The AIRSEAL test bench has been designed, manufactured, assembled, installed, and tested at COMOTI's facilities with the involvement of both project partners. Throughout the development and testing phases, the Topic Leader was engaged for validation of the intermediate and final results. At the end of the commissioning phase, the test bench was demonstrated to perform its functions within the entire working envelope: up to 15,000 rpm, up to 150 °C, pressure ratios of 0.5 to 1, with the pressure difference under 2 bar, and with data recording as required.
For the actual test campaigns, three specific labyrinth seals (consisting of a stator and a rotor, working together to minimize gas leakage) were manufactured according to Topic Leader specifications. The seals met dimensional requirements and their conformity was documented throughout the manufacturing process. The geometry and characteristics of the rotors and stators were defined as per Topic Leader requests.
The commissioning and testing of the AIRSEAL Test Bench and the completion of test campaigns #1 and #2 have provided a wealth of data on the performance of labyrinth seals tested in similar conditions of labyrinth seals of aerospace engines. A set of test data has been made available to the scientific community through the open access ZENODO repository proposed by the Clean Sky JU. The link to the data is
https://doi.org/10.5281/zenodo.7763679(opens in new window) .
The raw data files from the 720 tests performed have been processed and analyzed using a combination of automated and manual procedures, and the stabilized regimes (the actual tests) have been identified, graphically represented, and saved as individual files for ease of access and speed of processing. Regression analysis has been utilized to explore the correlation between the dependent variable (response - airflow) and the independent variables (predictor variables – pressure ratio, rotor speed, temperature, and clearance) to develop a mathematical model that includes linear, quadratic, and interaction terms.
Regarding the further exploitation of the project results, the Topic Leader is planning to calibrate a CFD model of the test rig based on experimental tests, with the aim of establishing a numerical methodology capable of accurately predicting labyrinth seal performance. Discussions with the Topic Leader are ongoing to expand research and development on labyrinth seals, taking into account the extensive range and high levels of operating parameters provided by the AIRSEAL Test Bench. The acquired know-how will be utilized in new European research projects and commercial ventures within the aerospace and industrial sectors.
Project results were disseminated through various channels, including the COMOTI and AIRSEAL project websites, press articles, scientific papers, and conference participation. Additionally, the project was showcased at fairs, exhibitions, and academic presentations. The AIRSEAL project also facilitated the development of a complementary initiative, the INFRASEAL project, which focuses on a broader research infrastructure for rotating labyrinth seals characterization.
