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Thermohydrodynamics of bidirectional groove dry gas seals with slip flow

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journal contribution
posted on 15.08.2016, 12:41 authored by H. Su, Ramin RahmaniRamin Rahmani, Homer Rahnejat
Thermo-hydrodynamic behaviour of bidirectional dry gas seals with trapezoidal shaped symmetric grooves is studied. A multi-physics model, coupling compressible laminar flow and heat transfer in both the fluid and the solid bodies is used in a multi-physics modelling environment. The multi-physics model also includes slip flow conditions, corresponding to relatively high Knudsen numbers, as well as the effect of asperity interactions on the opposing seal faces. A comparison of the seal performance under isothermal and thermal flow conditions shows the importance of including the thermal effects. The difference in the predicted opening force between isothermal and thermal model can exceed 2.5%, which is equivalent to a force of around 1 kN. The importance of designing gas seals to operate at the minimum possible gap to reduce power losses as well as leakage from the contact is highlighted. However, it is shown that there exists a critical minimum gap, below which the power loss in the contact can abruptly increase due to asperity interactions, generating significantly increased operating temperatures.



  • Mechanical, Electrical and Manufacturing Engineering

Published in

International Journal of Thermal Sciences




270 - 284


SU, H., RAHMANI, R. and RAHNEJAT, H., 2016. Thermohydrodynamics of bidirectional groove dry gas seals with slip flow. International Journal of Thermal Sciences, 110, pp. 270-284.


© Elsevier


AM (Accepted Manuscript)

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This paper was accepted for publication in the journal International Journal of Thermal Sciences and the definitive published version is available at