The Reduction of the Simple Hygrosteric Fluid to the Stokesian Fluid

This paper considers the derivation of the constitutive equation of the isotropic Stokesian fluid from the general constitutive equation of the isotropic first-order stress-rate hygrosteric fluid [1] on the basis that the Stokesian fluid is the limiting case of the hygrosteric fluid as the natural time of the latter tends to zero. One suggests the hypofluent liquid as a close approximation to the general first-order, stress-rate hygrosteric fluid. More general than the linear fluent body introduced by Noll [1], the hypofluent liquid possesses a constitutive equation allowing relatively easy application to flows of simple geometry for which experimental data may be obtained.