ENTROPY GENERATION IN MULTIFIELD FLOWS - EQUATIONS AND EXAMPLES OF APPLICATIONS

A general steady-stare entropy field equation and its corresponding ju mp conditions for multifield, multicomponent one-dimensional flows wit h heat and mass transfer are derived. In so doing, use has been made o f the stationary field equations of species continuity, total continui ty, momentum, and total energy, as well as canonical thermodynamic rel ations. Using the general equations, an expression for the rate of ent ropy generation in separated steady-state two-phase flow with entrainm ent is presented. Two examples of applications to this type of flow ar e given: estimation of void fraction based on the principle of minimum entropy generation at stationary states, and estimation of the thermo dynamically optimal tube diameter for specified mass and heat flow rat es (thermodynamic design of tubes).