[Anuranga999]

how to find pressure co-efficient in openfoam ?
hope your kind consideration for this. im validation openfoam by using onera m6 wing

[Bazinga]

You can get the pressure using probes (time history at specific points) or the sample utility (values at one time step). If you have the pressure, calculating the pressure coefficient can be done by yourself. For mean pressures you need to add information about the averaging in the controlDict file. Search the forum/web for information. Let me know if you have more questions.

[kalpa]

Originally Posted by Bazinga

You can get the pressure using probes (time history at specific points) or the sample utility (values at one time step). If you have the pressure, calculating the pressure coefficient can be done by yourself. For mean pressures you need to add information about the averaging in the controlDict file. Search the forum/web for information. Let me know if you have more questions.

thank you sir for your consideration we are validating openfoam using OneraM6 wing. we used simplefoam and we modeled it in solid works and adding snappyhexmesh and done. we have postprocessing file and time variables afer done the simulation. but we dont know what are the pressure values and how to calculate Cp from it. we used K omega , SparateAlmaras models. plz be kind consider on that and give comments on that

[Bazinga]

The pressure values for each time are stored in the time directories in the files named "p". look in any textbook to find the formulation of the pressure coefficient: is (total pressure-reference pressure) /dynamic pressure. The denominator is the value that you find in the "p" files.

[kalpa]

Originally Posted by Bazinga

The pressure values for each time are stored in the time directories in the files named "p". look in any textbook to find the formualtion of the pressure coeffiecient:it is total (pressure-reference pressure) /dynamic pressure. Am on phone atm check the exact formula by yourself.

SIR each time there is a P foder, but it cant open, and also there is a Cuttingplane folder in postprocessing folder, in that folder P_yNormal.vtk and U_ynormal.vtk are there. In P_yNormal.Vtk file there are many values. is that pressure values or ?

[vikramaditya91]

Hello Kalpa. A quick search showed me this:

Originally Posted by naveen

hi all,

If you want to calculate the Cp from paraview, do the following procedure

1) convert the simulated results into vtk format
2) install the binary pack of paraview (later versions like 3.4, 3.6 or 3.8)
3) open the converted vtk format of the patches you want to calculate Cp (like wing, airfoil) in paraview
4) In paraview, at the left hand side, there is a function called split vertical command, click on that and click on spreadsheet view
5) after opening spread sheet view select the cells option or point option in paraview on right side of the paraview window
6) in that you wil get the pressures on all the cells on your patch
7) in the paraview window there is an option called file--------->export (export this into cvs file format)
8) open this cvs format in excell sheet and perform the calculations by using the formula Cp=(p-p0)/0.5*rho*v*v for 1 cell and drag all the values there...you wil get cp values for your patch


Regards

Naveen.K.M
CFD Engineer
National Aerospace Laboratories
Bangalore

You can read upon this, at http://www.cfd-online.com/Forums/ope...-openfoam.html