border: none; width:50%"
    1717To evaluate the turbulent flow in an urban area, all relevant processes that affect the local environment need to be considered in a simulation, which cover a wide range of spatial scales, reaching from the small scale (e.g. effects of single tree or buildings) up to the regional (e.g. urban heat island) or even the synoptic scale. To resolve all those      spatial scales, the simulation has to run on a fine grid as well as for a large model   domain, however, today this is still hardly possible in terms of the available  computational resources. Here, the nesting technique offers an alternative, where the larger-scale processes are simulated on a coarse grid for a large model domain and the smaller-scale local processes are simulated on a fine grid only for the domain of  interest, so that all relevant processes can be considered.
    18 The main goal of this subproject  is to implement different nesting methods, which      allow to force <new model> with simulation data from larger-scale models, as well as toallow    a recursive <new model> self-nesting. The first approach enables <new model> to incoorporate external data from e.g. regional climate scenarios or even measured data,  while the second approach provides a kind of magnifying lens feature applied for a small limited area, e.g. to study effects of local buildings on the local environment.
     18The main goal of this subproject  is to implement different nesting methods, which allow to force PALM-4U with simulation data from larger-scale models, as well as to allow a recursive PALM-4U self-nesting. The first approach enables PALM-4U to incoorporate external data from e.g. regional climate scenarios or even measured data,  while the second approach provides a kind of magnifying lens feature applied for a small limited area, e.g. to study effects of local buildings on the local environment.
    1919         }}}
    2020      }}}
     
    2222\\
    2323== Work program ==
    24 ''WP-M2.1: <new model> nesting with larger scale models''
     24''WP-M2.1: PALM-4U nesting with larger scale models''
    2525
    26 Larger-scale models will provide synoptic or mesoscale data for <new model> as time-dependent mean wind-, temperature-, and humidity-profiles, which are further used to force the <new model> simulation by applying the large-scale forcing and nudging technique. Nesting will first be implemented for RANS-mode and realized in two different ways, first using time-dependent profiles at the lateral boundaries, and second,  adding larger-scale tendencies and subsidence to the horizontally averaged model state. Moreover, the second method has to be adjusted to be used for heterogeneous  surfaces. A data interface will be implemented for COSMO and ICON, in cooperation with work package D3. The large-scale forcing will be extensively tested and evaluated.
     26Larger-scale models will provide synoptic or mesoscale data for PALM-4U as time-dependent mean wind-, temperature-, and humidity-profiles, which are further used to force the PALM-4U simulation by applying the large-scale forcing and nudging technique. Nesting will first be implemented for RANS-mode and realized in two different ways, first using time-dependent profiles at the lateral boundaries, and second,  adding larger-scale tendencies and subsidence to the horizontally averaged model state. Moreover, the second method has to be adjusted to be used for heterogeneous  surfaces. A data interface will be implemented for COSMO and ICON, in cooperation with work package D3. The large-scale forcing will be extensively tested and evaluated.
    2727
    28 ''WP-M2.2: Recursive nesting – <new model>-ZOOM''
     28''WP-M2.2: Recursive nesting – PALM-4U-ZOOM''
    2929
    3030The recursive self-nesting will allow to run coarse- and fine-resolution simulation simulataneously, while the coarse-resolution simulation will provide full 2d-data at the lateral boundaries of the fine-resolution run. Interfaces between coarse and fine resolution runs will be implemented. The recursive nesting will be extensively tested and evaluated.
     
    3232''WP-M2.3: Nesting in LES mode''
    3333
    34 Nesting in LES-mode will provide a fully 3d-coupling between coarse- and fine-  resolution simulation, using the post-insertion method, where the 3d data is bi-laterally exchanged between the coarse- and the fine-resolution simulations. In case of nesting a turbulence resolving LES in a larger domain running in RANS-mode, where the   turbulence is fully parametrized, turbulence at lateral boundaries of the LES has to be generated. This will be done either by a turbulence recycling method or by a synthetic  turbulence generator. The fully 3d nesting in LES mode will be extensively tested and evaluated.
     34Nesting in LES-mode will provide a fully 3d-coupling between coarse- and fine-  resolution simulation, using the post-insertion method, where the 3d data is bi-laterally exchanged between the coarse- and the fine-resolution simulations. In case of nesting a turbulence resolving LES in a larger domain running in RANS-mode, where the turbulence is fully parametrized, turbulence at lateral boundaries of the LES has to be generated. This will be done either by a turbulence recycling method or by a synthetic turbulence generator. The fully 3d nesting in LES mode will be extensively tested and evaluated.
                                                                                                                                                                                                                                                                                                                                                                               
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