Design and performance analysis of a novel face gas seal

Abstract

The scope of this work carried two objectives, each focusing on theoretical model development, performance prediction and experimental evaluation of two concepts, of face type non-contacting gas seals. The theoretical modelling and experimental testing were undertaken across a high duty-operating envelope up to 300 bar, 12000 rpm and 1200 C. For both sets of experiments, specialised test equipment and test rig were designed and built.

The first objective was to determine the performance of a slot feed design of non-contacting gas design, by evaluating its performance across the full performance envelope. A set of test seals was made for experimental evaluation. A suitable computer model was developed and validated against experimental data. Results showed good seal performance across the main duty conditions and the model showed good correlation with the experimental test data.

Under the second objective, a totally novel design of non-contacting gas seal was proposed, incorporating a unique lift groove geometry (patent pending). A novel and sophisticated computer model was developed to accurately predict the performance of this design. The model was made fully coupled between the fluid and structural domains of the gas seal.

The model predictions were verified against the experimental data. The correlation between the two was found to be very close and consistent across the entire performance envelope of the seals. The novel design concept performed extremely well under all the test conditions, both real and artificial. The theoretical model developed as part of this research proved itself to be an effective analysis and performance prediction tool.