38 lines
1.2 KiB
C
38 lines
1.2 KiB
C
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{
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//- calculate lift and drag for plate and cylinder due to pressure (ignore shear stress)
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label plateID = mesh.boundaryMesh().findPatchID("plate");
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label cylinderID = mesh.boundaryMesh().findPatchID("cylinder");
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if(plateID == -1 || cylinderID == -1)
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{
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FatalError << "\n Cannot find the plate patch or the cylinder"
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<< " patch to calculate lift and drag!"
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<< exit(FatalError);
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}
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scalar lift = 0;
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scalar drag = 0;
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const vectorField& Sfp = mesh.boundary()[plateID].Sf();
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forAll(p.boundaryField()[plateID], facei)
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{
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vector faceForce = p.boundaryField()[plateID][facei] * Sfp[facei];
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lift += vector(0,1,0) & faceForce;
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drag += vector(1,0,0) & faceForce;
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}
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const vectorField& Sfc = mesh.boundary()[cylinderID].Sf();
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forAll(p.boundaryField()[cylinderID], facei)
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{
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vector faceForce = p.boundaryField()[cylinderID][facei] * Sfc[facei];
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lift += vector(0,1,0) & faceForce;
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drag += vector(1,0,0) & faceForce;
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}
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scalar width = 0.050668;
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Info << "Total lift on the cylinder and plate boundaries is " << lift << " N, per unit width is " << (lift/width) << " N\n"
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<< "Total drag on the cylinder and plate boundaries is " << drag << " N, per unit width is " << (drag/width) << " N\n"
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<< endl;
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}
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