I want to implement the following integral as a weak constraint on curved surface boundary in COMSOL. How is it possible?. In the literature, i have searched that this can be implemented as weak contribution with components as, test(uTx) and test(vTy) with Lagrange multiplier . But I really feeling problems in its implementation here.

surface gradient operator=Del s

test function=v

int(Del s v) d s.

Thanks.