Brush seal Resistance to Inlet Swirl and Transient Loading Effects (BRISTLE)

Air and other travel must become more energy-efficient to meet ambitious environmental targets set by the UK government and internationally. One key technology, which is important in determining efficiency and fuel burn, is engine seals. Challenges remain in deploying seals in the highest value locations, and in developing highly efficient novel system architectures which are enabled by reliable seals. Advanced shaft seals with compliant flexible elements can offer several advantages over the prevalent state-of-the-art, the labyrinth seal. These include increased tolerance of radial movements and shaft contact, and reduced leakage for a significantly reduced weight and space envelope. This research seeks to demonstrate that it is possible to expand the operating range and improve the robustness of one seal type, the brush seal, such that this can be used more widely in rotating machinery. Such sealing solutions can be used to improve the efficiency of current products, and also apply to future concepts including those with alternative working fluids and systems which are more electric. The Surrey University Brush Seal Iterative Simulator (SUBSIS) is able to capture the complex fluid-structure interaction within these adaptable seals, and shall be modified to investigate the resistance of the brush seal to high levels of inlet swirl consistent with those found at high shaft speed locations, for conventional and pressure-balanced brush seal configurations. The updated method will also allow for an assessment of the bristle-rotor tracking and seal leakage properties of these seal types under transient shaft incursion, associated with an offset (sweeping) or distorted rotor. These methods can be adapted to simulate any seal type with flexible elements in future research. Via academic and industrial collaboration, this work will contribute a significant forward step in delivering the sealing and power and propulsion technologies of the future.