Numerical Study On Aerodynamic Performance And Reliability Affected By Groove Types Of Dry Gas Seals

Dry gas seal is a kind of non-contacting mechanical seals, which has lowerleakage, less wear, lower energy consumption and other advantages. Dry gas seals arewidely used in petroleum, chemical industry, metallurgy, aviation and other fields.The approximate model of parallel grooves based on the narrow groove theorywas used to establish the dynamic equations of gas film at end face seal. Thecorresponding nonlinear differential equations was numerically solved usingRunge-Kutta method and targeting algorithm to fast predict the aero-dynamicperformance at the seal face. The results match the Gabriel’s results very well. Thenthe fitting method of variables separation and the second-coupling fitting methodwere induced to obtain the coupling function between the opening force, leakage fluxand the inlet pressure, rotating speed. Using CFD numerical simulation method tocalculate Gabriel’s classic example, the comparison of numerical and narrow groovetheory results shows good conformity. Getting this conclusion that CFD numericalsimulation method has higher reliability when used in calculating dry gas seals.Confirming the right meshing method and boundary conditions， Then using thismethod in calculating herringbone grooves and bi-direction dovetail grooves.Comparing the aero-performance of these grooves, bi-direction dovetail grooves areused more widely than spiral grooves in bi-direction rotating conditions. Studyingleakage flux and opening force at the seal face, then getting the conclusions: workinggrooves play a major role in dry gas seal, non-client grooves don’t strengthen orweaken the seal ability noticeably. They are just satisfy bi-direction rotatingrequirements. Bi-direction dovetail grooves are more stable than single dovetailgrooves.Using CFD numerical calculation to calculate different typical grooves, gettingthe influence on performance of dry gas seals. This results can instruct theoptimization of grooves, the improvement of aero-dynamic performance and thedevelopment of new grooves.