source: palm/trunk/TUTORIAL/SOURCE/topography.tex @ 1556

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update of tutorial files and figures

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[973]1%$Id: topography.tex 1541 2015-01-28 11:14:05Z maronga $
2\input{header_tmp.tex}
3%\input{../header_lectures.tex}
4
5\usepackage[utf8]{inputenc}
6\usepackage{ngerman}
7\usepackage{pgf}
8\usepackage{subfigure}
9\usepackage{units}
10\usepackage{multimedia}
11\usepackage{hyperref}
12\newcommand{\event}[1]{\newcommand{\eventname}{#1}}
13\usepackage{xmpmulti}
14\usepackage{tikz}
15\usetikzlibrary{shapes,arrows,positioning,decorations.pathreplacing}
16\def\Tiny{\fontsize{4pt}{4pt}\selectfont}
17
18%---------- neue Pakete
19\usepackage{amsmath}
20\usepackage{amssymb}
21\usepackage{multicol}
22\usepackage{pdfcomment}
23\usepackage{xcolor}
[1541]24\usepackage{tabto}
[973]25
[1515]26\institute{Institute of Meteorology and Climatology, Leibniz UniversitÀt Hannover}
27\selectlanguage{english}
[973]28\date{last update: \today}
29\event{PALM Seminar}
30\setbeamertemplate{navigation symbols}{}
31\setbeamersize{text margin left=.5cm,text margin right=.2cm}
32\setbeamertemplate{footline}
33  {%
34    \begin{beamercolorbox}[rightskip=-0.1cm]&
35     {\includegraphics[height=0.65cm]{imuk_logo.pdf}\hfill \includegraphics[height=0.65cm]{luh_logo.pdf}}
36    \end{beamercolorbox}
37    \begin{beamercolorbox}[ht=2.5ex,dp=1.125ex,%
38      leftskip=.3cm,rightskip=0.3cm plus1fil]{title in head/foot}%
39      {\leavevmode{\usebeamerfont{author in head/foot}\insertshortauthor} \hfill \eventname \hfill \insertframenumber \; / \inserttotalframenumber}%
40    \end{beamercolorbox}%
41%    \begin{beamercolorbox}[colsep=1.5pt]{lower separation line foot}%
42%    \end{beamercolorbox}
43  }%\logo{\includegraphics[width=0.3\textwidth]{luhimuk_logo.eps}}
44
45\title[PALM - Using Topography]{PALM - Using Topography}
[1515]46\author{PALM group}
[973]47
48% Notes:
49% jede subsection bekommt einen punkt im menu (vertikal ausgerichtet.
50% jeder frame in einer subsection bekommt einen punkt (horizontal ausgerichtet)
51\begin{document}
52% Folie 1
53\begin{frame}
54\titlepage
55\end{frame}
56
[1515]57
[973]58% Folie 2
59\begin{frame}
60   \frametitle{Contents – Using Topography (I)}
61   \begin{itemize}
62      \item{Purpose of topography in PALM} 
63      \item{Realization}
64      \begin{itemize}
[1541]65         \item{Definition}
[973]66         \item{Physical concept}
67         \item{Technical / numerical implementation}
[1541]68         \item{Strengths and limitations}
[973]69      \end{itemize}
70      \item{Control parameters}
71      \begin{itemize}
72         \item{Required / optional topography parameters}
73         \item{Topography-related general control parameters}
74         \begin{itemize}
75            \item{Suitable driving methods, initial and boundary conditions}
76            \item{Pressure solver}
77         \end{itemize}
78      \end{itemize}
79      \item{Data output}
80   \end{itemize}
81\end{frame}
82
[1541]83\section{Purpose}
84\subsection{Purpose}
85
[973]86% Folie 3
87\begin{frame}
88   \frametitle{Purpose of Topography}
89   \begin{itemize}
90      \item{Optional feature to simulate flow around/above obstacles}
91      \par\bigskip
92      \item{Application fields}
93      \begin{itemize}
94         \item{Urban meteorology, wind engineering}
95         \item{Mesoscale meteorology}
96         \item{Oceanography}
97         \item{...}
98      \end{itemize} 
99   \end{itemize}
100\end{frame}
101
[1541]102\section{Realization}
103\subsection{Realization}
104
[973]105% Folie 4
106\begin{frame}
107   \frametitle{Definition}   
108   \begin{itemize}
[1541]109      \item{Topography in PALM covers solid, impermeable, fixed flow obstacles with a volume of at least one grid box.}
[973]110      \par\bigskip
[1541]111      \item{Following qualifies as topography: \textcolor{green!50!black!100}{\checkmark}}     
[973]112      \begin{itemize}
113         \footnotesize
[1541]114         \item{Artificial obstacles (buildings)}
[973]115         \item{Natural obstacles (hills, mountains)}
116      \end{itemize}
117      \par\bigskip
118      \item{The following does NOT qualify as topography: \textcolor{red}{$\times$}}
119      \begin{itemize}
120         \footnotesize
121         \item{\begin{tabbing}Permeable obstacles (vegetation) $\}$  \= Parameterization options in PALM: \\
122                                                                     \> canopy model, local roughness length  \end{tabbing} } 
123         \item{Small obstacles (signposts)}
[1541]124         \item{Moving obstacles (vehicles, wind turbine rotors)}                                                   
[973]125      \end{itemize}
126   \end{itemize}
127\end{frame}
128
129% Folie 5
130\begin{frame}
131   \frametitle{Realization - Physical Concept}
132   \scriptsize
133   \begin{columns}[c]
134   \column{0.8\textwidth}
135      \begin{itemize}
136         \item{Flow cannot enter topography and is forced around/above it.}
137      \end{itemize}
138   \column{0.2\textwidth}
139   \end{columns}
140   \begin{columns}[c]
[1541]141   \column{0.4\textwidth}
[973]142      \begin{itemize}
143         \item{Grid boxes are}
144         \begin{itemize}
[1541]145            \item{\begin{minipage}{0.4\textwidth} \scriptsize
[973]146                     \par\medskip
[1541]147                     100\% \\free fluid, \\
[973]148                  \end{minipage}}
[1541]149            \item{\begin{minipage}{0.4\textwidth} \scriptsize
150                     100\% \\fluid adjacent to an obstacle, or
[973]151                  \end{minipage}}     
[1541]152            \item{\begin{minipage}{0.4\textwidth} \scriptsize
[973]153                     \par\medskip
154                     100\% obstacle. \\
155                  \end{minipage}}             
156         \end{itemize}
[1541]157      \end{itemize}
158   \column{0.6\textwidth}
159      \vspace{-2.cm}\includegraphics[angle=90,width=.9\textwidth]{topography_figures/physical_concept.eps}
160   \end{columns}
161   \begin{columns}[c]
162   \column{1.\textwidth}
163      \begin{itemize}
[973]164         \item{No-slip boundary condition}
165         \begin{itemize}
[1541]166            \item{\scriptsize Wall-normal velocity component is zero at obstacle surface}
[973]167         \end{itemize}
168         \par\bigskip
[1541]169         \item{\begin{minipage}{0.8\textwidth}  \scriptsize
170                  Local surface layer for the first grid box adjacent to each obstacle surface
[973]171               \end{minipage}
172               \begin{minipage}{0.1\textwidth}
[1541]173                  \includegraphics[width=0.35\textwidth]{topography_figures/physical_concept_small.eps}
[973]174               \end{minipage}}
175         \par\smallskip
176         \begin{itemize}
177            \item{\scriptsize Neutral Monin-Obukhov similarity}
178         \end{itemize}
179      \end{itemize}
180   \end{columns}
181\end{frame}
182
183% Folie 6
184\begin{frame}
185   \frametitle{Realization - \\ Numerical /Technical Implementation (I)}
186   \small
187   \begin{columns}[c]
[1541]188   \column{0.65\textwidth}
[973]189      \begin{itemize}
190         \item{Obstacles must be surface-mounted}
[1541]191         \item{Overhanging structures \textbf{\textcolor{blue}{$\times$}}, holes \textbf{\textcolor{red}{$\times$}} etc. are not permitted.}
[973]192         \begin{itemize}
193            \footnotesize
[1541]194            \item{This simplification allows extra performance optimization by reducing the 3D obstacle structure to a "'2.5D"' structure.}
195            \item{"'2.5D"' means that each surface grid cell is assigned only one building-height value (in m).}
[973]196            \item{This conforms to the "'2.5D"' format of Digital Elevation Models (DEM).}
197         \end{itemize}
198      \end{itemize}     
[1541]199   \column{0.3\textwidth}
[973]200      \par\medskip
[1541]201      \includegraphics[width=1.\textwidth]{topography_figures/technical_implementation.eps}
202   \column{0.05\textwidth}
203      \vspace*{2cm}\textcolor{red}{$\times$}
204      \textcolor{green!50!black!100}{\checkmark}
[973]205   \end{columns}
206\end{frame}
207
208% Folie 7
209\begin{frame}
210   \frametitle{Realization - \\ Numerical /Technical Implementation (II)}
[1541]211   \small
[973]212   \begin{columns}[c]
[1541]213   \column{0.5\textwidth}
214      \begin{itemize}
215         \item{The location of the wall-normal velocity component defines the location of the impermeable obstacle surface}
216         \item{Obstacle surfaces that do not match the grid are approximated by grid boxes like a step-function}
217      \end{itemize}
[973]218      \par\bigskip
[1541]219      \hspace{1cm}$\bullet$ scalars \\
220      \hspace{1cm}\textcolor{red}{$\bullet$ u (staggered)} \\
221      \hspace{.92cm}\textcolor{green!40!black!100}{\textbf{+} v (staggered)}
222   \column{0.5\textwidth}
223      \includegraphics[width=\textwidth]{topography_figures/technical_implementation_grid/technical_implementation_grid_5.png}
[973]224   \end{columns}
225\end{frame}
226
227% Folie 8
228\begin{frame}
229   \frametitle{Realization - \\ Numerical / Technical Implementation (III)}
230   \footnotesize
231   \textbf{Rastering GIS data: \dq from GIS data to ASCII raster data\dq}
232   \begin{itemize}
233      \item{In order to process topography from external data sources, the data must be made available
[1541]234            to PALM as a rastered ASCII file:}
235      \begin{itemize}
236         \item{see e.g. {\tt trunk/EXAMPLES/topo\_file/example\_topo\_file\_topo}.} 
237      \end{itemize}
238      \item{The layout of this topography file must conform to the computational domain size and to the grid size {\tt dx} and {\tt dy}.}
239      \item{The rastered height data of this topo file are given in m above ground and do not need to match
[1226]240            the vertical grid, since they will be interpolated, if required.}
[973]241      \par\bigskip
242      \item{Software known to be able to perfom the rastering process of GIS data in vector and/or raster format to PALM raster format:}
243      \begin{itemize}
244         \item{ArcGIS (commercial)}
245         \item{GRASS GIS (freeware)}
246      \end{itemize}
247   \end{itemize}
248\end{frame}
249
250% Folie 9
251\begin{frame}
252   \frametitle{Realization – \\ Numerical / Technical Implementation (IV)} 
253   \small
[1541]254   \textbf{Potential issue: Load imbalance}
255   \begin{columns}[c]
256   \column{0.55\textwidth}
[973]257      \begin{itemize}
[1541]258         \item{Since prognostic equations are not calculated inside buildings, \\ \textbf{load imbalance} might occur, if topography is heterogeneously distributed among the subdomains.}
[973]259         \begin{itemize}
[1541]260          \item{This means \dq fast\dq CPU(s) must wait for \dq slow\dq CPU(s), leading to inefficient parallelization.}
[973]261         \end{itemize}
[1541]262      \end{itemize}
263   \column{0.45\textwidth}
264      \includegraphics[angle=90,width=\textwidth]{topography_figures/load_imbalance.eps}
265   \end{columns}
[973]266\end{frame}
267
268% Folie 10
269\begin{frame}
270   \frametitle{Summary: Strengths (+) and Limitations (–)}
271   \small
272   \begin{itemize}
273      \item[+]{Horizontal and vertical surfaces can be exactly resolved (thanks to the finite difference Cartesian model architecture)}
274      \item[+]{Optimization also for scalar computer architectures}
275      \item[+]{Conforms with \dq 2.5D\dq format of Digital Elevation Models (DEM)} 
276      \par\bigskip
[1541]277      \item[$-$]{Obstacles must be surface-mounted}
278      \item[$-$]{Overhanging structures, holes etc. are not permitted due to the \dq 2.5D\dq format}
279      \item[$-$]{Grid boxes can only be 100\% fluid or 100\% obstacle \\ \par\smallskip
280                \begin{footnotesize} Obstacle surfaces that do not match the grid are approximated by grid boxes like a step-function, which can modify the real obstacle size or the orientation of the obstacle faces\end{footnotesize}}
[973]281   \end{itemize}
282\end{frame}
283
284% Folie 11
285\begin{frame}
286   \frametitle{Take a Short Break... Urban Flow Visualization}
287   \begin{columns}[c]
[1541]288   \column{0.5\textwidth}
289      \includegraphics<1->[width=.8\textwidth]{topography_figures/hannover_1.png}
290      \par\smallskip
291      \href{.html}{\includegraphics<2->[width=.8\textwidth]{topography_figures/hannover_2.png}}
292   \column{0.5\textwidth}
293      \par\smallskip
294      \footnotesize
295      \uncover<1->{Set-up: neutral boundary layer}
[973]296      \begin{itemize}
[1541]297         \uncover<1->{\item{Particle = passive tracer}}
298         \uncover<1->{\item{Colour $\sim$ particle height}}
299         \uncover<1->{\item{Tail length ~ particle velocity}}         
300      \end{itemize} 
[973]301      \begin{itemize}
[1541]302         \uncover<2>{\item{Flow past office tower:}}
[973]303         \begin{itemize}
[1541]304            \uncover<2>{\item{initially laminar: not yet an LES}}
305            \uncover<2>{\item{intermittent: different episodes}}
[973]306         \end{itemize}
[1541]307         \uncover<2>{\item{Broad street canyon flow:}}
[973]308         \begin{itemize}
[1541]309            \uncover<2>{\item{channeling}}
310            \uncover<2>{\item{low-level upstream flow}}
[973]311         \end{itemize}
312      \end{itemize}
313   \end{columns}
314\end{frame}
315
[1541]316\section{Control parameters}
317\subsection{Control parameters}
318
[973]319% Folie 12
320\begin{frame}
321   \frametitle{Required Topography Control Parameters}
[1541]322    \scriptsize
323   \uncover<1->{{\tt topography =}}
[973]324   \begin{itemize}
[1541]325      \uncover<1->{\item{{\tt 'flat'}                   \tabto{4cm} no topography (default)}}
326      \uncover<1->{\item{{\tt 'single\_building'}       \tabto{4cm} \textcolor{red}{generic} single building}}
327      \uncover<1->{\item{{\tt 'single\_street\_canyon'} \tabto{4cm} \textcolor{red}{generic} single quasi-2D street canyon}}
328      \uncover<1->{\item{{\tt 'read\_from\_file'}       \tabto{4cm} \textcolor{blue}{rastered} ASCII file \\ \tabto{4cm}(e.g. {\tt trunk/EXAMPLES/topo\_file})}}
329      \uncover<1->{\item{any other string               \tabto{4cm} processed by user subroutine user\_init\_grid}}
[973]330   \end{itemize}
[1541]331   \uncover<2->{{\tt topography\_grid\_convention =}}
[973]332   \begin{itemize}
[1541]333      \uncover<2->{\item{{\tt '\textcolor{red}{cell\_edge}'}    \tabto{4cm} default for \textcolor{red}{generic} topography: \textcolor{red}{$\leftrightarrow$}}}
334      \uncover<3->{\item{{\tt '\textcolor{blue}{cell\_center}'} \tabto{4cm} default for \textcolor{blue}{rastered} topography: \textcolor{blue}{$\bigcirc$ $\leftrightarrow$}}}
[973]335   \end{itemize}
[1541]336   \includegraphics<2|handout:0>[width=0.4\textwidth]{topography_figures/control_parameters_2.png}
337   \includegraphics<3|handout:1>[width=0.4\textwidth]{topography_figures/control_parameters_4.png}
[973]338\end{frame}
339
340% Folie 13
341\begin{frame}
342   \frametitle{Optional Topography Control Parameters (I)}
343   \small
[1541]344   \textbf{Generic topography}
345   \begin{figure}
346      \centering\includegraphics[width=.8\textwidth]{topography_figures/single_building_parameters.eps}
347   \end{figure}
[973]348\end{frame}
349
350% Folie 14
351\begin{frame}
352   \frametitle{Optional Topography Control Parameters (II)}
[1541]353   \small
354   \textbf{Generic topography}
355   \begin{figure}
356      \centering\includegraphics[width=.8\textwidth]{topography_figures/single_canyon_parameters.eps}
357   \end{figure}
358\end{frame}
359
360% Folie 15
361\begin{frame}
362   \frametitle{Optional Topography Control Parameters (III)}
[973]363   \scriptsize   
364   \textbf{Rastered topography}\\
[1541]365   \begin{minipage}{0.8\textwidth}
[973]366      \begin{itemize}
367         \scriptsize
368         \item{{\tt topography} = 'read\_from\_file'} 
369         \begin{itemize}
370            \footnotesize
371            \item{requires an external ASCII file, e.g. {\tt example\_topo:}}
372         \end{itemize}
373      \end{itemize}
374   \end{minipage}
[1541]375   \begin{minipage}{0.15\textwidth}
[973]376      \includegraphics[width=0.5\textwidth]{topography_figures/optional_control_parameters_1.png}
377   \end{minipage}
378   \begin{center}
[1541]379      \includegraphics[width=0.75\textwidth]{topography_figures/optional_control_parameters_2.png}
[973]380   \end{center}
381   \begin{itemize}
382      \item[]{}
383      \begin{itemize} 
[1541]384         \scriptsize
385         \item{ASCII file {\tt example\_topo} must be available as INPUT file, like {\tt example\_p3d} ({\tt JOBS/example/INPUT/})}     
386         \item{layout must conform to domain size and grid size {\tt dx} and {\tt dy}}
387         \item{height data in m above ground (INTEGER or REAL) do not need to match the vertical grid}
[973]388      \end{itemize}
389   \end{itemize}
390\end{frame}
391
[1541]392% Folie 16
[973]393\begin{frame}
[1541]394   \frametitle{Optional Topography Control Parameters (IV)}
[973]395   \small
396   \textbf{Rastered topography}
397   \begin{itemize}
398      \item{{\tt topography} = 'read\_from\_file'}
399      \par\smallskip
400      \begin{itemize}
401         \item{\textbf{mrun}-call: \\
402               {\tt mrun ... -r 'd3\# ...'}}
403         \par\medskip
404         \item{{\tt .mrun.config:}}
405      \end{itemize}
406   \end{itemize} 
407   \begin{center} \includegraphics[width=0.7\textwidth]{topography_figures/optional_control_parameters_3.png} \end{center}
408\end{frame}
409
[1541]410% Folie 17   
[973]411\begin{frame}
412   \frametitle{General Control Parameters (I): Suitable Driving Methods}
413   \scriptsize
414   \begin{itemize}
415      \item{\textbf{\dq Meteorological\dq set-up M: geostrophic wind / Coriolis force}}
416      \begin{itemize}
417         \scriptsize
418         \item{Set {\tt omega $ \neq$ 0.0}}
419         \item{Construct a non-zero profile of geostrophic wind $u_g$ and/or $v_g$ using {\tt ug\_surface}, {\tt ug\_vertical\_gradient}
420               and {\tt ug\_vertical\_gradient\_level} and/or the respective parameter set for $v_g$}
421      \end{itemize}
422      \par\bigskip
423      \item{\textbf{\dq Engineering\dq set-up E: direct external pressure gradient / no Coriolis force}}
424      \begin{itemize}
425         \scriptsize
426         \item{Set {\tt omega = 0.0}}
427         \item{Set-up E1: direct external pressure gradient that does not change with time
428                 (the bulk velocity fluctuates with time)}
429         \begin{itemize}
430            \scriptsize
431            \item{Parameters: {\tt dp\_external}, {\tt dp\_smooth}, {\tt dp\_level\_b}, {\tt dpdxy}}
432         \end{itemize}
433         \item{Set-up E2: maintain a constant bulk velocity
434                 (the direct external pressure gradient fluctuates with time)}
435         \begin{itemize}
436             \scriptsize
437             \item{Parameters: {\tt conserve\_volume\_flow}, {\tt conserve\_volume\_flow\_mode}, {\tt u\_bulk}, {\tt v\_bulk}}
438         \end{itemize}
439      \end{itemize}
440      \par\bigskip
441      \item{\textbf{\dq Thermal\dq set-up T: directly prescribe sensible heatflux}}
442      \begin{itemize}
443         \item[]{}
444         \begin{itemize}
445            \scriptsize
446            \item{surface\_heatflux at ground level only} 
447            \item{wall\_heatflux(0:4) at top/left/right/South/North obstacle face}
448         \end{itemize}
449      \end{itemize}
450   \end{itemize}
451\end{frame}
452
[1541]453% Folie 18
[973]454\begin{frame}
455   \frametitle{General Control Parameters (II): Initialization}
456   \scriptsize
457   \begin{itemize}
458      \item{\textbf{\dq Meteorological\dq set-up M }\\
459            Initialize a non-zero profile of geostrophic wind $u_g$ and/or $v_g$ using}
460      \begin{itemize}
461         \scriptsize
462         \item{{\tt initializing\_actions =} \textbf{'set\_constant\_profiles' (e.g. for convective BL)}}
463         \begin{itemize}
464            \scriptsize
465            \item{Parameters: {\tt ug\_surface $ \neq $ 0.0} and/or {\tt vg\_surface $\neq $ 0.0}}
466         \end{itemize}
467         \item{{\tt initializing\_actions =} \textbf{'set\_1d-model\_profiles' (e.g. for neutral BL)}}
468         \begin{itemize}
469            \scriptsize
470            \item{1D model prerun parameters with suffix {\tt \_1d} (e.g. {\tt end\_time\_1d}, {\tt damp\_level\_1d)}}
471         \end{itemize}
472      \end{itemize} 
473      \par\bigskip
474      \item{\textbf{\dq Engineering\dq set-up E} \\
475            Good initialization may require a priori knowlegde, e.g. from previous test runs.
476            Here, {\tt ug\_}... and {\tt vg\_}... don't refer to geostrophic wind but to the initial wind profile.} 
477      \begin{itemize}
478         \scriptsize
479         \item{{\tt initializing\_actions} = \textbf{'set\_constant\_profiles'}}
480         \begin{itemize}
481            \scriptsize
482            \item{Parameter set: {\tt ug\_surface}, {\tt ug\_vertical\_gradient}[{\tt \_level}] and/or the respective set for $v_g$}
483         \end{itemize}
484         \item{{\tt initializing\_actions} = \textbf{'set\_1d-model\_profiles'}}
485         \item{{\tt initializing\_actions} = \textbf{'by\_user' – processed by user\_init\_3d\_model}}
486      \end{itemize}
487      \par\bigskip
488      \item{\textbf{\dq Thermal\dq set-up T} \\
489            Any of the above may apply}
490   \end{itemize}
491\end{frame}
492
[1541]493% Folie 19
[973]494\begin{frame}
495   \frametitle{General Control Parameters (III): Boundary Conditions}
496   \footnotesize
497   \begin{itemize}
498      \item{Lateral boundary conditions}
499      \begin{itemize}
500         \item{Cyclic / non-cyclic: cf. lecture on \dq non-cyclic boundary conditions\dq}
501      \end{itemize} 
502      \item{Bottom boundary conditions}
503      \begin{itemize}
504         \item{Cf. lecture on \dq numerics and boundary conditions\dq}
505      \end{itemize}
506      \item{Top boundary conditions}
507      \begin{itemize}
508         \footnotesize
509         \item{\textbf{Channel}: {\tt bc\_uv\_t =} \textbf{'dirichlet\_0' (no-slip)}}
510         \item{\textbf{Open channel}: {\tt bc\_uv\_t =} \textbf{'neumann' (slip)}}
[1515]511         \item{\textbf{\dq Constant flux\dq layer}: {\tt bc\_uv\_t =} \textbf{'neumann' (slip)} \\
[973]512                with set-up E1 where {\tt dp\_level\_b >> 0} and {\tt dp\_smooth = .T.}}
513      \end{itemize}
514   \end{itemize}
515\end{frame}
516
[1541]517% Folie 20
[973]518\begin{frame}
519   \frametitle{General Control Parameters (IV): Pressure Solver} 
520   {\tt psolver =}
521   \par\medskip
522   \begin{itemize}
523      \item{'poisfft' (FFT scheme)} 
524      \begin{itemize}
525         \item{Good performance for urban PALM version}
526         \item{Cannot be used with non-cyclic boundary conditions}
527      \end{itemize}
528      \par\bigskip
529      \item{'multigrid' (Multigrid scheme)}
530      \begin{itemize}
531         \item{Performance for very large number of grid points may be better than FFT}
532         \item{This is the only possible choice for non-cyclic boundary conditions}
533      \end{itemize}
534   \end{itemize}
535\end{frame}
536
[1541]537\section{Data output/ Scenarios}
538\subsection{Data output/ Scenarios}
539
540% Folie 21
[973]541\begin{frame}
542   \frametitle{Data Analysis / Output – Some Considerations (I)}
543   \scriptsize
544   \begin{itemize}
545      \item{How to get turbulence statistics?}
546      \begin{itemize}
547         \scriptsize
548         \item{Phase averaging if a direction of homogeneity exists}
549         \item{Temporal averaging}
550         \item{Ensemble averaging}
551      \end{itemize} 
552      \item{Definition of turbulent fluctuations}\\
553      \textbf{Spatial fluctuations:} deviation from representative instantaneous spatial average
554      \begin{itemize}
555         \scriptsize
556         \item{PALM: many statistics calculated on-the-fly as time series, 1D vertical profiles}
557         \item{Not suitable for topography unless a direction of homogeneity exists}
558      \end{itemize}
559      \textbf{Temporal fluctuations}: deviation from representative local temporal average
560      \begin{itemize}
561         \scriptsize
562         \item{Suitable for all applications including topography}
563         \item{Requires much hard disk space and post-processing CPU time}
564         \item{PALM: not natively supported, but following procedure works:}
565         \begin{itemize}
566            \scriptsize
567            \item{Collect time-series during the simulation (2D/3D data output or user-defined time series)}
568            \item{Check for (quasi-)steady turbulent state and sufficient averaging time}
569            \item{Calculate statistics by post-processing making use of the Reynolds decomposition: \\ \par\medskip
570                  $\overline{w'\theta'} = \overline{w\theta} - \overline{w} \overline{\theta} $}
571         \end{itemize}
572      \end{itemize}   
573   \end{itemize}
574\end{frame}
575
[1541]576% Folie 22
[973]577\begin{frame}
578   \frametitle{Your Responsibility and Contribution}
579   \footnotesize
580   \par\medskip
[1515]581   PALM's topography features have been frequently applied within the last years, but there may be still some parameter combinations which have not been used so far, and which may not work properly.
[973]582   \par\bigskip
[1226]583%    For example, the combination of topography and non-cyclic lateral boundary conditions has not yet been tested
584%    because both features have originally been introduced separately for different research projects.
585%    \par\bigskip
[973]586   Therefore, we ask you for your responsibility and contribution:
587   \begin{itemize}
588      \item{Please always check your PALM setup carefully. PALM is not a black box.} 
589      \item{For example, design a simple case and test your expectation.}
[1515]590      \item{Please report potential bugs using our trouble ticket system.}
[973]591   \end{itemize}
592\end{frame}
593
[1541]594% Folie 23
[973]595\begin{frame}
[1515]596   \frametitle{Some recent examples of topography/building applications with PALM}
597   
598   \scriptsize
599   \textbf{Street canyon flows}
600   \par\smallskip
601   \tiny
602   \textbf{Letzel, M.O., M. Krane and S. Raasch 2008}: High resolution urban large-eddy simulation studies from street canyon to neighbourhood scale, Atmos. Env.,
603   \textbf{42}, 8770-8784, doi:10.1016/j.atmosenv.2008.08.001.\\
604   \par\medskip
605
606   \scriptsize
607   \textbf{Turbulence generated by topography}
608   \par\smallskip
609   \tiny
610   \textbf{Esau, I. and I. Repina, 2012}: Wind climate in Kongsfjorden, Svalbard, and attribution of leading wind driving mechanisms through turbulence-resolving simulations. Advances in Meteorology,
611   \textbf{Volume 2012}, Article ID 568454, 16 pages, doi:10.1155/2012/568454.\\
612   \par\medskip
613   
614   \scriptsize
615   \textbf{Airflow within or over building arrays}
616   \par\smallskip
617   \tiny
618   \textbf{Abd Razak A., A. Hagishima, N. Ikegaya and J. Tanimoto, 2013}: Analysis of airflow over building arrays for assessment of urban wind environment. Building and Environment,
619   \textbf{59}, 56-65, doi:10.1016/j.buildenv.2012.08.007. \\
620   \par\smallskip
621   \textbf{Kanda, M., A. Inagaki, T. Miyamoto, M. Gryschka and S. Raasch 2013}: A New Aerodynamic Parameterization for Real Urban Surfaces, Boundary-Layer Meteorol.,
622    \textbf{148}, 357-377, doi:10.1007/s10546-013-9818-x. \\
623   \par\medskip
624       
625   \scriptsize
626   \textbf{Thermal effects of building walls}
627   \par\smallskip
628   \tiny
629   \textbf{Park, S.B., J.J. Baik, S. Raasch and M.O. Letzel 2012}: A large-eddy simulation study of thermal effects on turbulent flow and dispersion in and above a street canyon., J. Appl. Meteor. Climatol.,
630   \textbf{51}, 829-841, doi:10.1175/JAMC-D-11-0180.1.\\
631   \par\medskip
632
633   \scriptsize
634   \textbf{PALM coupled to a building energy model}
635   \par\smallskip
636   \tiny
637   \textbf{Yaghoobian, N., J. Kleissl and K. T. Paw U, 2014}: An Improved Three-Dimensional Simulation of the Diurnally Varying Street-Canyon Flow, Boundary-Layer Meteorol.,
638   doi:http://dx.doi.org/10.1007/s10546-014-9940-4.\\
639\end{frame}
640
[1541]641% Folie 24
[1515]642\begin{frame}
[973]643   \Large
644   \begin{center} \textcolor{blue!90!black!100}{Topography - Scenario examples} \end{center}
645\end{frame}
646
[1541]647% Folie 25
[973]648\begin{frame}
649   \frametitle{Set-up Scenario: Single Street Canyon (I)}
650   \par\smallskip
651   \textbf{Single quasi-2D street canyon in neutral open channel flow with constant bulk velocity}
652   \par\smallskip
653   \begin{itemize}
654      \item{{\tt trunk/EXAMPLES/canyon/}}
655      \begin{itemize}
656         \item{Parameter file \hspace{2cm} {\tt example\_canyon\_p3d}}
657         \item{Run-control file \hspace{1.78cm} {\tt example\_canyon\_rc}}
658         \item{Some documentation \hspace{0.95cm} {\tt example\_canyon.odt}}
659      \end{itemize}
660   \end{itemize}
661   \begin{center}
662      \includegraphics[width=0.85\textwidth]{topography_figures/scenario_ssc_1.png}
663   \end{center}
664\end{frame}
665
[1541]666% Folie 26
[973]667\begin{frame}
668   \frametitle{Set-up Scenario: Single Street Canyon (II)}
669   \textbf{The phase average makes use of homogeneity in y-direction:} \\
670   {\tt section\_xz = -1}, {\tt data\_output = \textbf{'u\_xz\_av'}}, {\tt 'v\_xz\_av'}, {\tt 'w\_xz\_av'}
671   \begin{center}
672      \includegraphics[width=0.85\textwidth]{topography_figures/scenario_ssc_2.png}
673   \end{center}
674\end{frame}
675
[1541]676% Folie 27
[973]677\begin{frame}
678 \begin{tikzpicture}[remember picture, overlay]
679      \node [shift={(6.5 cm, 5cm)}]  at (current page.south west)
680         {%
681         \begin{tikzpicture}[remember picture, overlay]
[1541]682            \uncover<1>{\node at (2.75,-0.5) {\includegraphics[width=0.55\textwidth]{topography_figures/scenario_ssc_example_2.png}};}
683            \uncover<1>{\node at (-3.25,-0.5) {\includegraphics[width=0.55\textwidth]{topography_figures/scenario_ssc_example_1.png}};}
[973]684         \end{tikzpicture}
685         };
686  \end{tikzpicture}
687\end{frame}
688
[1541]689% Folie 28
[973]690\begin{frame}
[1541]691 \begin{tikzpicture}[remember picture, overlay]
692      \node [shift={(6.5 cm, 5cm)}]  at (current page.south west)
693         {%
694         \begin{tikzpicture}[remember picture, overlay]
695            \uncover<1>{\node at (2.75,-0.5) {\includegraphics[width=0.55\textwidth]{topography_figures/scenario_ssc_example_2.png}};}
696            \uncover<1>{\node at (-3.25,-0.5) {\includegraphics[width=0.55\textwidth]{topography_figures/scenario_ssc_example_1.png}};}
697            \uncover<1>{\node at (3.5,-0.2) {\includegraphics[width=0.38\textwidth]{topography_figures/scenario_ssc_example_5.png}};}
698            \uncover<2>{\node at (-3.5,-0.2) {\includegraphics[width=0.48\textwidth]{topography_figures/scenario_ssc_example_4.png}};}
699         \end{tikzpicture}
700         };
701  \end{tikzpicture}
702\end{frame}
703
704% Folie 29
705\begin{frame}
[973]706   \frametitle{Set-up Scenario: Constant Flux Layer}
707   \small
708   \textbf{Single surface-mounted cube in neutral open channel flow with a constant flux layer}
709   \begin{itemize}
710      \item{{\tt trunk/EXAMPLES/constant\_flux\_layer/}}
711      \begin{itemize}
712         \footnotesize
713         \item{Parameter file \hspace{2cm} {\tt example\_constant\_flux\_layer\_p3d}}
714         \item{Run-control file \hspace{1.79cm} {\tt example\_constant\_flux\_layer\_rc}}
715         \item{Some documentation \hspace{1.02cm} {\tt example\_constant\_flux\_layer.odt}}
716      \end{itemize}
717   \end{itemize}
718   \begin{center}
719      \includegraphics[width=0.85\textwidth]{topography_figures/scenario_cfl.png}
720   \end{center}
721\end{frame}
722
[1541]723% Folie 30
[973]724\begin{frame}
725 \begin{tikzpicture}[remember picture, overlay]
726      \node [shift={(6.5 cm, 5cm)}]  at (current page.south west)
727         {%
728         \begin{tikzpicture}[remember picture, overlay]
729            \uncover<1->{\node at (0,-0.5) {\includegraphics[width=0.7\textwidth]{topography_figures/scenario_cfl_example_1.png}};}
[1541]730         \end{tikzpicture}
731         };
732  \end{tikzpicture}
733\end{frame}
734
735% Folie 31
736\begin{frame}
737 \begin{tikzpicture}[remember picture, overlay]
738      \node [shift={(6.5 cm, 5cm)}]  at (current page.south west)
739         {%
740         \begin{tikzpicture}[remember picture, overlay]
741            \uncover<1->{\node at (0,-0.5) {\includegraphics[width=0.7\textwidth]{topography_figures/scenario_cfl_example_1.png}};}
742            \uncover<1->{\node at (3.5,-0.2) {\includegraphics[width=0.38\textwidth]{topography_figures/scenario_cfl_example_3.png}};}
[973]743            \uncover<2->{\node at (-3.5,-0.2) {\includegraphics[width=0.45\textwidth]{topography_figures/scenario_cfl_example_2.png}};}
744         \end{tikzpicture}
745         };
746  \end{tikzpicture}
747\end{frame}
748
[1541]749% Folie 32
[973]750\begin{frame}
751   \frametitle{Rules of Good Practise}
752   \small
753   \begin{itemize}
754      \item{If you run PALM with topography, make sure that it is really LES...}
755      \begin{itemize}
756         \item{''Large eddies'' are ''small'' between obstacles}
757         \begin{itemize}
758            \item{use fine grid length to resolve turbulence there}
759         \end{itemize}
760         \item{Ratio of resolved to SGS fluxes}
761      \end{itemize} 
762      \item{Check for (quasi-)steady turbulent state and sufficient averaging time.}
763      \begin{itemize}
764         \item{Fluctuations of time series of E, E*, maximum velocity components etc.}
765      \end{itemize}
766      \item{Make sure that your PALM result is independent of numerical parameters such as domain size and grid size.}
767      \begin{itemize}
768         \item{Sensitivity studies}
769      \end{itemize}
770      \item{If you intend to do a comparison with some kind of reference data, it is essential to configure the set-up of PALM
771           in the same way as the reference experiment.}
772      \begin{itemize}
773         \item{For example, if you compare PALM with wind tunnel results, you have to follow the wind tunnel set-up for setting up PALM.}
774      \end{itemize}
775   \end{itemize}
776\end{frame}
777
[1515]778\end{document}
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