A Theoretical and Experimental Study on Characteristics of Water-Lubricated Double Spiral–Grooved Seals

Abstract

The spiral-grooved seal is a prime candidate for application to liquid oxygen (LOX) turbopumps. A theoretical model of double spiral–grooved seals dealing with the viscosity–temperature relation is presented. The effect of operating parameters (rotational speed, supply pressure) and configurative parameters (depth of spiral groove) on the basic static characteristics (opening force, leakage, static friction torque, face temperature, and power loss) of double spiral–grooved seals are examined. Comparisons are presented between measurements and theoretical predications for a narrow spiral-grooved face seal with an average diameter of 100 mm, operating at high speed and using water as a test fluid. The theoretical and experimental results indicate that the temperature on seal faces rises and friction torque increases with the speed and supply pressure, and these increases vary slightly with the depth of the spiral groove. These findings lend great theoretical and experimental insights to the design of face seals applied in liquid engine turbopumps.

KEY WORDS:

• Mechanical Seal (Face Seal)
• Hydrostatic Lubrication
• Water
• Rocket Engines

ACKNOWLEDGEMENTS

The authors are grateful to China Postdoctoral Science Foundation funded project with No.20100481367 and the international cooperation project of NPU, grant No. NTEA0001, for their financial support. The authors also thank X. S. Miao, S. K. Yang, B. Li, and the other experiment assistants at the Xi’an Aerospace Propulsion Institute of the China Aerospace Science and Technology Corporation, who provided assistance with the experimental process.

Review led by Richard Salant