% $Id: exercise_cbl.tex 954 2012-07-20 07:44:19Z letzel $ \input{header_tmp.tex} %\input{../header_lectures.tex} \usepackage[utf8]{inputenc} \usepackage{ngerman} \usepackage{pgf} \usetheme{Dresden} \usepackage{subfigure} \usepackage{units} \usepackage{multimedia} \usepackage{hyperref} \newcommand{\event}[1]{\newcommand{\eventname}{#1}} \usepackage{xmpmulti} \usepackage{tikz} \usetikzlibrary{shapes,arrows,positioning} \usetikzlibrary{decorations.markings} %neues paket \usetikzlibrary{decorations.pathreplacing} %neues paket \def\Tiny{\fontsize{4pt}{4pt}\selectfont} \usepackage{amsmath} \usepackage{amssymb} \usepackage{multicol} \usepackage{pdfcomment} \usepackage{graphicx} \usepackage{listings} \lstset{showspaces=false,language=fortran,basicstyle= \ttfamily,showstringspaces=false,captionpos=b} \institute{Institut für Meteorologie und Klimatologie, Leibniz Universität Hannover} \date{last update: \today} \event{PALM Seminar} \setbeamertemplate{navigation symbols}{} \setbeamertemplate{footline} { \begin{beamercolorbox}[rightskip=-0.1cm]& {\includegraphics[height=0.65cm]{imuk_logo.pdf}\hfill \includegraphics[height=0.65cm]{luh_logo.pdf}} \end{beamercolorbox} \begin{beamercolorbox}[ht=2.5ex,dp=1.125ex, leftskip=.3cm,rightskip=0.3cm plus1fil]{title in head/foot} {\leavevmode{\usebeamerfont{author in head/foot}\insertshortauthor} \hfill \eventname \hfill \insertframenumber \; / \inserttotalframenumber} \end{beamercolorbox} \begin{beamercolorbox}[colsep=1.5pt]{lower separation line foot} \end{beamercolorbox} } %\logo{\includegraphics[width=0.3\textwidth]{luhimuk_logo.pdf}} \title[Exercise 1: Convection Between Plates]{Exercise 1: Convection Between Plates} \author{Siegfried Raasch} \begin{document} % Folie 1 \begin{frame} \titlepage \end{frame} \section{Exercise} \subsection{Exercise} % Folie 2 \begin{frame} \frametitle{Exercise 1: Convection Between Plates} Please try to carry out a run with following initial and boundary conditions and create the required output. \begin{itemize} \scriptsize \item<2-> The simulation should represent a stationary convective boundary layer between two uniformly heated/cooled plates with zero mean flow. \item<3-> A free-slip condition for velocity shall be used at the bottom and top boundary. \item<4-> The sensible heat flux at the bottom and top boundary shall be constant throughout the simulation. \end{itemize} \onslide<5-> Simulation features: \begin{itemize} \scriptsize \item<6-> domain size: about $\unit[2000 \times 2000 \times 1000]{m}$ ($x$/$y$/$z$) \item<7-> grid size: $\unit[50]{m}$ equidistant \item<8-> simulated time: $\unit[3600]{s}$ \item<9-> surface heatflux: $\unit[0.1]{K\ m\ s^{-1}}$ \item<10-> heatflux at top: $\unit[0.1]{K\ m\ s^{-1}}$ \item<11-> initial temperature: $\unit[300]{K}$ everywhere \item<12-> initial velocity: zero, everywhere \end{itemize} \end{frame} % Folie 3 \begin{frame} \frametitle{Questions to be Answered:} \begin{itemize} \item<1-> How does the flow field looks like after 60 minutes simulated time? (what kind of output do you need to answer this?) \item<2-> How do the horizontally and temporally averaged vertical temperature and heat flux profile look like? \item<3-> Is it really a large-eddy simulation, i.e. are the subgrid-scale fluxes much smaller than the resolved-scale fluxes? (How long should the averaging time interval be?) \item<4-> How do the total kinetic energy and the maximum velocity components change in time? Has the flow become stationary? \item<5-> Has the domain size and grid size been chosen appropriately? \end{itemize} \end{frame} % Folie 4 \begin{frame} \frametitle{Hints (I)} \scriptsize PALM parameter names are displayed by courier style, e.g. \textcolor{blue}{\texttt{end\_time}}.\\ \begin{itemize} \item<2-> Domain size \begin{itemize} \scriptsize \item[-]<2-> Is controled by grid size (\textcolor{blue}{\texttt{dx}}, \textcolor{blue}{\texttt{dy}}, \textcolor{blue}{\texttt{dz}}) and number of grid points (\textcolor{blue}{\texttt{nx}}, \textcolor{blue}{\texttt{ny}}, \textcolor{blue}{\texttt{nz}}). Since the first grid point along one of the directions has index 0, the total number of grid points used are \textcolor{blue}{\texttt{nx}}+1, \textcolor{blue}{\texttt{ny}}+1, \textcolor{blue}{\texttt{nz}}+1. The total domain size in case of cyclic horizontal boundary conditions is (\textcolor{blue}{\texttt{nx}}+1)*\textcolor{blue}{\texttt{dx}}, (\textcolor{blue}{\texttt{ny}}+1)*\textcolor{blue}{\texttt{dy}}. \end{itemize} \item<3-> Initial profiles \begin{itemize} \scriptsize \item[-]<3-> Constant with height. See parameter \textcolor{blue}{\texttt{initializing\_actions}} for available initialization methods. See \textcolor{blue}{\texttt{ug\_surface}}, \textcolor{blue}{\texttt{vg\_surface}} and \textcolor{blue}{\texttt{pt\_surface}} for initial values of velocity and potential temperature. \end{itemize} \item<4-> Boundary conditions \begin{itemize} \scriptsize \item[-]<4-> For velocity, see \textcolor{blue}{\texttt{bc\_uv\_b}} and \textcolor{blue}{\texttt{bc\_uv\_t}}. See also \textcolor{blue}{\texttt{prandtl\_layer}}, because Neumann conditions don’t allow to use a Prandtl-layer. \item[-]<5-> For temperature / heat flux, see \textcolor{blue}{\texttt{surface\_heatflux}} and \textcolor{blue}{\texttt{top\_heatflux}}. Prescribing of heat flux at the boundary requires a Neumann boundary condition for temperature, see \textcolor{blue}{\texttt{bc\_pt\_b}} and \textcolor{blue}{\texttt{bc\_pt\_t}}. \item[-]<6-> Use a Neumann condition also for the perturbation pressure both at the bottom and the top (\textcolor{blue}{\texttt{bc\_p\_b}}, \textcolor{blue}{\texttt{bc\_p\_t}}). \end{itemize} \item<7-> Simulation time \begin{itemize} \scriptsize \item[-]<7-> See parameter \textcolor{blue}{\texttt{end\_time}}. \end{itemize} \end{itemize} \end{frame} % Folie 5 \begin{frame} \frametitle{Hints (II)} \footnotesize Hints for data output. \begin{itemize} \item<2-> Variables \begin{itemize} \footnotesize \item[-]<2-> Output variables are chosen with parameters \textcolor{blue}{\texttt{data\_output}} (3d-data or 2d-cross-sections) and \textcolor{blue}{\texttt{data\_output\_pr}} (profiles). \end{itemize} \item<3-> Output intervals \begin{itemize} \footnotesize \item[-]<3-> Output intervals are set with parameter \textcolor{blue}{\texttt{dt\_data\_output}}. This parameter affects all output (cross-sections, profiles, etc.). Individual temporal intervals for the different output quantities can be assigned using parameters \textcolor{blue}{\texttt{dt\_do3d}}, \textcolor{blue}{\texttt{dt\_do2d\_xy}}, \textcolor{blue}{\texttt{dt\_do2d\_xz}}, \textcolor{blue}{\texttt{dt\_do2d\_yz}}, \textcolor{blue}{\texttt{dt\_dopr}}, etc. \end{itemize} \item<4-> Time averaging \begin{itemize} \footnotesize \item[-]<4-> Time averaging is controlled with parameters \textcolor{blue}{\texttt{averaging\_interval}}, \textcolor{blue}{\texttt{averaging\_interval\_pr}}, \textcolor{blue}{\texttt{dt\_averaging\_input}}, \textcolor{blue}{\texttt{dt\_averaging\_input\_pr}}. \end{itemize} \end{itemize} \end{frame} % Folie 6 \begin{frame} \frametitle{Further Hints} \onslide<2-> You will find some more detailed information to solve this exercise in the PALM-online-documentation under (attention: the documentation is for atmospheric convection with free upper lid):\\ \ \\ \small\url{http://palm.muk.uni-hannover.de/wiki/doc/app/examples/cbl}\\ \ \\ \ \\ \normalsize Please also see under\\ \ \\ \small\url{http://palm.muk.uni-hannover.de/wiki/doc/app/netcdf}\\ \ \\ \normalsize where the complete PALM netCDF-data-output and the respective steering parameters are described. \end{frame} % Folie 7 \begin{frame} \frametitle{How to Start?} \begin{itemize} \item<2-> Create a data directory for a new run:\\ \quad \texttt{cd \~{}/palm/current\_version}\\ \quad \texttt{mkdir -p JOBS/uniform\_plates/INPUT} \item<3-> Create the parameter file and set the required parameters in\\ \quad \texttt{JOBS/uniform\_plates/INPUT/uniform\_plates\_p3d} \item<4-> Start the run with \texttt{mrun-command}\\ \quad \texttt{mrun -d uniform\_plates -h -K parallel ...}\\ and analyze the output files. \end{itemize} \ \\ \onslide<5-> \huge \centering \textcolor{blue}{Good Luck!} \end{frame} % Folie 8 \section{Results} \subsection{Results} \begin{frame} \frametitle{$xy$-cross sections (instantaneous)} \begin{center} \includegraphics[width=0.42\textwidth]{exercise_cbl_figures/xy_w_100.eps} \includegraphics[width=0.42\textwidth]{exercise_cbl_figures/xy_w_500.eps}\\ \includegraphics[width=0.42\textwidth]{exercise_cbl_figures/xy_w_750.eps} \end{center} \end{frame} % Folie 9 \begin{frame} \frametitle{$xz$-cross sections ($\unit[900]{s}$ average)} \begin{center} \includegraphics[width=0.55\textwidth]{exercise_cbl_figures/xz_w_y250m.eps} \includegraphics[width=0.55\textwidth]{exercise_cbl_figures/xz_w_y500m.eps}\\ \includegraphics[width=0.55\textwidth]{exercise_cbl_figures/xz_w_y750m.eps} \includegraphics[width=0.55\textwidth]{exercise_cbl_figures/xz_w_y1000m.eps} \end{center} \end{frame} % Folie 10 \begin{frame} \frametitle{Vertical profiles (I)} \begin{center} \includegraphics[width=0.55\textwidth]{exercise_cbl_figures/pr_pt.eps} \includegraphics[width=0.55\textwidth]{exercise_cbl_figures/pr_wpt.eps} \end{center} \end{frame} % Folie 11 \begin{frame} \frametitle{LES?} \begin{center} \includegraphics[width=0.55\textwidth]{exercise_cbl_figures/pr_wpt2.eps} \includegraphics[width=0.55\textwidth]{exercise_cbl_figures/pr_wpt_resolved.eps} \end{center} \end{frame} % Folie 12 \begin{frame} \frametitle{Time series (I)} \begin{center} \includegraphics[width=1.0\textwidth]{exercise_cbl_figures/ts.eps} \end{center} \end{frame} % Folie 13 \begin{frame} \frametitle{Time series (II)} \begin{center} \includegraphics[width=1.0\textwidth]{exercise_cbl_figures/ts2.eps} \end{center} \end{frame} \end{document}