LDV measurements in complex swirling flows, their physics and a database for CFD evaluations

摘要

In an earlier paper in this journal (Mocikat et al. in Exp Fluids 34:442–448, 2003) LDV measurements in a simple geometry but for a complex flow have been provided as a database for CFD evaluation purposes. With special inflow devices swirl could now be added to the flow. By changing the exit position of the test section in order to get a non-symmetric flow field, a steady swirling flow without instability induced precessing motions could be established. This flow can be interpreted as a superposition of a swirling motion to an otherwise swirl-free flow by introducing “swirl influence factors” for various aspects of the flow field. With a modified inflow device a periodically unsteady flow with swirl emerged. The turbulence features of this flow are distinctively different from the steady flow case with swirl. For all flows under consideration the three time-averaged components of the velocity vector and all components of the Reynolds stress tensor are measured in selected cross sections and provided as a data base for CFD calculations.