Quantifying safe operation of sustainable seals for rotating systems

Current sealing technology employed in rotating machines, such as aircraft turbine engines, high pressure turbo compressors and wind turbines, are reaching their maximum potential efficiency. Therefore, innovative sealing designs are necessary to meet the industrial demands for next generation machinery that require reduced leakage across the seal, decreased power losses and increased efficiency.

Non-contacting gas lubricated mechanical face seals have the potential to provide significant improvements in the sealing performance and meet the increased demand conditions. However, a key challenge is to provide safe and reliable operation under challenging, but feasible operating conditions, including potentially destabilising disturbances. The aim of this proposal is to develop theoretical capabilities to characterise the dynamic behaviour of a non-contacting gas lubricated mechanical face seal, which comprises of two discs; one fixed to a rotating shaft and the other mounted to a stationary housing with a thin fluid film separating the two. This design gives operational advantages over existing seals, including increased efficiency, decreased power losses and reduced costs over its lifetime. However, non-contacting seal technology has been described as unpredictable and unreliable, due to a high number of premature and unexpected experimental failures. By using a mathematical representation of the seal, investigations into the dynamic behaviour will enable understanding into the experimental failures and conditions on safe operation to be identified. Guidelines of sustainable seals will also be developed to provide improved sealing capabilities and performance envelop to ensure reliable and predictable behaviour.