I just made some correction, say, since pressure is defined in a space one order lower than velocity. In the last code I put all quadrature computation in velocity space by mistake, now I put the two integrals, $\int \tau * normal$ and $\int (-p)*normal$, into two separate sections and finally add their partial integral together.
Here are the comparison (for only pressure forces) 1) np=1 // the old one step 9, forces: (-1.299297e-01 3.460514e-03 0.000000e+00 ) step 9, moments: (0.000000e+00 0.000000e+00 7.266930e-05 ) 2) np=1 // the corrected one step 9, forces: (-1.799026e-01 -3.255020e-06 0.000000e+00 ) step 9, moments: (0.000000e+00 0.000000e+00 -9.115135e-07 ) 3) np=4 // the corrected one step 9, forces: (-1.799026e-01 2.098503e-06 0.000000e+00 ) step 9, moments: (0.000000e+00 0.000000e+00 5.020619e-07 ) when AOA=0.0 degree, the lift and z-pitching moment are dramatically reduced to zero. Now the question is the negative x-force. In the face quadrature, does fe_pres_face->get_normals() return all outward normal vector? Zhenyu ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
