The problems of hydromechanics are solved by the rheological law of a joint consideration for the mechanisms of molecular and molar transfer of substances in the flow. Molecular transfer in the flow is taken into account by Newton's rheological law, and to account for the molar transfer of a substance in the flow, the stress is taken in direct proportion to the derivative of the normal acceleration. The terms with third-order derivatives are formed when two transfer mechanisms are taken into an account in the Navier-Stokes equations. The monograph contains the results of scientific research...