Polar theory for electrorheological fluids based on extended thermodynamics (Q2778213)

The methods of extended irreversible thermodynamics are applied to a polar fluid model for electrorheological fluids. In the first part of the paper, the fluid is described as non-polar. It is shown that certain well-known models emerge as special cases of rate-type constitutive equations for extra stress and electric displacement. In the second part, the induced structure of the fluid is accounted for by a polar theory. It is shown that only the polar model can account for different material responses if the constant electric field is oriented either perpendicular or parallel to the flow direction.