Changes between Version 8 and Version 9 of doc/app/examples/easytopo


Ignore:
Timestamp:
Sep 11, 2019 9:26:52 AM (6 years ago)
Author:
Giersch
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • doc/app/examples/easytopo

    v8 v9  
    11== Runs with easy topography ==
    22
    3 A simulation of a single surface-mounted cube in neutral channel flow with constant bulk velocity is presented. Cyclic lateral boundary conditions are used. The 3d-model is initialized with constant vertical profiles. Coriolis force is switched off ([../../inipar#omega omega] = 0.0). A constant volume flow (i.e. constant bulk velocity) is maintained ([../../inipar#conserve_volume_flow conserve_volume_flow] = .T.). The flow is explicitly set neutral ([../../inipar#neutral neutral] = .T.), i.e. the prognostic equation for temperature and other buoyancy terms must not be calculated, which saves computation time. To set the channel flow boundary condition, the horizontal velocity components at the domain top are kept zero ([../../inipar#bc_uv_t bc_uv_t] = 'dirichlet_0').
     3The {{{first example}}} on this page shows a simulation of a single surface-mounted cube in neutral channel flow with constant bulk velocity. A constant bulk velocity means that the volume flow at the inflow boundary equals at each time step the volume flow at the outflow. For volume flow conservation, the initial profiles are used. Besides, cyclic lateral boundary conditions are used. The 3d-model is initialized with constant vertical profiles. Coriolis force is switched off ([../../inipar#omega omega] = 0.0). A constant volume flow (i.e. constant bulk velocity) is maintained ([../../inipar#conserve_volume_flow conserve_volume_flow] = .T.). The flow is explicitly set neutral ([../../inipar#neutral neutral] = .T.), i.e. the prognostic equation for temperature and other buoyancy terms must not be calculated, which saves computation time. To set the channel flow boundary condition, the horizontal velocity components at the domain top are kept zero ([../../inipar#bc_uv_t bc_uv_t] = 'dirichlet_0').
    44The cube is constructed using the rasterized topography mode ([../../inipar#topography topography] = 'read_from_file') with the default [../../inipar#topography_grid_convention topography_grid_convention] = 'cell_center'. You can find the input files for the simulation in the [source:palm/trunk/TESTS/cases/topo_from_ASCII_file/INPUT/ trunk].
    55
    6 In a second example, the cube is constructed using the single building topography mode ([../../inipar#topography topography] = 'single_building') with the default [../../inipar#topography_grid_convention topography_grid_convention] = 'cell_edge'. The results of the two examples should be the same. The parameter file using the single building topography mode is attached to this page.
     6In a {{{second example}}}, the cube is constructed using the single building topography mode ([../../inipar#topography topography] = 'single_building') with the default [../../inipar#topography_grid_convention topography_grid_convention] = 'cell_edge'. The results of the two examples should be the same. The parameter file using the single building topography mode is attached to this page.
     7
     8A {{{third simulation example}}} using a idealized single street canyon under neutral conditions can be found [source:palm/trunk/TESTS/cases/street_canyon here]. A constant bulk velocity is used as in the first example, which means that the volume flow at the inflow boundary equals at each time step the volume flow at the outflow. For volume flow conservation, the initial profiles are used. The canyon is 40 m high and wide (x-direction), infinitely long in y-direction, and centered in the model domain.
     9
     10Finally, a {{{fourth example}}} using a more complex topography than just a single building or street canyon can be found under the [source:palm/trunk/EXAMPLES/mountain EXAMPLES] folder in the trunk. This example shows the flow around a single 3d idealized mountain. The mountain shape is Gaussian. The inversion height lies below the mountain top so that a part of the topography resides in stable stratification. Cyclic lateral boundary conditions are used. The 3d-model is initialized with the solution of the 1d-model. In addition, Rayleigh damping is switched on. The topography file in ASCII format is created with aid of a 2d Gauss function.