[sanjar]

Hey guys, i simulate with simpleFoam and used in paraview the Filter PlotOverLine.

Now I wanted to compare my results at this certian discrict shown with plotOverLine with simulation from ANSYS (with the same boundary conditions).
The problem is, that the scale at the y-axis in paraview is different than the one in ANSYS. I wanted to show the pressure on the certain district.

For example: Simulation in OpenFOAM shows a peak in paraview of around 120 (13m/s)
The simulation in ANSYS provides a peak of around 90000 Pascal.

My problem is that i dont have a unit on my y axis in paraview.
i tried to work with the pressure coefficient.
http://en.wikipedia.org/wiki/Pressure_coefficient

anyone has another idea??

the pics are attached.

thank you !!

[jherb]

simpleFoam uses pressure normalized by density, so to compare the values with ANSYS you have to multiply the values of OpenFOAM with the density (see also the dimension of pressure in the file 0/p).

[sanjar]

hello joachim

thank you for your response. Are you german or do you speak at least german? (wenn ja, dann kann man sich vll bei komplizierteren beschreibungen auf deutsch ausdrücken).

i found a formular in this forum which works quite good for my graps, which is p0= p + (0.5*density * U²). I integrate this formula into "Calculator" and used after that PlotOverLine. See my pics attched, that it works pretty good.

now i have a new problem, namely the beginning and the end of the graphs. they dont begin and end at zero but at a part above 0. the reason is, because i used my velocity which is constantly 13 m/s (so ist put in p+ (0.5 * density * 13²) and not the velocity in paraview which is used as the vector. (see pic attached).
but actually i have to use the value of the scalar for the velocity. but paraview gives the follwoing error out:

p, li { white-space: pre-wrap; } ERROR: In /home/sanjar/OpenFOAM/ThirdParty-2.2.x/ParaView-3.12.0/VTK/Charts/vtkPlotPoints.cxx, line 641
vtkPlotLine (0xdc0b280): No Y column is set (index 1).


maybe you know the reaosn why it is not possible to integrate my velocity as the vector. i wanted to test it out with PlotOverLine for velocity and it gives me a velocity of 9 m/s out. but thats not possible, it has to be 13 m/s


do you have any idea why it is not possible to work with me velocity as a scalar in calculator?
thanks