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3 | <meta http-equiv="CONTENT-TYPE" content="text/html; charset=windows-1252"><title>PALM |
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4 | chapter 3.0</title> <meta name="GENERATOR" content="StarOffice 7 (Win32)"> <meta name="AUTHOR" content="Marcus Oliver Letzel"> <meta name="CREATED" content="20040723;15213734"> <meta name="CHANGED" content="20041112;13170538"> <meta name="KEYWORDS" content="parallel LES model"> <style> |
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8 | </style></head> |
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9 | |
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10 | <body style="direction: ltr;" lang="en-US"><h2 style="font-style: normal; line-height: 100%;"><font size="4">3.0 |
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11 | Execution of model runs</font></h2> |
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12 | <p style="line-height: 100%;">Given that the model was |
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13 | installed by the user (look at <a href="chapter_5.0.html">chapter |
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14 | 5.0</a>) and that it is clear, which phenomenon is to be |
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15 | simulated, |
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16 | there is a whole set of questions which must be answered before |
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17 | executing |
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18 | the actual application run, e.g.: </p> |
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19 | <ul> <li> <p style="margin-bottom: 0cm; font-style: normal; line-height: 100%;">How |
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20 | large does the model domain have to be and what grid size does |
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21 | phenomenon to be simulated require? </p> </li> <li> |
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22 | <p style="margin-bottom: 0cm; font-style: normal; line-height: 100%;">How |
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23 | long is the time which should be simulated, i.e. which typical time |
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24 | scale does the phenomenon have? </p> </li> <li> <p style="margin-bottom: 0cm; font-style: normal; line-height: 100%;">Which |
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25 | boundary conditions and initial conditions are to be selected? </p> |
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26 | </li> <li> <p style="font-style: normal; line-height: 100%;">Which model |
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27 | output data are necessary at which points in time, in order to be able |
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28 | to analyze the phenomenon afterwards? </p> </li> |
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29 | </ul><p style="line-height: 100%;">The answers to |
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30 | these questions |
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31 | substantially determine the choice of values for the most important |
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32 | model parameters, with which the model run is steered. All possible |
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33 | parameters are described in chapters <a href="chapter_4.1.html">4.1</a>, |
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34 | <a href="chapter_4.2.html">4.2</a> |
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35 | and <a href="chapter_4.3.html">4.3</a>. |
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36 | The basic steering of the model with these parameters is explained in |
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37 | the introduction to <a href="chapter_4.0.html">chapter |
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38 | 4</a>. The user will rarely use all model parameters, since many |
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39 | are |
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40 | preset with consistent default values and therefore do not have to be |
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41 | changed by the user. Some of the most important parameters are not |
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42 | preset with default values and must be adjusted by the user in each |
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43 | case. Such a typical, minimum parameter set is described in <a href="chapter_4.4.html">chapter |
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44 | 4.4</a>. For the subsequent analysis of model runs, graphical |
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45 | visualization of model data is particularly important. <a href="chapter_4.5.html">Chapter |
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46 | 4.5</a> describes, how such outputs are produced with the model. </p> |
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47 | <p style="line-height: 100%;">The selected parameters and |
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48 | their values |
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49 | have to be supplied to the model as an input file. The |
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50 | structure of this file is described in the introduction to <a href="chapter_4.0.html">chapter |
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51 | 4</a>. The data, produced by the model, are located in a number |
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52 | of |
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53 | different output files. The model works with relative file names |
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54 | (i.e. without absolute path information). Thus all input and output |
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55 | files are |
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56 | expected and put in the directory, in which the actual model (the |
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57 | executable program created from the FORTRAN source code) is started |
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58 | (but also see next paragraph). |
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59 | All user-relevant input and output files are described in <a href="chapter_3.4.html">chapter |
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60 | 3.4</a>. </p> |
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61 | <p style="line-height: 100%;">The actual model (the |
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62 | executable |
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63 | program) is not started directly via the user, but with the help of |
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64 | the shell script <a href="http://www.muk.uni-hannover.de/institut/software/mrun_beschreibung.html">mrun</a>,which |
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65 | can be called by the user. This script takes over the entire pre- and |
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66 | postprocessing work, which is necessary for a model run. In addition |
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67 | to this, it generates e.g. automatically batch jobs for model runs on |
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68 | remote computers, provides for the appropriate file transfers of the |
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69 | input and output files to these computers, secures data on existing |
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70 | archives systems, starts if necessary restart jobs, and much more. |
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71 | <span style="font-weight: bold;">mrun</span> allows |
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72 | to specify |
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73 | individual path names for each simulation and |
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74 | for the different types of input/output files. The start of model runs |
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75 | with <b>mrun</b> is described in <a href="chapter_3.1.html">chapter |
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76 | 3.1</a>. </p> |
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77 | <p style="line-height: 100%;">The implementation of user |
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78 | code |
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79 | extensions in |
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80 | the model is made possible by a set of defined interfaces. You will |
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81 | find references to the programming of such extensions in <a href="chapter_3.5.html">chapter |
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82 | 3.5</a>. Frequently errors arise during the execution of the |
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83 | model |
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84 | after such changes, which can often be found only by interactive |
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85 | model steering and error tracing (debugging), which are described in |
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86 | <a href="chapter_3.6.html">chapter |
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87 | 3.6</a>. </p> |
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88 | <hr><p style="font-style: normal; line-height: 100%;"><br> |
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89 | <font color="#000080"><font color="#000080"><a href="chapter_2.0.html"><font color="#000080"><img src="left.gif" name="Grafik1" align="bottom" border="2" height="32" width="32"></font></a><a href="index.html"><font color="#000080"><img src="up.gif" name="Grafik2" align="bottom" border="2" height="32" width="32"></font></a><a href="chapter_3.1.html"><font color="#000080"><img src="right.gif" name="Grafik3" align="bottom" border="2" height="32" width="32"></font></a></font></font><br> |
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90 | </p><p style="font-style: normal; line-height: 100%;"><span style="font-style: italic;">Last change:</span> |
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91 | $Id: chapter_3.0.html 62 2007-03-13 02:52:40Z letzel $<br> |
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92 | </p></body></html> |
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