Analysis of leakage characteristics and structural optimization of two-stage floating ring seal

Abstract Two-stage floating ring seal is a non-contact circumferential seal with low leakage and high reliability. This paper elaborates on the variation mechanism and calculation method of the working clearance and working conditions of sealing chamber, reveals the corresponding relationship between operating conditions of aircraft engine and leakage characteristics of two-stage floating ring seal, obtains an effective method for analyzing the leakage characteristics of two-stage floating ring seals. The pressure of sealing chamber can be determined by continuously assuming the pressure of sealing chamber and substituting it to continuity equation. Carry out leakage characteristic experiments under specific operating conditions, the minimum deviation between the value of calculation and the experimental results is −11.47 %, the maximum deviation is 7.34 %, and the average of the absolute value of deviation is 5.01 %. The optimization design scheme for the working clearance and the intermediate air flow channel have been proposed, which can provide important support for improving the reliability and sealing performance of the two-stage floating ring seal.