Non-Axisymmetric Brush Seal Assembly for Flutter and Leakage

The patent applies asymmetry by designing a non-axisymmetric bristle tip projection surface where the bristle tips are positioned at different radial distances from the central axis. Specifically, the bristle pack includes bristles at a first radial distance and other bristles at a second radial distance that is different from the first radial distance. This asymmetric configuration disrupts the symmetric flow patterns that cause self-feeding vibrations and air leakage, thereby improving reliability while maintaining manufacturing feasibility through straightforward bristle arrangement methods.

The patent applies local quality by creating zones with different bristle characteristics within the same bristle pack. Specifically, certain bristles are positioned at a first radial distance with specific properties while other bristles are positioned at a second radial distance with different properties. This allows localized optimization of sealing performance in different circumferential zones, improving overall reliability without requiring complete redesign of the entire seal assembly, thus limiting the increase in device complexity.

The patent applies asymmetry to the gap configuration by positioning the gap between the bristle tips and the seal land such that the gap position and width vary circumferentially. Specifically, the gap is positioned at different locations and with different widths at different circumferential positions, creating an asymmetric flow path that disrupts flutter-inducing vibrations. This approach reduces harmful flutter magnitudes while the manufacturing precision requirements are managed through the modular bristle pack design that allows for controlled variation in gap dimensions.