# Generating a parabolic Profile with groovyBC

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 March 26, 2010, 12:29 Generating a parabolic Profile with groovyBC #1 New Member   Andreas Join Date: May 2009 Location: Germany Posts: 13 Rep Power: 9 Hi, How can i generate a parabolic velocity profile with groovyBC? The entry in the openfoamwiki isnt really helpful. The example "parabolic inlet condition that pulsates " generates an error and i cant find any "real" documentation. If someone could point me to the solution i would be really grateful.

 March 27, 2010, 06:47 #2 New Member   Andreas Join Date: May 2009 Location: Germany Posts: 13 Rep Power: 9 I managed to get a parabolic profile with Code: ```variables "w=0.00005;m=3;n=2;Umax=1*(m+1)*(n+1)/m/n;c=pos().y-w;d=pos().z-w;a=pow((c/w),2);b=pow((d/w),2);speed=Umax*(1-a)*(1-b);"; valueExpression "vector (speed, 0, 0)";``` in my starting file for U but i have two problems. pow() does not accecpt non integer values for the exponent like pow(a,1.5) is this a "normal" behaviour? and i need some function to get the distance from a point like distance = pos().z-w now this will result in an negative value if pos().z

March 27, 2010, 09:14
#3
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Sebastian Gatzka
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Quote:
 Originally Posted by erklaerbaer I managed to get a parabolic profile with Code: ```variables "w=0.00005;m=3;n=2;Umax=1*(m+1)*(n+1)/m/n;c=pos().y-w;d=pos().z-w;a=pow((c/w),2);b=pow((d/w),2);speed=Umax*(1-a)*(1-b);"; valueExpression "vector (speed, 0, 0)";``` in my starting file for U but i have two problems. pow() does not accecpt non integer values for the exponent like pow(a,1.5) is this a "normal" behaviour? and i need some function to get the distance from a point like distance = pos().z-w now this will result in an negative value if pos().z
Strange, pow() should be able to deal with floating point exponents ...
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March 29, 2010, 14:31
#4
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Bernhard Gschaider
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Quote:
 Originally Posted by erklaerbaer I managed to get a parabolic profile with Code: ```variables "w=0.00005;m=3;n=2;Umax=1*(m+1)*(n+1)/m/n;c=pos().y-w;d=pos().z-w;a=pow((c/w),2);b=pow((d/w),2);speed=Umax*(1-a)*(1-b);"; valueExpression "vector (speed, 0, 0)";``` in my starting file for U but i have two problems. pow() does not accecpt non integer values for the exponent like pow(a,1.5) is this a "normal" behaviour? and i need some function to get the distance from a point like distance = pos().z-w now this will result in an negative value if pos().z
According to the grammar file power should work with any scalar-constant as an exponent. It doesn't work with expressions. So something like pow(p,T) or even pow(p,3./2) are NOT possible. What is the expression that is not working for you and what is the error message?

Bernhard

 April 7, 2010, 15:42 #5 New Member   Andreas Join Date: May 2009 Location: Germany Posts: 13 Rep Power: 9 Sorry for answering so late; I solved the problem another way. I think (I did and learned a lot inf and of OpenFOAM the last days) I just missused the Expression.

 June 4, 2010, 15:18 groovyBC #6 Senior Member   Join Date: Jan 2010 Location: Stuttgart Posts: 144 Rep Power: 8 Hi, Can someone tell me how I can use groovyBC? I read the article in OpenFoamWiki http://openfoamwiki.net/index.php/Co...rds_of_warning, but I do not understand this part: 1.2 Pre-requisites To compile this utility Bison has to be installed. The compilation is known to work with version 2.4.1. It may probably work with older versions. Check with bison -V on the command line before trying to compile it and report the version number when reporting a problem. 2 Usage 2.1 Compilation and installation Just do wmake libso in the directory of the sources. The library will be compiled and installed in a place (%FOAM_USER_LIBBIN) where it is usable I installed bison 2.4.1 like it is written in the install-file: ./configure make make install where do I now have to write "wmake libso"? What means "in the directory of sources"? Best Regards Chrisi

 June 6, 2010, 03:54 #7 New Member   Andreas Join Date: May 2009 Location: Germany Posts: 13 Rep Power: 9 Hi Chrisi, you have to type "wmake libso" in the directory of groovyBC. The directory "make" should be in that directory where to type "wmake libso". -- Wenn du wmake eintippst sucht das Skript nach dem Ordner Make und dort nach den Steuerdateien, deswegen musst dein aktuelles Arbeitsverzeichnis Der Ordner sein wo der Ordner "make" drinliegt.

 June 6, 2010, 11:59 #8 Senior Member   Join Date: Jan 2010 Location: Stuttgart Posts: 144 Rep Power: 8 Thank you, I tried to do so but, I have a problem in compiling groovyBC. I am using OF 1.6.x. I have bison (GNU Bison) 2.4.1 and flex 2.5.35. I copied all the files of groovyBC from here https://openfoam-extend.svn.sourcefo...ries/groovyBC/. and put it into my run folder. When I compile it I get the following error: root@chrisilinux:~/OpenFOAM/OpenFOAM-1.6.x/lib/linuxGccDPOpt/groovyBC# wmake libso wmakeLnInclude: linking include files to ./lnInclude make: *** Keine Regel vorhanden, um das Target »PatchValueExpressionDriver.dep«, benötigt von »Make/linuxGccDPOpt/dependencies«, zu erstellen. Schluss. root@chrisilinux:~/OpenFOAM/OpenFOAM-1.6.x/lib/linuxGccDPOpt/groovyBC# I yet tried compiling with out coomented groovyBCPointPatchFields.C, but it did not help. Can you help me compilling groovyBC? Thanks in advance. Regards Chrisi

 June 6, 2010, 12:54 #9 New Member   Andreas Join Date: May 2009 Location: Germany Posts: 13 Rep Power: 9 okay ähm. You ned to install "svn" if it isnt already there. Then go to a location of your choice, eg run/user_apps or whatever and paste the following line in the console Quote: and hit Enter, svn will then download all files you ned. After svn did its job there should be a ne folder, go with the shell to the appropirate folder (where there is a subfolder "make") and enter "wclean" and than "wmake libso". Should work If there comes an error just post it here. Currently i have no OpenFOAM installed (or any linux) but i survived installing groovyBC

 June 6, 2010, 14:51 #10 Senior Member   Join Date: Jan 2010 Location: Stuttgart Posts: 144 Rep Power: 8 Thank you erklaerbaer!! Vielen Dank!! Dann kann ich jetzt mal versuchen damit zu arbeiten. Now I can use groovyBC!! Regards Chrisi

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