Numerical Analysis on Improving the Rectangular Texture Floating Ring Gas-film Seal Characteristics with Different Bottom Shapes

Abstract

Finding the right texture pattern to effectively improve the sealing performance of the floating ring gas film seal has always been a topic of interest for engineers. Herein, to reveal the effect of the rectangular textured base shape on the sealing characteristic parameters of floating ring gas film seal, four bottom shapes of rectangle, isosceles triangle, left triangle and right triangle were proposed. The governing equations were solved by the finite difference method and the correctness of the theoretical results was verified by the test bench. The effect of operating conditions parameters on the sealing performance were also analyzed. The results reveal that the trends of the experimental results is consistent well with the theoretical results, in which the relative errors are all less than 9%. It indicates that the theoretical model is scientific and valid. As the speed and inlet pressure increase, the texture bottom shape significantly changes the distribution of pressure and temperature field. And the average gas film thickness determines whether the texture produces an effect or not. Under the same operating conditions, a right-angled triangular bottom shape can obtain a good stability and cooling effect for the sealing device. With a bottom shape of the right triangle and a bottom shape of the rectangle, the maximum difference in opening force and gas film temperature rise were calculated to be 234.91 N and 0.61 oC, respectively. The research results provide theoretical support for further study of the textured floating ring gas film seal and a reference for texture optimization.