Flow visualization and motion analysis for a series of four sequential brush seals

Applying the full-flowfield-tracking (FFFT) method, the flow patterns and the accompanying fluid velocities inside a series of brushes were nonintrusively determined and graphically reconstructed. The visualized flowfield, Braun et al. revealed regions that are characteristically river jetting, vortical, crossflow, and exist upstream, downstream, or within the seal. These flows are especially engendered by variations of fiber void that are spatial and temporal and affect changes in seal leakage and stability. The deformation of the upper half of each of the four sequential brushes as a function of upstream pressure and mass flow was determined. The axial pressure variation across the set of four brushes and the mass flow as a function of the pressure drops are also presented.