/[MITgcm]/manual/s_examples/rotating_tank/tank.tex
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Revision 1.11 - (hide annotations) (download) (as text)
Sat Oct 16 03:40:15 2004 UTC (20 years, 9 months ago) by edhill
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 o add HTML comments as a step towards "URL permanence" which will help
   solve:
   - stale links from the CMI web site
   - rotten indexing by bonniefy.pl
 o also cleanup a merge-mangle in diagnostics.tex

1 edhill 1.11 % $Header: /u/gcmpack/manual/part3/case_studies/rotating_tank/tank.tex,v 1.10 2004/10/13 18:52:17 afe Exp $
2 afe 1.1 % $Name: $
3    
4     \bodytext{bgcolor="#FFFFFFFF"}
5    
6     %\begin{center}
7 afe 1.3 %{\Large \bf Using MITgcm to Simulate a Rotating Tank in Cylindrical
8     %Coordinates}
9 afe 1.1 %
10     %\vspace*{4mm}
11     %
12     %\vspace*{3mm}
13 afe 1.3 %{\large May 2001}
14 afe 1.1 %\end{center}
15    
16 afe 1.3 \section{A Rotating Tank in Cylindrical Coordinates}
17     \label{sect:eg-tank}
18 afe 1.2 \label{www:tutorials}
19 edhill 1.11 \begin{rawhtml}
20     <!-- CMIREDIR:eg-tank: -->
21     \end{rawhtml}
22 afe 1.2
23 afe 1.4 This section illustrates an example of MITgcm simulating a laboratory
24 afe 1.10 experiment on much smaller scales than those commonly considered in
25     geophysical
26 afe 1.4 fluid dynamics.
27    
28     \subsection{Overview}
29     \label{www:tutorials}
30    
31    
32 afe 1.10 This example configuration demonstrates using the MITgcm to simulate
33     a laboratory demonstration using a rotating tank of water with an ice
34 afe 1.4 bucket in the center. The simulation is configured for a laboratory
35     scale on a
36     $3^{\circ}$ $\times$ 20cm
37     cyclindrical grid with twenty-nine vertical
38     levels.
39     \\
40 afe 1.10 example illustration from GFD lab here
41     \\
42 afe 1.4
43    
44 afe 1.2
45 afe 1.3
46    
47     \subsection{Equations Solved}
48     \label{www:tutorials}
49 afe 1.1
50 afe 1.3
51     \subsection{Discrete Numerical Configuration}
52     \label{www:tutorials}
53    
54     The domain is discretised with
55 afe 1.10 a uniform cylindrical grid spacing in the horizontal set to
56     $\Delta a=1$~cm and $\Delta \phi=3^{\circ}$, so
57     that there are 120 grid cells in the azimuthal direction and thirty-one grid cells in the radial. Vertically the
58     model is configured with twenty-nine layers of uniform 0.5cm thickness.
59     \\
60     something about heat flux
61 afe 1.2
62 afe 1.3 \subsection{Code Configuration}
63 afe 1.1 \label{www:tutorials}
64 afe 1.3 \label{SEC:eg-baro-code_config}
65 afe 1.1
66 afe 1.5 The model configuration for this experiment resides under the
67     directory {\it verification/rotatingi\_tank/}. The experiment files
68 afe 1.1 \begin{itemize}
69     \item {\it input/data}
70     \item {\it input/data.pkg}
71     \item {\it input/eedata},
72 afe 1.5 \item {\it input/bathyPol.bin},
73     \item {\it input/thetaPol.bin},
74 afe 1.1 \item {\it code/CPP\_EEOPTIONS.h}
75     \item {\it code/CPP\_OPTIONS.h},
76 afe 1.5 \item {\it code/SIZE.h}.
77 afe 1.1 \end{itemize}
78 afe 1.5
79 afe 1.3 contain the code customizations and parameter settings for this
80 afe 1.1 experiments. Below we describe the customizations
81     to these files associated with this experiment.
82    
83     \subsubsection{File {\it input/data}}
84     \label{www:tutorials}
85    
86     This file, reproduced completely below, specifies the main parameters
87     for the experiment. The parameters that are significant for this configuration
88     are
89    
90     \begin{itemize}
91    
92 afe 1.10 \item Line 10, \begin{verbatim} viscAh=5.0E-6, \end{verbatim} this line sets
93     the Laplacian friction coefficient to $6 \times 10^{-6} m^2s^{-1}$,
94     which is ususally
95 afe 1.6 low because of the small scale, presumably.... qqq
96    
97 afe 1.10 \item Line 19, \begin{verbatim}f0=0.5 , \end{verbatim} this line sets the
98     coriolis term, and represents a tank spinning at 2/s
99     \item Line 20, \begin{verbatim} beta=1.E-11, \end{verbatim} this line sets
100 afe 1.3 $\beta$ (the gradient of the coriolis parameter, $f$) to $10^{-11} s^{-1}m^{-1}$
101    
102 afe 1.10 \item Lines 27 and 28
103 afe 1.3 \begin{verbatim}
104 afe 1.6 rigidLid=.TRUE.,
105     implicitFreeSurface=.FALSE.,
106 afe 1.3 \end{verbatim}
107 afe 1.6
108 afe 1.10 qqq these lines do the opposite of the following:
109 afe 1.6 suppress the rigid lid formulation of the surface
110 afe 1.3 pressure inverter and activate the implicit free surface form
111     of the pressure inverter.
112 afe 1.1
113 afe 1.10 \item Line 44,
114 afe 1.1 \begin{verbatim}
115 afe 1.10 nIter=0,
116 afe 1.1 \end{verbatim}
117 afe 1.3 this line indicates that the experiment should start from $t=0$
118     and implicitly suppresses searching for checkpoint files associated
119     with restarting an numerical integration from a previously saved state.
120 afe 1.2
121 afe 1.10 \item Line 47,
122 afe 1.1 \begin{verbatim}
123 afe 1.6 deltaT=0.1,
124 afe 1.1 \end{verbatim}
125 afe 1.6 This line sets the integration timestep to $0.1s$. This is an unsually
126     small value among the examples due to the small physical scale of the
127     experiment.
128 afe 1.1
129 afe 1.10 \item Line 58,
130 afe 1.1 \begin{verbatim}
131 afe 1.6 usingCylindricalGrid=.TRUE.,
132 afe 1.1 \end{verbatim}
133 afe 1.3 This line requests that the simulation be performed in a
134 afe 1.7 cylindrical coordinate system.
135 afe 1.1
136 afe 1.10 \item Line 60,
137 afe 1.1 \begin{verbatim}
138 afe 1.7 dXspacing=3,
139 afe 1.1 \end{verbatim}
140 afe 1.10 This line sets the azimuthal grid spacing between each $x$-coordinate line
141 afe 1.3 in the discrete grid. The syntax indicates that the discrete grid
142 afe 1.7 should be comprise of $120$ grid lines each separated by $3^{\circ}$.
143    
144    
145 afe 1.1
146 afe 1.10 \item Line 61,
147 afe 1.1 \begin{verbatim}
148 afe 1.7 dYspacing=0.01,
149 afe 1.1 \end{verbatim}
150 afe 1.10 This line sets the radial cylindrical grid spacing between each $a$-coordinate line
151 afe 1.7 in the discrete grid to $1cm$.
152 afe 1.1
153 afe 1.10 \item Line 62,
154 afe 1.1 \begin{verbatim}
155 afe 1.7 delZ=29*0.005,
156 afe 1.2 \end{verbatim}
157 afe 1.3 This line sets the vertical grid spacing between each z-coordinate line
158     in the discrete grid to $5000m$ ($5$~km).
159 afe 1.1
160 afe 1.10 \item Line 68,
161 afe 1.1 \begin{verbatim}
162 afe 1.7 bathyFile='bathyPol.bin',
163 afe 1.1 \end{verbatim}
164     This line specifies the name of the file from which the domain
165 afe 1.7 ``bathymetry'' (tank depth) is read. This file is a two-dimensional
166 afe 1.10 ($a,\phi$) map of
167 afe 1.1 depths. This file is assumed to contain 64-bit binary numbers
168 afe 1.10 giving the depth of the model at each grid cell, ordered with the $\phi$
169 afe 1.1 coordinate varying fastest. The points are ordered from low coordinate
170 afe 1.7 to high coordinate for both axes. The units and orientation of the
171 afe 1.1 depths in this file are the same as used in the MITgcm code. In this
172 afe 1.7 experiment, a depth of $0m$ indicates an area outside of the tank
173     and a depth
174     f $-0.145m$ indicates the tank itself.
175 afe 1.1
176 afe 1.10 \item Line 67,
177 afe 1.7 \begin{verbatim}
178     hydrogThetaFile='thetaPol.bin',
179     \end{verbatim}
180     This line specifies the name of the file from which the initial values
181 afe 1.10 of temperature
182 afe 1.7 are read. This file is a three-dimensional
183     ($x,y,z$) map and is enumerated and formatted in the same manner as the
184     bathymetry file.
185 afe 1.1
186 afe 1.7 \item Line qqq
187 afe 1.1 \begin{verbatim}
188 afe 1.7 tCyl = 0
189 afe 1.1 \end{verbatim}
190 afe 1.7 This line specifies the temperature in degrees Celsius of the interior
191     wall of the tank -- usually a bucket of ice water.
192    
193 afe 1.1
194     \end{itemize}
195    
196     \noindent other lines in the file {\it input/data} are standard values
197     that are described in the MITgcm Getting Started and MITgcm Parameters
198     notes.
199    
200 afe 1.2 \begin{small}
201 afe 1.5 \input{part3/case_studies/rotating_tank/input/data}
202 afe 1.2 \end{small}
203 afe 1.1
204     \subsubsection{File {\it input/data.pkg}}
205     \label{www:tutorials}
206    
207     This file uses standard default values and does not contain
208 afe 1.3 customizations for this experiment.
209 afe 1.1
210     \subsubsection{File {\it input/eedata}}
211     \label{www:tutorials}
212    
213     This file uses standard default values and does not contain
214 afe 1.3 customizations for this experiment.
215 afe 1.1
216 afe 1.6 \subsubsection{File {\it input/thetaPol.bin}}
217 afe 1.1 \label{www:tutorials}
218    
219 afe 1.6 The {\it input/thetaPol.bin} file specifies a three-dimensional ($x,y,z$)
220 afe 1.10 map of initial values of $\theta$ in degrees Celsius. This particular
221     experiment is set to random values x around 20C to provide initial
222     perturbations.
223 afe 1.1
224 afe 1.6 \subsubsection{File {\it input/bathyPol.bin}}
225 afe 1.1 \label{www:tutorials}
226    
227    
228 afe 1.6 The {\it input/bathyPol.bin} file specifies a two-dimensional ($x,y$)
229 afe 1.1 map of depth values. For this experiment values are either
230 afe 1.6 $0m$ or {\bf -delZ}m, corresponding respectively to outside or inside of
231     the tank. The file contains a raw binary stream of data that is enumerated
232 afe 1.1 in the same way as standard MITgcm two-dimensional, horizontal arrays.
233    
234     \subsubsection{File {\it code/SIZE.h}}
235     \label{www:tutorials}
236    
237     Two lines are customized in this file for the current experiment
238    
239     \begin{itemize}
240    
241     \item Line 39,
242 afe 1.7 \begin{verbatim} sNx=120, \end{verbatim} this line sets
243 afe 1.1 the lateral domain extent in grid points for the
244     axis aligned with the x-coordinate.
245    
246     \item Line 40,
247 afe 1.7 \begin{verbatim} sNy=31, \end{verbatim} this line sets
248 afe 1.1 the lateral domain extent in grid points for the
249     axis aligned with the y-coordinate.
250    
251     \end{itemize}
252    
253     \begin{small}
254 afe 1.7 \input{part3/case_studies/rotating_tank/code/SIZE.h}
255 afe 1.1 \end{small}
256    
257     \subsubsection{File {\it code/CPP\_OPTIONS.h}}
258     \label{www:tutorials}
259    
260     This file uses standard default values and does not contain
261 afe 1.3 customizations for this experiment.
262 afe 1.1
263    
264     \subsubsection{File {\it code/CPP\_EEOPTIONS.h}}
265     \label{www:tutorials}
266    
267     This file uses standard default values and does not contain
268 afe 1.3 customizations for this experiment.
269 afe 1.2

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