
Overview
FLUENT provides the ability to calculate streamwiseperiodicor "fullydeveloped''fluid flow. These flows are encountered in a variety of applications, including flows in compact heat exchanger channels and flows across tube banks. In such flow configurations, the geometry varies in a repeating manner along the direction of the flow, leading to a periodic fullydeveloped flow regime in which the flow pattern repeats in successive cycles. Other examples of streamwiseperiodic flows include fullydeveloped flow in pipes and ducts. These periodic conditions are achieved after a sufficient entrance length, which depends on the flow Reynolds number and geometric configuration.
Streamwiseperiodic flow conditions exist when the flow pattern repeats over some length , with a constant pressure drop across each repeating module along the streamwise direction. Figure 9.4.1 depicts one example of a periodically repeating flow of this type which has been modeled by including a single representative module.
Limitations for Modeling StreamwisePeriodic Flow
The following limitations apply to modeling streamwiseperiodic flow: