Numerical Investigation of Gas Film Performance in Face Dry Gas Seals with Combined Micro-Textured Structures

To enhance the load-carrying capacity and operational stability of dry gas seal gas films while reducing gas leakage, and to provide a theoretical basis for structural optimization and innovation of face seals, a numerical model of gas film lubrication in face dry gas seals considering the geometric effects of combined micro-textures is developed based on the governing equations of gas lubrication. The finite difference method is employed to numerically solve the gas film pressure distribution. With the objectives of maximizing the opening force and minimizing the leakage rate, the influences of combined micro-texture structural parameters on gas film performance under typical operating conditions are systematically investigated, and favorable parameter ranges are identified. The results show that the proposed model exhibits high accuracy and reliability, with good agreement with published data. Different combined groove textures significantly affect the gas film thickness and pressure distributions, leading to distinct bearing and stability characteristics. When opening force and leakage are jointly considered, the sealing performance ranks as triangular composite texture, semicircular composite texture, rectangular composite texture, and trapezoidal composite texture. Quantitatively, the trapezoidal texture exhibits the largest increase in the opening force–leakage ratio of approximately 0.29%, whereas the triangular texture shows the smallest increase of about 0.19%. Reasonable design of combined micro-textures can effectively improve the comprehensive gas film performance of face dry gas seals, achieving a coordinated enhancement of opening force and reduction in leakage. The present study provides theoretical guidance for the structural design and engineering application of high-performance dry gas seals.