Variational principles in hydrodynamics of a non-Newtonian fluid

In this paper, the principle of maximum power losses for the incompressible viscous fluid proposed by professor Chien Weizang in reference [1] is further extended to the hydrodynamic problem of the non-Newtonian fluid with constitutive law expressed as epsilon(y) = partial derivative tau/partial derivative sigma'(y). The constraint conditions of variation are eliminated by the method of identified Lagrangian multiplier and a generalized variational principle is established.