Energy exchange, between fluid

Convective heat transmission occurs within a fluid, and between a fluid and a surface, by virtue of relative movement of the fluid particles (that is, by mass transfer). Heat exchange between fluid particles in mixing and between fluid particles and a surface is by conduction. The overall rate of heat transfer in convection is, however, also dependent on the capacity of the fluid for energy storage and on its resistance to flow in mixing. The fluid properties which characterize convective heat transfer are thus thermal conductivity, specific heat capacity and dynamic viscosity. 

The overall heat transfer coefficient for thermal energy exchange between the tube wall and the reacting fluid may be taken as 1.0 x 10 3 cal/cm2-sec-°K. The effective thermal conductivity of the catalyst pellets may be taken as equal to 6.5 x 1CT4 cal/(sec-cm-°C). 

Energy exchange between the fluid and the solid phase is modeled as... 

Various flow problems involving evaporation and condensation phenomena are quite common in ordinary circumstances and have aroused an interest of scientists not only in the field of fluid dynamics but also of kinetic theory. The reason for this is that the ordinary continuum-based fluid dynamics cannot describe qualitatively correctly the process of evaporation and condensation occurring at the interface even in ihe continuum limit because of the existence of a nonequilibrium region, the thickness of which is of the order of the molecular mean free path, in the close vicinity of the interface between the condensed phase and the gas phase. Such a nonequilibrium region is called the Knudsen layer, in which collisions between molecules are not so frequent that the momentum and energy exchanges between the molecules leaving the interface... 

Adiabatic, except for heat exchange between fluids Insignificant potential and kinetic energy... 

The energy conservation model for the unheated horizontal and rising segments of the primary loop accounting for the potential for energy exchange between the fluid and the wall during transients is... 

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