?? readme.htm
字號:
<html><head><title>README for 'anb'</title></head><body bgcolor=#ffffff><center><h2>README for the free lattice Boltzmann code 'anb'</h2></center><p><center><em>-- Draft Version (2001-03-29) -- <BR><a href="http://www.ccrl-nece.de/bernsdorf/">Jörg BERNSDORF</a>,<a href="http://www.ccrl-nece.de/">C&C Research Laboratories</a>, NECEurope Ltd.<BR> D-53757 Sankt Augustin / Germany </em></center><P><center><em>Please send any questions/comments to<a href="mailto:bernsdorf@ccrl-nece.de">bernsdorf@ccrl-nece.de</a></center></em><h3>The Purpose</h3>Starting with lattice gas/Boltzmann in 1992, I found it really hard towrite a working code from the scratch only by the help of somepapers. Now, years later, I find it really hard to show newcomers toour group the principles of lattice Boltzmann coding by the help ofour large and complicated code <strong>BEST</strong>, which has been optimized forvector-parallel computers.<p>This is the reason, why I have written a rhichly documented selfexplaining lattice Boltzmann code, where I tried to make everything asclear and simple as possible. The code is called <strong>anb</strong>,what simply means <strong>a</strong>nb is <strong>n</strong>ot<strong>b</strong>est.<p>I hope, <strong>anb</strong> could be used for learning andteaching. It could and should not be used for 'real' computations,esp. not for time- and memory consuming runs on big (and expensive)machines ! Nearly every routine in <strong>anb</strong> could be codedmore efficient, less memory consuming... and less clear.<p>The source code for 'anb' is distributed under the terms of the <ahref="http://www.gnu.org/copyleft/gpl.html">GNU General PublicLicense</a>. <h3>The Code</h3><strong>anb</strong> is written is FORTRAN 77, and has been tested onvarious platforms (SUN, HP, SGI, Linux-PC, Fujitsu VPP, Cray T-90, NECSX 4/5). It contains of the source code itself <tt>anb.f</tt>, oneconfiguration file <tt>anb.par</tt> and one obstacle file <tt>anb.obs</tt>, whichrepresents the geometry information of the flow domain.<a href="anb.f"> You can have a look at the source here !</a><h3>The Usage</h3>Of course, you can just type <tt>f77 anb.f</tt> (or what ever theFORTRAN 77 compiler is called on your system ...) and then run theexecutable. You will see some messages written to stdout and - inthe end - find some new files on your hard disk which are the resultsof the computation. If you have some visualization tool forpost processing (like TECPLOT, for this you can get a temporarily freelicense at <ahref="http://www.genias.de/">http://www.genias.de/</a>) you can have a look at the flow you justsimulated by the help of <strong>anb</strong>. Maybe you should dothis, to see if everything works ...<p>But then, you should do, what the code has been written for:<strong>read and try to understand <a href="anb.f"> the source ofanb.f </a></strong><h3>The anb-package</h3>The package contains:<ul> <li><strong><a href="anb.f">anb.f</a>:</strong> The source code in FORTRAN 77. <li><strong><a href="anb.par">anb.par</a>:</strong> The configuration file for <strong>anb</strong>. <li><strong><a href="anb.obs">anb.obs</a>:</strong> The geometry information file. <li><strong>readme.htm</strong> This text. <li><strong><a Href="COPYING">COPYING</a>:</strong> The <a href="http://www.gnu.org/copyleft/gpl.html">GNU General Public License</a>.</ul>You can donload a "tar.gz" -version of all these files here:<a href="http://www.ccrl-nece.de/lba/anb.tar.gz">http://www.ccrl-nece.de/lba/anb.tar.gz</a><h4>The configuration files</h4><ul> <li><strong>anb.par:</strong> The configuration file for <strong>anb</strong>.<p> Example:<p> <tt> 3000<br> 0.1<br> 0.005<br> 1.85<br> 10<p></tt> Meaning:<p> 1. line: 3000 - number of iterations<br> 2. line: 0.1 - density per link<br> 3. line: 0.005 - acceleration<br> 4. line: 1.85 - relaxation parameter<br> 5. line: 10 - dimension for Reynolds number<p> Have a look at the subroutine <tt>read_parameters</tt> in <tt>anb.f</tt> for more details !<p> <li> <strong>anb.obs:</strong> The geometry information file for <strong>anb</strong>.<p> Example:<p><tt> 1 1<br> 2 1<br> 3 1<p></tt> Meaning:<p> x- and y-coordinates of occupied nodes are listed here, one line for each node. The order does not matter. Also the wall boundary nodes have to be defined in this way !<p> Have a look at the subroutine <tt>read_obstacles</tt> in <tt>anb.f</tt> for more details ! </ul><h4>The result files</h4><ul> <li> <strong>anb_qx.out:</strong> The average velocity of the simulated flow.<p> A good control if the simulated flow reached steady state is to monitor the average flow velocity at a certain cross section of the computational domain as function of time (iterations). You can watch this file for example with the <a href="http://plasma-gate.weizmann.ac.il/Xmgr/">free software xmgr</a>.<p> Example output:<p><tt> 26 1.7849222047450D-04 <br> 27 2.4511573992305D-04 <br> 28 3.1222702284171D-04 <br> ... <br> 2999 3.2984900438651D-03<br> 3000 3.2985335497016D-03<br> 3001 3.2985335497016D-03 <p></tt> Meaning:<p> The column is the iteration number, the second one the computed flow velocity.<p> <li><strong>anb.dat:</strong> The results of the computation. Here, the velocity components, the local pressure and the obstacle information are stored. A header for the post processing tool TECPLOT is also written. If you have some other post processing tool, you should change the necessary things in anb's subroutine datout. Otherwise, it might be a good idea to get a free evaluation license for TECPLOT.<p> Example output:<p><tt> VARIABLES = X, Y, VX, VY, PRESS, OBST<br> ZONE I= 30, J= 20, F=POINT<br> 1 1 0. 0. 3.3333333333333D-02 1<br> 2 1 0. 0. 3.3333333333333D-02 1<br> 3 1 0. 0. 3.3333333333333D-02 1<br> 4 1 0. 0. 3.3333333333333D-02 1<br> ... <br> 4 11 3.2778327874759D-03 2.4387587283551D-04 3.3355060665745D-02 0<br> 5 11 2.7312371998704D-03 3.1218767491485D-04 3.3355269776544D-02 0<br> 6 11 2.0203030622604D-03 3.6169210828650D-04 3.3357471944278D-02 0<br> ... <p></tt> Meaning:<p> Each line in the file anb.dat stands for one lattice node. The x- and y-coordinate of the node is stored in the first two columns, followed by the x- and y-component of the velocity, the local pressure and the information, if the considered node is occupied by an obstacle (1) or a fluid node (0). </ul> <hr> <font size="-1"> Copyright © 1998-2001, Jörg BERNSDORF / C&C Research Laboratories, NEC Europe Ltd. All rights reserved</font> </body> </html>?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -