paraInduced is a ParaView-Pythong script meant for extracting circulation and calculating the induced drag of a wing or airplane. It has so far only been used with OpenFOAM cases, but other formats can be analyzed with some modification.
The theoretical basis for the procedure is Munk's stagger theorem, according to which any lift producing object will have the same induced drag as a lifting line with the same spanwise distribution of circulation.
This script was written for use in a research work. Before use, it needs to be readjusted to the studied case, but it is not long or complex. It is currently only valid for wings without dihedral or winglets.
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Input all the necessary parameters in the SETTINGS section of the code.
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Load only the wing or airplane patch/patches into ParaView and switch to the correct time.
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In the Python shell, select Run Script, choose the correctly adjusted script and wait.
The output file paraInduced.log contains the induced drag coefficient and the span-wise distributions of circulation and downwash in dimensionless form in gnuplot-ready format.
Currently, the script works only for symmetric, half-domain cases. As is, the script is set for the left half-domain (looking in the direction of flight). The currently assumed, body-centered, right handed coordinate system, is oriented so that the x axis is colinear with the airplane chord and pointing "back", with the y axis pointing "up" and the z axis pointing left along the span. To use the script either the case has to be transformed to this coordinate system or the script has to be modified.
paraInduced was validated on the case of a high aspect ratio flat plate. The results obtained with OpenFOAM and paraInduced coincided excellently with the results obtained with Prandtl's lifting-line method.