- Timestamp:
- Jan 28, 2015 11:14:05 AM (10 years ago)
- Location:
- palm/trunk/TUTORIAL/SOURCE
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palm/trunk/TUTORIAL/SOURCE/exercise_topography.tex
r1515 r1541 87 87 \frametitle{Questions to be Answered} 88 88 \small 89 \begin{ itemize}90 \item<2->{Can you identify flow convergence / divergence patterns near the cube?}89 \begin{enumerate} 90 \item<2->{Can you identify any interesting flow patterns around the cube and what do they tell us?} 91 91 \begin{itemize} 92 92 \item{What kind of output do you need to answer this?} 93 93 \end{itemize} 94 \item<3->{How does the horizontally and temporally averaged momentum flux profile look 95 like?} 94 \item<3->{How do the horizontally and temporally averaged velocity and momentum flux profiles look like?} 96 95 \begin{itemize} 97 96 \item{How long should the averaging time interval be?} 98 97 \end{itemize} 99 \item<4->{Is it really a large-eddy simulation?}98 \item<4->{Is it really a fully developed large-eddy simulation?} 100 99 \begin{itemize} 101 100 \item{Are the subgrid-scale fluxes much smaller than the resolved-scale fluxes?} … … 103 102 with time?} 104 103 \end{itemize} 105 \end{itemize} 106 \onslide<5->\textbf{Final question:} 107 \begin{itemize} 108 \item{Do the results of both runs agree?} 109 \end{itemize} 104 \item{\onslide<5->\textbf{Final question:} Do the results of both runs agree?} 105 \end{enumerate} 110 106 \end{frame} 111 107 … … 141 137 \item{For constant bulk velocity, see \textbf{conserve\_volume\_flow}.} 142 138 \item{For Coriolis force, see \textbf{omega}.} 139 \item{For neutral flow, see \textbf{neutral}.} 143 140 \end{itemize} 144 141 \item<6->{\textbf{Topography}} … … 214 211 \item<3->[2.]{Check your results to answer all questions â except the final question.} 215 212 \item<4->[3.]{After this run has finished, use ncview, ncdump etc. to check the precise 216 location of the building (look at 2D array zusithat is contained in 2D xy213 location of the building (look at 2D array \textit{zusi} that is contained in 2D xy 217 214 cross-sections and 3D volume data).} 218 215 \item<5->[4.]{Use this information to manually create the ''raster\_topo'' file.} … … 249 246 % Folie 9 250 247 \begin{frame} 251 \frametitle{Flow convergence / divergence (I)} 248 \frametitle{Question 1: Flow patterns (I)} 249 \par\smallskip 250 \footnotesize 251 \textbf{Horizontal cross sections of 1-h averaged velocity components \textit{u} and \textit{v}} 252 252 \includegraphics[width=0.45\textwidth]{exercise_topography_figures/cross_sections/u_xy.eps} \hspace{0.8cm} 253 253 \includegraphics[width=0.45\textwidth]{exercise_topography_figures/cross_sections/v_xy.eps} … … 256 256 % Folie 10 257 257 \begin{frame} 258 \frametitle{Flow convergence / divergence (II)} 258 \frametitle{Question 1: Flow patterns (II)} 259 \par\smallskip 260 \footnotesize 261 \textbf{Horizontal and streamwise vertical cross sections of 1-h averaged \\ velocity component \textit{w}} 262 \par\smallskip 259 263 \includegraphics[width=0.45\textwidth]{exercise_topography_figures/cross_sections/w_xy.eps} \hspace{0.8cm} 260 264 \includegraphics[width=0.45\textwidth]{exercise_topography_figures/cross_sections/w_xz.eps} … … 263 267 % Folie 11 264 268 \begin{frame} 265 \frametitle{Streamlines} 269 \frametitle{Question 1: Flow patterns (III)} 270 \par\smallskip 271 \footnotesize 272 \textbf{Streamlines (1-h average) for the same cross sections as seen in Frame 10 \\ for the \textit{w}-velocity} 273 \par\smallskip 266 274 \includegraphics[width=0.45\textwidth]{exercise_topography_figures/streamlines/streamlines_xy.eps} \hspace{0.8cm} 267 275 \includegraphics[width=0.45\textwidth]{exercise_topography_figures/streamlines/streamlines_xz.eps} \hspace{0.8cm} … … 271 279 % Folie 12 272 280 \begin{frame} 273 \frametitle{Vertical profiles of $\overline{w'u'}$, $\overline{w'v'}$} 281 \frametitle{Question 2: Velocity and momentum flux profiles} 282 \par\smallskip 283 \footnotesize 284 \textbf{Vertical profiles of 1-h and horizontally averaged \textit{u}-, \textit{v}- and \textit{w}-velocity} 285 \par\smallskip 286 \includegraphics[width=\textwidth]{exercise_topography_figures/profiles/profile_uvw.png} 287 \end{frame} 288 289 % Folie 13 290 \begin{frame} 291 \frametitle{Question 2: Velocity and momentum flux profiles} 292 \par\smallskip 293 \footnotesize 294 \textbf{Vertical profiles of 1-h and horizontally averaged total turbulent momentum \\ fluxes $wu$ and $wv$} 295 \par\smallskip 274 296 \includegraphics[width=0.45\textwidth]{exercise_topography_figures/profiles/wu_time_pr.eps} \hspace{0.8cm} 275 297 \includegraphics[width=0.45\textwidth]{exercise_topography_figures/profiles/wv_time_pr.eps} 276 298 \end{frame} 277 299 278 % Folie 13 279 \begin{frame} 280 \frametitle{LES? - Fluxes} 300 % Folie 14 301 \begin{frame} 302 \frametitle{Question 3: LES? - Fluxes} 303 \par\smallskip 304 \footnotesize 305 \textbf{Vertical profiles of 1-h and horizontally averaged momentum fluxes: total ($wu$), resolved-scale ($w^{*}u^{*}$) and subgrid-scale ($w''u''$) fluxes} 306 \par\smallskip 281 307 \begin{center} 282 308 \includegraphics[width=0.6\textwidth]{exercise_topography_figures/profiles/wu_comp_pr.eps} … … 284 310 \end{frame} 285 311 286 % Folie 14 287 \begin{frame} 288 \frametitle{LES? - Time Series (I)} 312 % Folie 15 313 \begin{frame} 314 \frametitle{Question 3: LES? - Time Series (I)} 315 \par\smallskip 316 \footnotesize 317 \textbf{Total kinetic energy \textit{E} of the flow and maximum \textit{u}-velocity in the model domain} 318 \par\smallskip 289 319 \begin{center} 290 320 \includegraphics[width=0.95\textwidth]{exercise_topography_figures/timeseries/E_ts.eps} \\ … … 293 323 \end{frame} 294 324 295 % Folie 15 296 \begin{frame} 297 \frametitle{LES? - Time Series (II)} 325 % Folie 16 326 \begin{frame} 327 \frametitle{Question 3: LES? - Time Series (II)} 328 \par\smallskip 329 \footnotesize 330 \textbf{Maximum \textit{v}- and \textit{w}-velocity in the model domain} 331 \par\smallskip 298 332 \begin{center} 299 333 \includegraphics[width=\textwidth]{exercise_topography_figures/timeseries/vmax_ts.eps} \\ … … 302 336 \end{frame} 303 337 338 \subsection{Answers} 339 340 % Folie 17 341 \begin{frame} 342 \frametitle{Answer to question 1 (I)} 343 \footnotesize 344 \textbf{Can you identify any interesting flow patterns around the cube and what do they tell us?} 345 \par\smallskip 346 \footnotesize 347 The 1-h-averaged near-surface horizontal velocity components \textit{u} and \textit{v} show (see Frame 9): 348 \scriptsize 349 \begin{itemize} 350 \item{reversed streamwise flow in the gap between leeward and windward cube wall,} 351 \item{diverging spanwise flow in the gap with nearly same magnitude as reversed spanwise flow.} 352 \end{itemize} 353 \par\smallskip 354 \footnotesize 355 The \textit{w}-velocity fields complete the picture (see Frame 10), we see: 356 \scriptsize 357 \begin{itemize} 358 \item{descending mean flow near the windward cube wall,} 359 \item{ascending mean flow near the leeward cube wall.} 360 \end{itemize} 361 \end{frame} 362 363 % Folie 18 364 \begin{frame} 365 \frametitle{Answer to question 1 (II)} 366 \footnotesize 367 \textbf{Can you identify any interesting flow patterns around the cube and what do they tell us?} 368 \par\smallskip 369 \footnotesize 370 Streamlines in Frame 11 show an overall view of the mean horizontal (left; near surface) and the mean streamwise-vertical (right; center of cube wall) flow: 371 \scriptsize 372 \begin{itemize} 373 \item{left: in the gap between leeward and windward cube wall, streamlines are directed in opposite direction to the prescribed flow direction, and they diverge in the spanwise direction,} 374 \item{left: starting at the corners of the leeward cube wall, these diverging streamlines converge with the streamlines of the flow forced around the side walls of the cube,} 375 \item{right: above the cube roof, the mean flow is horizontal and directed as prescribed,} 376 \item{right: in the streamwise gap, we find a rotor-like vortex, explaining the mean downward motion in the largest part of the gap, the upward motion at the leeward cube wall, and the reversed streamwise flow, covering almost fully the gap dimensions.} 377 \end{itemize} 378 \par\smallskip 379 \footnotesize 380 \textbf{Note:} Flow patterns can change significantly when the size of the gaps between buildings changes (see e.g. Oke, T. R. \textit{Street Design and Urban Canopy Layer Climate}. Energy and Buildings, 11 (1988)). 381 \end{frame} 382 383 % Folie 19 384 \begin{frame} 385 \frametitle{Answer to question 2 (I)} 386 \footnotesize 387 \textbf{How do the horizontally and temporally averaged velocity and momentum flux profiles look like?} 388 \par\smallskip 389 \footnotesize 390 Frame 12 shows 1-h and horizontally averaged vertical profiles of velocity components \textit{u}, \textit{v} and \textit{w}: 391 \scriptsize 392 \begin{itemize} 393 \item{\textit{u}: Channel flow causes zero velocity at bottom and top domain wall. Upper domain half: Velocities increase with distance from upper channel wall, peaks at around 60m, and decreases quickly closer towards cube top. Lower domain half: \textit{u} further decreases towards bottom channel wall, due to roughness of the wall, and \textit{u} is much smaller here than in upper domain half, due to presence of cube.} 394 \item{\textit{v}: In the horizontal average, \textit{v}-component is much smaller than \textit{u}, and it fluctuates around zero. Time average should be increased to further eliminate these fluctuations. Flow is forced by \textit{u}-component}, and cube does not induce significant \textit{v} in horizontal mean. 395 \item{\textit{w}: Zero above, small negative values below cube top. In fully developed LES with sufficient domain size and averaging, horizontally averaged \textit{w} profile should be zero.} 396 \end{itemize} 397 \end{frame} 398 399 % Folie 20 400 \begin{frame} 401 \frametitle{Answer to question 2 (II)} 402 \footnotesize 403 \textbf{How do the horizontally and temporally averaged velocity and momentum flux profiles look like?} 404 \par\smallskip 405 \footnotesize 406 Frame 13 shows 1-h and horizontally averaged vertical profiles of \textit{u} and \textit{v} components of total turbulent vertical momentum flux, for two ouput times: 407 \scriptsize 408 \begin{itemize} 409 \item{\textit{wv} is one order of magnitude smaller than \textit{wu} (flow is forced with the \textit{u}-component), hence, the \textit{wv} profile is not smooth, it strongly fluctuates with heigt and time.} 410 \item{In contrast, the \textit{wu} profile is smooth and barely changes from one 1-h average to the next, indicating sufficient averaging time.} 411 \end{itemize} 412 \end{frame} 413 414 % Folie 21 415 \begin{frame} 416 \frametitle{Answer to question 2 (III)} 417 \footnotesize 418 \textbf{How does the horizontally and temporally averaged momentum flux profile look like?} 419 \par\smallskip 420 \scriptsize 421 \begin{itemize} 422 \item{This \textit{wu} profile of channel flow around a cube strongly deviates from the typical \textit{wu profile} in a neutral obstacle-free atmospheric boundary layer (ABL). In the latter, \textit{wu} takes largest negative values at the surface and increases towards zero at the top the boundary layer. This means, the flow is decelerated everywhere within the ABL due to surface friction. In the cube-flow, the \textit{wu} profile can be split into three regions:} 423 \begin{itemize} 424 {\scriptsize 425 \item{z=40 to 80m: linear increase with height, i.e. the flow is decelerated in this part. Up to 65m, \textit{wu} is negative, i.e. the roughness of the cube top causes the deceleration. Above, \textit{wu} is positive, i.e. the flow is decelerated due to the no-slip boundary condition at the domain top.} 426 \item{z=15 to 40m: decreasing with height, i.e. the flow is accelerated here, which can be attributed to the above-cube flow.} 427 \item{z=0 to 15m: increasing with height, meaning flow deceleration, due to surface friction.}} 428 \end{itemize} 429 \end{itemize} 430 \par\bigskip 431 \scriptsize 432 \textbf{Note: Such momentum flux profiles (\textit{wu}) are typical for urban and vegetation canopy flows.} 433 \end{frame} 434 435 436 % Folie 22 437 \begin{frame} 438 \frametitle{Answer to question 3} 439 \footnotesize 440 \textbf{Is it really a fully developed large-eddy simulation?} 441 \par\smallskip 442 \scriptsize 443 \begin{itemize} 444 \item{Frame 14: Except near the surface and at the domain top, subgrid-scale momentum flux \textit{w``u''} is one order of magnitude smaller than the resolved-scale counterpart \textit{w*u*}, hence we can conclude, that the grid spacing is sufficiently small in order to resolve the energy-containing eddies within this neutral flow around a solid cube.} 445 \item{Frame 15: Timeseries of the kinetic energy \textit{E} and the maximum \textit{u} value in the flow indicate that two hours of simulation time are sufficient for the spin up of the model. Both quantities level out towards the end of the simulation.} 446 \item{Frame 16: The temporal evolution of maximum \textit{v} and \textit{w} values indicates that the flow shows turbulent features, since both components frequently change signs.} 447 \end{itemize} 448 \end{frame} 449 304 450 \end{document} -
palm/trunk/TUTORIAL/SOURCE/topography.tex
r1515 r1541 22 22 \usepackage{pdfcomment} 23 23 \usepackage{xcolor} 24 \usepackage{tabto} 24 25 25 26 \institute{Institute of Meteorology and Climatology, Leibniz UniversitÀt Hannover} … … 54 55 \end{frame} 55 56 56 \section{Topography}57 \subsection{Topography}58 57 59 58 % Folie 2 … … 62 61 \begin{itemize} 63 62 \item{Purpose of topography in PALM} 64 \item{Definition}65 63 \item{Realization} 66 64 \begin{itemize} 65 \item{Definition} 67 66 \item{Physical concept} 68 67 \item{Technical / numerical implementation} 69 \end{itemize}70 \ item{Strengths and limitations}68 \item{Strengths and limitations} 69 \end{itemize} 71 70 \item{Control parameters} 72 71 \begin{itemize} … … 81 80 \end{itemize} 82 81 \end{frame} 82 83 \section{Purpose} 84 \subsection{Purpose} 83 85 84 86 % Folie 3 … … 98 100 \end{frame} 99 101 102 \section{Realization} 103 \subsection{Realization} 104 100 105 % Folie 4 101 106 \begin{frame} 102 107 \frametitle{Definition} 103 108 \begin{itemize} 104 \item{T he topography definitionin PALM covers solid, impermeable, fixed flow obstacles with a volume of at least one grid box.}105 \par\bigskip 106 \item{ The following qualifies as topography: \textcolor{green!50!black!100}{\checkmark}}109 \item{Topography in PALM covers solid, impermeable, fixed flow obstacles with a volume of at least one grid box.} 110 \par\bigskip 111 \item{Following qualifies as topography: \textcolor{green!50!black!100}{\checkmark}} 107 112 \begin{itemize} 108 113 \footnotesize 109 \item{ Human-madeobstacles (buildings)}114 \item{Artificial obstacles (buildings)} 110 115 \item{Natural obstacles (hills, mountains)} 111 116 \end{itemize} … … 117 122 \> canopy model, local roughness length \end{tabbing} } 118 123 \item{Small obstacles (signposts)} 119 \item{Moving obstacles (vehicles )}124 \item{Moving obstacles (vehicles, wind turbine rotors)} 120 125 \end{itemize} 121 126 \end{itemize} … … 134 139 \end{columns} 135 140 \begin{columns}[c] 136 \column{0. 6\textwidth}141 \column{0.4\textwidth} 137 142 \begin{itemize} 138 143 \item{Grid boxes are} 139 144 \begin{itemize} 140 \item{\begin{minipage}{0.1\textwidth} 141 \includegraphics[width=0.7\textwidth]{topography_figures/physical_concept_small1.png} 142 \end{minipage} 143 \begin{minipage}{0.5\textwidth} \scriptsize 145 \item{\begin{minipage}{0.4\textwidth} \scriptsize 144 146 \par\medskip 145 100\% free fluid, \\147 100\% \\free fluid, \\ 146 148 \end{minipage}} 147 \item{\begin{minipage}{0.1\textwidth} 148 \includegraphics[width=0.7\textwidth]{topography_figures/physical_concept_small2.png} 149 \end{minipage} 150 \begin{minipage}{0.5\textwidth} \scriptsize 151 100\% fluid adjacent to an obstacle, or 149 \item{\begin{minipage}{0.4\textwidth} \scriptsize 150 100\% \\fluid adjacent to an obstacle, or 152 151 \end{minipage}} 153 \item{\begin{minipage}{0.1\textwidth} 154 \includegraphics[width=0.7\textwidth]{topography_figures/physical_concept_small3.png} 155 \end{minipage} 156 \begin{minipage}{0.5\textwidth} \scriptsize 152 \item{\begin{minipage}{0.4\textwidth} \scriptsize 157 153 \par\medskip 158 154 100\% obstacle. \\ 159 155 \end{minipage}} 160 156 \end{itemize} 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} 161 164 \item{No-slip boundary condition} 162 165 \begin{itemize} 163 \item{\scriptsize Wall-normal velocity component is zero at obstacle surface \textbf{\textcolor{blue}{---------}}}166 \item{\scriptsize Wall-normal velocity component is zero at obstacle surface} 164 167 \end{itemize} 165 168 \par\bigskip 166 \item{\begin{minipage}{0. 75\textwidth} \scriptsize167 Local surface layer for the first grid box \\adjacent to each obstacle surface169 \item{\begin{minipage}{0.8\textwidth} \scriptsize 170 Local surface layer for the first grid box adjacent to each obstacle surface 168 171 \end{minipage} 169 172 \begin{minipage}{0.1\textwidth} 170 \includegraphics[width=0. 7\textwidth]{topography_figures/physical_concept_small2.png}173 \includegraphics[width=0.35\textwidth]{topography_figures/physical_concept_small.eps} 171 174 \end{minipage}} 172 175 \par\smallskip … … 175 178 \end{itemize} 176 179 \end{itemize} 177 \column{0.4\textwidth}178 \includegraphics[width=\textwidth]{topography_figures/physical_concept.png}179 180 \end{columns} 180 181 \end{frame} … … 183 184 \begin{frame} 184 185 \frametitle{Realization - \\ Numerical /Technical Implementation (I)} 186 \small 187 \begin{columns}[c] 188 \column{0.65\textwidth} 189 \begin{itemize} 190 \item{Obstacles must be surface-mounted} 191 \item{Overhanging structures \textbf{\textcolor{blue}{$\times$}}, holes \textbf{\textcolor{red}{$\times$}} etc. are not permitted.} 192 \begin{itemize} 193 \footnotesize 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).} 196 \item{This conforms to the "'2.5D"' format of Digital Elevation Models (DEM).} 197 \end{itemize} 198 \end{itemize} 199 \column{0.3\textwidth} 200 \par\medskip 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} 205 \end{columns} 206 \end{frame} 207 208 % Folie 7 209 \begin{frame} 210 \frametitle{Realization - \\ Numerical /Technical Implementation (II)} 185 211 \small 186 212 \begin{columns}[c] 187 213 \column{0.5\textwidth} 188 214 \begin{itemize} 189 \item{Obstacles must be surface-mounted} 190 \item{Overhanging structures \textcolor{blue}{$\times$}, holes \textcolor{red}{$\times$} etc. are not permitted.} 191 \begin{itemize} 192 \footnotesize 193 \item{This simplification allows extra performance optimization by reducing the 3D obstacle dimension to a "'2.5D"' dimension.} 194 \item{"'2.5D"' means that each horizontal grid cell is assigned only one height level.} 195 \item{This conforms to the "'2.5D"' format of Digital Elevation Models (DEM).} 196 \end{itemize} 197 \end{itemize} 198 \column{0.4\textwidth} 199 \par\medskip 200 \includegraphics[width=1.1\textwidth]{topography_figures/technical_implementation.png} 201 \end{columns} 202 \end{frame} 203 204 % Folie 7 205 \begin{frame} 206 \frametitle{Realization - \\ Numerical /Technical Implementation (II)} 207 \begin{columns}[c] 208 \column{0.4\textwidth} 209 \footnotesize 210 The location of the wall-normal velocity component defines the location of the impermeable obstacle surface. \\ 211 \par\smallskip 212 Obstacle surfaces that do not match the grid are approximated by grid boxes like a step-function. 213 \par\bigskip 214 $\bullet$ scalars \\ 215 \textcolor{red}{$\bullet$ u (staggered)} \\ 216 \textcolor{green!40!black!100}{\textbf{+} v (staggered)} 217 % \includegraphics[width=0.4\textwidth]{topography_figures/technical_implementation_grid/technical_implementation_grid_small1.png} \\ 218 % \includegraphics[width=0.6\textwidth]{topography_figures/technical_implementation_grid/technical_implementation_grid_small2.png} \\ 219 % \includegraphics[width=0.6\textwidth]{topography_figures/technical_implementation_grid/technical_implementation_grid_small3.png} 220 \column{0.6\textwidth} 221 \includegraphics<1|handout:0>[width=\textwidth]{topography_figures/technical_implementation_grid/technical_implementation_grid_1.png} 222 \includegraphics<2|handout:0>[width=\textwidth]{topography_figures/technical_implementation_grid/technical_implementation_grid_2.png} 223 \includegraphics<3|handout:0>[width=\textwidth]{topography_figures/technical_implementation_grid/technical_implementation_grid_3.png} 224 \includegraphics<4|handout:0>[width=\textwidth]{topography_figures/technical_implementation_grid/technical_implementation_grid_4.png} 225 \includegraphics<5|handout:1>[width=\textwidth]{topography_figures/technical_implementation_grid/technical_implementation_grid_5.png} 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} 218 \par\bigskip 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} 226 224 \end{columns} 227 225 \end{frame} … … 234 232 \begin{itemize} 235 233 \item{In order to process topography from external data sources, the data must be made available 236 to PALM as a rastered ASCII file, e.g. example\_topo.} 237 \item{The layout of example\_topo must conform to the computational domain size and to the grid size dx and dy.} 238 \item{The rastered height data of example\_topo are given in m above ground and do not need to match 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 239 240 the vertical grid, since they will be interpolated, if required.} 240 241 \par\bigskip … … 251 252 \frametitle{Realization â \\ Numerical / Technical Implementation (IV)} 252 253 \small 253 \textbf{Potential issue} 254 \begin{itemize} 255 \item{Load imbalance} 256 \begin{itemize} 257 \item{Leads to inefficient parallelization: \dq fast\dq CPU(s) must wait for \dq slow\dq CPU(s)} 258 \item{Occurs if the CPUs do not share the same workload} 259 \begin{itemize} 260 \item{E.g. if topography is significantly heterogeneous in a large volume fraction of the computational domain} 261 \end{itemize} 262 \end{itemize} 263 \end{itemize} 254 \textbf{Potential issue: Load imbalance} 255 \begin{columns}[c] 256 \column{0.55\textwidth} 257 \begin{itemize} 258 \item{Since prognostic equations are not calculated inside buildings, \\ \textbf{load imbalance} might occur, if topography is heterogeneously distributed among the subdomains.} 259 \begin{itemize} 260 \item{This means \dq fast\dq CPU(s) must wait for \dq slow\dq CPU(s), leading to inefficient parallelization.} 261 \end{itemize} 262 \end{itemize} 263 \column{0.45\textwidth} 264 \includegraphics[angle=90,width=\textwidth]{topography_figures/load_imbalance.eps} 265 \end{columns} 264 266 \end{frame} 265 267 … … 273 275 \item[+]{Conforms with \dq 2.5D\dq format of Digital Elevation Models (DEM)} 274 276 \par\bigskip 275 \item[ -]{Obstacles must be surface-mounted}276 \item[ -]{Grid boxes can only be 100\% fluid or 100\% obstacle \\ \par\smallskip277 \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}}278 \item[-]{Overhanging structures, holes etc. are not permitted due to the \dq 2.5D\dq format}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}} 279 281 \end{itemize} 280 282 \end{frame} … … 284 286 \frametitle{Take a Short Break... Urban Flow Visualization} 285 287 \begin{columns}[c] 286 \column{0.42\textwidth} 287 \includegraphics<1>[width=\textwidth]{topography_figures/hannover_1.png} 288 \href{.html}{\includegraphics<2>[width=\textwidth]{topography_figures/hannover_2.png}} 289 \column{0.58\textwidth} 290 Set-up: neutral boundary layer 291 \begin{itemize} 292 \item{Particle = passive tracer} 293 \item{Colour $\sim$ particle height} 294 \item{Tail length ~ particle velocity} 295 \end{itemize} 296 \par\bigskip 297 \begin{itemize} 298 \item{Flow past office tower:} 299 \begin{itemize} 300 \item{initially laminar: not yet an LES} 301 \item{intermittent: different episodes} 302 \end{itemize} 303 \item{Broad street canyon flow:} 304 \begin{itemize} 305 \item{channeling} 306 \item{low-level upstream flow} 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} 296 \begin{itemize} 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} 301 \begin{itemize} 302 \uncover<2>{\item{Flow past office tower:}} 303 \begin{itemize} 304 \uncover<2>{\item{initially laminar: not yet an LES}} 305 \uncover<2>{\item{intermittent: different episodes}} 306 \end{itemize} 307 \uncover<2>{\item{Broad street canyon flow:}} 308 \begin{itemize} 309 \uncover<2>{\item{channeling}} 310 \uncover<2>{\item{low-level upstream flow}} 307 311 \end{itemize} 308 312 \end{itemize} … … 310 314 \end{frame} 311 315 316 \section{Control parameters} 317 \subsection{Control parameters} 318 312 319 % Folie 12 313 320 \begin{frame} 314 321 \frametitle{Required Topography Control Parameters} 315 \footnotesize 316 {\tt topography =} 317 \begin{itemize} 318 \item{{\tt 'flat'} \hspace{3cm} no topography (default)} 319 \item{{\tt 'single\_building'} \hspace{1.2cm} \textcolor{red}{generic} single building} 320 \item{{\tt 'single\_street\_canyon'} \hspace{0.4cm} \textcolor{red}{generic} single quasi-2D street canyon} 321 \item{{\tt 'read\_from\_file'} \hspace{1.4cm} \textcolor{blue}{rastered} ASCII file, e.g. {\tt example\_topo}} 322 \item{any other string \hspace{1.8cm} processed by user subroutine user\_init\_grid} 323 \end{itemize} 324 {\tt topography\_grid\_convention =} 325 \begin{itemize} 326 \item{{\tt '\textcolor{red}{cell\_edge}'} \hspace{2.2cm} default for \textcolor{red}{generic} topography: \textcolor{red}{$\leftrightarrow$}} 327 \item{{\tt '\textcolor{blue}{cell\_center}'} \hspace{1.9cm} default for \textcolor{blue}{rastered} topography: \textcolor{blue}{$\bigcirc$ $\leftrightarrow$}} 328 \end{itemize} 329 \includegraphics<1|handout:0>[width=0.5\textwidth]{topography_figures/control_parameters_1.png} 330 \includegraphics<2|handout:0>[width=0.5\textwidth]{topography_figures/control_parameters_2.png} 331 \includegraphics<3|handout:0>[width=0.5\textwidth]{topography_figures/control_parameters_3.png} 332 \includegraphics<4|handout:1>[width=0.5\textwidth]{topography_figures/control_parameters_4.png} 322 \scriptsize 323 \uncover<1->{{\tt topography =}} 324 \begin{itemize} 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}} 330 \end{itemize} 331 \uncover<2->{{\tt topography\_grid\_convention =}} 332 \begin{itemize} 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}{$\bigcirc$ $\leftrightarrow$}}} 335 \end{itemize} 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} 333 338 \end{frame} 334 339 … … 337 342 \frametitle{Optional Topography Control Parameters (I)} 338 343 \small 339 \textbf{Generic topography} 340 \scriptsize 341 \begin{itemize} 342 \item{topography = {\tt 'single\_building'}} 343 \begin{itemize} 344 \scriptsize 345 \item{building\_height = 50.0 \hspace{0.67cm} height of the building} 346 \item{building\_length\_x = 50.0 \hspace{0.43cm} length of the building in x-direction} 347 \item{building\_length\_y = 50.0 \hspace{0.43cm} length of the building in y-direction} 348 \item{building\_wall\_left \hspace{1.4cm} (default is building centered in x-direction)} 349 \item{building\_wall\_south \hspace{1.13cm} (default is building centered in y-direction)} 350 \end{itemize} 351 \item{topography = {\tt 'single\_street\_canyon'}} 352 \begin{itemize} 353 \scriptsize 354 \item{canyon\_height = 50.0 \hspace{0.45cm} height of the canyon \\ 355 and} 356 \item{canyon\_width\_x = 50.0 \hspace{0.3cm} implies canyon axis orientation in y-direction} 357 \item{canyon\_wall\_left \hspace{1.17cm} (default is canyon centered in x-direction) \\ 358 or} 359 \item{canyon\_width\_y = 50.0 \hspace{0.3cm} implies canyon axis orientation in x-direction} 360 \item{canyon\_wall\_south \hspace{0.9cm} (default is canyon centered in y-direction)} 361 \end{itemize} 362 \end{itemize} 344 \textbf{Generic topography} 345 \begin{figure} 346 \centering\includegraphics[width=.8\textwidth]{topography_figures/single_building_parameters.eps} 347 \end{figure} 363 348 \end{frame} 364 349 … … 366 351 \begin{frame} 367 352 \frametitle{Optional Topography Control Parameters (II)} 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)} 368 363 \scriptsize 369 364 \textbf{Rastered topography}\\ 370 \begin{minipage}{0. 7\textwidth}365 \begin{minipage}{0.8\textwidth} 371 366 \begin{itemize} 372 367 \scriptsize … … 378 373 \end{itemize} 379 374 \end{minipage} 380 \begin{minipage}{0. 2\textwidth}375 \begin{minipage}{0.15\textwidth} 381 376 \includegraphics[width=0.5\textwidth]{topography_figures/optional_control_parameters_1.png} 382 377 \end{minipage} 383 378 \begin{center} 384 \includegraphics[width=0. 85\textwidth]{topography_figures/optional_control_parameters_2.png}379 \includegraphics[width=0.75\textwidth]{topography_figures/optional_control_parameters_2.png} 385 380 \end{center} 386 381 \begin{itemize} 387 382 \item[]{} 388 383 \begin{itemize} 389 \scriptsize 390 \item{layout must conform to domain size and grid size dx and dy.} 391 \item{height data} 392 \begin{itemize} 393 \scriptsize 394 \item{in m above ground (INTEGER or REAL)} 395 \item{do not need to match the vertical grid} 396 \end{itemize} 397 \end{itemize} 398 \end{itemize} 399 \end{frame} 400 401 % Folie 15 402 \begin{frame} 403 \frametitle{Optional Topography Control Parameters (III)} 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} 388 \end{itemize} 389 \end{itemize} 390 \end{frame} 391 392 % Folie 16 393 \begin{frame} 394 \frametitle{Optional Topography Control Parameters (IV)} 404 395 \small 405 396 \textbf{Rastered topography} … … 417 408 \end{frame} 418 409 419 % Folie 1 6410 % Folie 17 420 411 \begin{frame} 421 412 \frametitle{General Control Parameters (I): Suitable Driving Methods} … … 460 451 \end{frame} 461 452 462 % Folie 1 7453 % Folie 18 463 454 \begin{frame} 464 455 \frametitle{General Control Parameters (II): Initialization} … … 500 491 \end{frame} 501 492 502 % Folie 1 8493 % Folie 19 503 494 \begin{frame} 504 495 \frametitle{General Control Parameters (III): Boundary Conditions} … … 524 515 \end{frame} 525 516 526 % Folie 19517 % Folie 20 527 518 \begin{frame} 528 519 \frametitle{General Control Parameters (IV): Pressure Solver} … … 544 535 \end{frame} 545 536 546 % Folie 20 537 \section{Data output/ Scenarios} 538 \subsection{Data output/ Scenarios} 539 540 % Folie 21 547 541 \begin{frame} 548 542 \frametitle{Data Analysis / Output â Some Considerations (I)} … … 580 574 \end{frame} 581 575 582 % Folie 2 1576 % Folie 22 583 577 \begin{frame} 584 578 \frametitle{Your Responsibility and Contribution} … … 598 592 \end{frame} 599 593 600 % Folie 2 2594 % Folie 23 601 595 \begin{frame} 602 596 \frametitle{Some recent examples of topography/building applications with PALM} … … 645 639 \end{frame} 646 640 647 % Folie 2 2641 % Folie 24 648 642 \begin{frame} 649 643 \Large … … 651 645 \end{frame} 652 646 653 % Folie 2 3647 % Folie 25 654 648 \begin{frame} 655 649 \frametitle{Set-up Scenario: Single Street Canyon (I)} … … 670 664 \end{frame} 671 665 672 % Folie 2 4666 % Folie 26 673 667 \begin{frame} 674 668 \frametitle{Set-up Scenario: Single Street Canyon (II)} … … 680 674 \end{frame} 681 675 682 % Folie 2 5676 % Folie 27 683 677 \begin{frame} 684 678 \begin{tikzpicture}[remember picture, overlay] … … 686 680 {% 687 681 \begin{tikzpicture}[remember picture, overlay] 688 \uncover<1>{\node at (0,-0.5) {\includegraphics[width=0.7\textwidth]{topography_figures/scenario_ssc_example_1.png}};} 689 \uncover<2->{\node at (0,-0.5) {\includegraphics[width=0.7\textwidth]{topography_figures/scenario_ssc_example_2.png}};} 690 %\uncover<3->{\node at (0,-0.5) {\includegraphics[width=0.7\textwidth]{topography_figures/scenario_ssc_example_3.png}};} 691 \uncover<3->{\node at (-3.5,-0.2) {\includegraphics[width=0.48\textwidth]{topography_figures/scenario_ssc_example_4.png}};} 692 \uncover<4->{\node at (3.5,-0.2) {\includegraphics[width=0.38\textwidth]{topography_figures/scenario_ssc_example_5.png}};} 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}};} 693 684 \end{tikzpicture} 694 685 }; … … 696 687 \end{frame} 697 688 698 % Folie 26 689 % Folie 28 690 \begin{frame} 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 29 699 705 \begin{frame} 700 706 \frametitle{Set-up Scenario: Constant Flux Layer} … … 715 721 \end{frame} 716 722 717 % Folie 27723 % Folie 30 718 724 \begin{frame} 719 725 \begin{tikzpicture}[remember picture, overlay] … … 722 728 \begin{tikzpicture}[remember picture, overlay] 723 729 \uncover<1->{\node at (0,-0.5) {\includegraphics[width=0.7\textwidth]{topography_figures/scenario_cfl_example_1.png}};} 724 \uncover<2->{\node at (-3.5,-0.2) {\includegraphics[width=0.45\textwidth]{topography_figures/scenario_cfl_example_2.png}};}725 \uncover<3->{\node at (3.5,-0.2) {\includegraphics[width=0.38\textwidth]{topography_figures/scenario_cfl_example_3.png}};}726 730 \end{tikzpicture} 727 731 }; … … 729 733 \end{frame} 730 734 731 % Folie 28 735 % 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}};} 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} 748 749 % Folie 32 732 750 \begin{frame} 733 751 \frametitle{Rules of Good Practise}
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