Changeset 206 for palm/trunk/DOC/app/chapter_3.9.html

Timestamp:

Oct 13, 2008 2:59:11 PM (16 years ago)

Author:

raasch

Message:

ocean-atmosphere coupling realized with MPI-1, adjustments in mrun, mbuild, subjob for lcxt4

File:

• palm/trunk/DOC/app/chapter_3.9.html (modified) (2 diffs)

palm/trunk/DOC/app/chapter_3.9.html

@@ -28 +28 @@
 PALM includes a so-called turbulence recycling method which allows a
 turbulent inflow with non-cyclic horizontal boundary conditions. The
-method follows the one described by Lund et al. (1998, J. Comp. Phys., <span style="font-weight: bold;">140</span>, 233-258), modified by Kataoka and Mizuno (2002, Wind and Structures, <span style="font-weight: bold;">5</span>, 379-392). The method is switched on by setting the initial parameter <a href="chapter_4.1.html#turbulent_inflow">turbulent_inflow</a> = <span style="font-style: italic;">.TRUE.</span>.</p><p style="line-height: 100%;">The turbulent signal A'(y,z) to be imposed at the left inflow boundary is taken from the simulation at a fixed distance x<sub>r</sub> from the inflow (given by parameter <a href="chapter_4.1.html#recycling_width">recycling_width</a>): A'(y,z) = A(x<sub>r</sub>,y,z) - <span style="font-weight: bold;">A(z)</span>, where <span style="font-weight: bold;">A(z)</span>
+method follows the one described by Lund et al. (1998, J. Comp. Phys., <span style="font-weight: bold;">140</span>, 233-258), modified by Kataoka and Mizuno (2002, Wind and Structures, <span style="font-weight: bold;">5</span>, 379-392). The method is switched on by setting the initial parameter <a href="chapter_4.1.html#turbulent_inflow">turbulent_inflow</a> = <span style="font-style: italic;">.TRUE.</span>.</p><p style="line-height: 100%;">The turbulent signal A'(y,z) to be imposed at the left inflow boundary is taken from the same simulation at a fixed distance x<sub>r</sub> from the inflow (given by parameter <a href="chapter_4.1.html#recycling_width">recycling_width</a>): A'(y,z) = A(x<sub>r</sub>,y,z) - <span style="font-weight: bold;">A(z)</span>, where <span style="font-weight: bold;">A(z)</span>
 is the horizontal average between the inflow boundary and the recycling
 plane. The turbulent quantity A'(y,z) is then added to a mean inflow
@@ -39 +39 @@
 horizontal average from this precursor run is used as the mean inflow
 profile for the main run, the wall-normal velocity component must point
-into the domain at every grid point and its magnitude should be large enough in order to guarantee an inflow even if a turbulence signal is added.</li><li>Since the main run requires &nbsp;...</li><li>The
+into the domain at every grid point and its magnitude should be large
+enough in order to guarantee an inflow even if a turbulence signal is
+added.<br></li><li>The
+main run requires&nbsp;from the precursor run&nbsp;the mean profiles to
+be used at the inflow. For this, the horizontally and temporally
+averaged mean profiles as provided with the standard PALM output are
+used. The user has to set parameters <a href="chapter_4.2.html#dt_data_output_pr">dt_data_output_pr</a>, <a href="chapter_4.2.html#averaging_interval">averaging_interval</a>,
+etc. for the precursor run appropriately, so that an output is done at
+the end of the precursor run. The profile information is then contained
+in the restart (binary) file created at the end of the precursor run
+and can be used by the main run. <span style="font-weight: bold;">It is very important that the mean profiles at the end of the precursor run are in a stationary or quasi-stationary state</span>, because otherwise it may not be justified to use them as constant profiles at the inflow. <span style="font-weight: bold;">Also, turbulence at the end of the precursor run should be fully developed. </span>Otherwise, the main run would need an additional spinup-time at the beginning to get the turbulence to its final stage.<br></li><li>The
 main run has to read the binary data from the precursor run .... &nbsp;
 &nbsp; set bc_lr = 'dirichlet/radiation' ... &nbsp;