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Center of Pressure Output

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Old   April 12, 2021, 23:50
Default Center of Pressure Output
  #1
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Juan Salazar
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Hello,

I am a recent user of SU2 and I noticed that the center of pressure result in the forces_breakdown.dat file is rather awkward. I find the following line in the file for an airfoil simulation (2D):

Code:
Center of Pressure: X=0.300838Y+0.239842 m.
The relevant source code I found is in CFlowOutput.cpp (version 7.1.1 "Blackbird"). In earlier versions it is in output_structure.cpp

Code:
    /*--- Begin forces breakdown info. ---*/

    Breakdown_file << fixed;
    Breakdown_file << "\n" << "\n" <<"Forces breakdown:" << "\n" << "\n";

    if (nDim == 3) {
      su2double m = solver_container[FLOW_SOL]->GetTotal_CFz()/solver_container[FLOW_SOL]->GetTotal_CFx();
      su2double term = (Total_CoPz/m)-Total_CoPx;

      if (term > 0) Breakdown_file << "Center of Pressure: X="  << 1/m <<"Z-"<< term << "." << "\n\n";
      else Breakdown_file << "Center of Pressure: X="  << 1/m <<"Z+"<< fabs(term);
      if (config->GetSystemMeasurements() == SI) Breakdown_file << " m." << "\n\n";
      else Breakdown_file << " in." << "\n\n";
    }
    else {
      su2double m = solver_container[FLOW_SOL]->GetTotal_CFy()/solver_container[FLOW_SOL]->GetTotal_CFx();
      su2double term = (Total_CoPy/m)-Total_CoPx;
      if (term > 0) Breakdown_file << "Center of Pressure: X="  << 1/m <<"Y-"<< term << "." << "\n\n";
      else Breakdown_file << "Center of Pressure: X="  << 1/m <<"Y+"<< fabs(term);
      if (config->GetSystemMeasurements() == SI) Breakdown_file << " m." << "\n\n";
      else Breakdown_file << " in." << "\n\n";
    }

The way it is being written, it looks like an equation. What am I missing here?
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Old   April 13, 2021, 04:41
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pcg
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Pedro Gomes
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You are not missing anything, it is the equation for a line.
It is discussed here https://github.com/su2code/SU2/discussions/1227
(you'll need to scroll down a bit)
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