On a variational principle for the Upper Convected Maxwell model

A variational principle for the Upper Convected Maxwell model is presented. The stationary value of appropriate functional drag on an immersed object. From principle, a formula derived derivative with respect to Deborah number arbitrarily shaped particle in circular duct under creeping flow conditions. formalism compared conventional reciprocal theorem. Whereas theorem gives as volume integral involving Stokesian stress tensor, involves from adjoint equation. For low numbers both approaches provide correction Stokes only rate-of-strain line second-order fluid theory.