# [overture] Re: integrate force

*From*: Bill Henshaw <henshaw@xxxxxxxx>*To*: Yongsheng Lian <yongshenglian@xxxxxxxxx>, freelists <overture@xxxxxxxxxxxxx>*Date*: Thu, 03 Sep 2009 11:25:21 -0700

Hi Yongshen, You should define two surfaces, each with a different surfaceID and different set of faces. Regards, Bill Yongsheng Lian wrote:

Hi Bill, I was able to use the sharedBoundary option in aero.C. However, I ran into my first hurdle this morning when I looked into my problem. Since we want to get the forces on each of the two bodies, using command integrate.surfaceIntegral(f,surfaceID) will only get the total forces on both. I tried to use the following commands. The idea is to calculate forces on each individual grid. real drag[numberOfGrids]; for(i=0;i<numberOfGrids;i++) { drag[i] = integrate.surfaceIntegral(f(cg[i]),surfaceID); printf("on grid %i, the drag is %e \n",drag[i]); } The error message said integrate.surfaceIntegral(f(cg[i]),surfaceID) is not right. I traced back to the Integrate.h and find the definition of surfaceIntegral but have no idea how to define the Range. real surfaceIntegral(const RealCompositeGridFunction & u, const int & surfaceNumber = -1 ); int surfaceIntegral(const RealCompositeGridFunction & u, const Range & C, RealArray & integral, const int & surfaceNumber = -1 ); Can you give me some hints? Thank you, Yongsheng

**References**:**[overture] integrate force***From:*Yongsheng Lian

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- » [overture] integrate force - Yongsheng Lian
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