Flow configurations Regime

These flow configurations are grouped into the five basic flow regimes defined by Cichy et al. (the numbers refer to the above list) ... 

This regime is characterized by the presence of one continuous fluid phase and one discrete fluid phase in tubular systems. The existence of the discrete phase generates a large interfacial area per unit tube volume for all flow configurations included in this regime. For that reason, Regime IV is of pragmatic interest when interphase heat and mass transfer are of key importance. 

Bio)chemical sensors can be used in both the batch and the continuous mode. While this is also true of probe-type sensors, flow-through sensors can only be used in a continuous regime coupled on-line to a continuous-flow configuration. 

Typically, TSOFC use co- and counter-flow configurations whereas planar stacks sometimes favour cross flow simplifying manifolds attachment. The flow of air usually provides cooling to a stack in either design as does internal reforming (Sulzer Hexis). The flow regime strongly affects the distribution of gas composition, mechanical stress, stack temperature and ultimately current density. 

The domain of the mixed convection regime depends on the fluid the flow configuration and the flow pattern (17). It is usually defined by a region a < Gr/Re < b where a and b are the lower and upper bounds of the domain respectively and Gr/Re is the buoyanct force parameter n being a constant that varies with the flow configuration. Conversely when the buoyant force is the dominant mode of transport Re /Gr or some power of it becomes the important parameter for mixed convection. 

Based on the dimensionless equation of continuity [i.e., eq. (12-18dimensionless equation of motion [i.e., eq. (12-18e)] in the laminar flow regime, one concludes that both v and v are functions of dimensionless spatial coordinates x and y, as well as the Reynolds number and the geometiy of the flow configuration. Unfortunately, the previous set of equations does not reveal the specific dependence of v and v on Re. 

Flow and power numbers each decrease as the Reynolds number increases. In unbaffled tanks, a vortex forms that takes over the flow regime and does not allow the usual relationship to describe the performance of the mixing operation. It is proper and good practice to provide baffles in all vessels (see later description for the physical configurations). 

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