creating a field function
Hello,
I am working on a project where I have to simulate the flow of air through a pipeline. I want to create the velocity inlet profile on star ccm+. How do I implement this function into the program. funktion : 2E08z^4 + 2E05z^3  0,007z^2 + 1,03z 4,578 Thanks in advance. Can 
(2*pow(10,8)*(pow($$Centroid[2],4))) + (2*pow(10,5)*(pow($$Centroid[2],3)))  (0.007*(pow($$Centroid[2],2))) + (1.03*($$Centroid[2]))  4.578
In the above formulation you can also use $$Position[2] instead of $$Centroid[2] is thats what you need. To implement the field function on the boundary Region > Boundaries> Physics Values > Velocity Magnitude (Method > field function) 
(2 * Pow (10.8) * (pow ($ $ Centroid [2], 4))) + (2 * pow (10.5) * (pow ($ $ Centroid [2], 3)))  (0.007 * (pow ($ $ Centroid [2], 2))) + (1.03 * (pow ($ $ Centroid [2], 1)))  4.578
I have the equation changed(red color), ist dies correct? and if I have this equation enter into the program, I get error message "Compiled field function type is not vector " Thanks in advance. Can 
Quote:
(2 * pow (10,8) * (pow ($$ Centroid [2], 4))) + (2 * pow (10,5) * (pow ($$ Centroid [2], 3)))  (0.007 * (pow ($$ Centroid [2], 2))) + (1.03 * ($$ Centroid [2]))  4.578 In the pow command variables are separated with commas. Also, no space between the two $$ signs. 
Thank you for your effort, unfortunately, does not again.diese equation is a velocity distribution in a Pipe.
I have descriped cylindrical coordinatesystem in the Inlet .it must be the Origin in the middle? Part(Pipe) has a symmetry Plane :) 
Sure that he need to write the E8 as a pow?
Normally it works without this fine?! 
Hi,
I have changed the equation again. 0.00000002 * (pow ($$ Centroid [2], 4)) + 0.00002 * (pow ($$ Centroid [2], 3))  0.007 *(pow($$ Centroid [2], 2)) + 1.03 * ($$ Centroid [2])  4.578 Unfortunately, I get the same error message again,"Compiled field function type is not vector " Thanks 
Have you changed the field function 'Type' to vector?
I don't get this error message. I am using an older version of STAR CCM+. I will check it with the new version later and let you know. 
Hmm is the function set a scalar?

No, I have field function 'Type' Scalar. I am using version 4.2 of STAR CCM+. how did they coordinate system defined?

for vector definition, the three velocity components are described [x,y,z]. I guess in your case it would be
[0,0,0.00000002 * (pow ($$ Centroid [2], 4)) + 0.00002 * (pow ($$ Centroid [2], 3))  0.007 *(pow($$ Centroid [2], 2)) + 1.03 * ($$ Centroid [2])  4.578] 
4.2? You mean 4.02? ;)
In the properties you have the function type. Make a screenshot. 
Quote:

Quote:
That is really unbelievable. This works. I am very grateful for their help:D 
Quote:
course V4.02:( 
@SKK: Maybe you should make a benchmark for this extra pow function :D :D :D
A other way would be to use $Centroid_i (maybe a "cleaner" way). Of cource you need the vector "style" for the velocity :D I make too much 2D :D 
All times are GMT 4. The time now is 07:36. 