Performance Analysis and Selection of a Bionic Bird Wing Multi-Array Spiral Groove Dry Gas Seal

A new type of bionic bird wing multi-array spiral groove dry gas seal was introduced to solve the problems that unidirectional spiral groove dry gas seal had poor operational stability and high leakage rate when it operated at high speed. With the gas lubrication theory,geometric model and mathematical model of bionic bird wing multi-array spiral groove were set up,and a series of simulations were carried out to analyze the influence of groove width in circumferential and radial direction on sealing performance like axial gas film stiffness and leakage rate,and optimization of the main geometric parameters of bionic bird wing multi-array spiral groove was demonstrated. Comparative analysis of different sealing performance like opening force,axial gas film stiffness,leakage rate and stiffness-leakage ratio between bionic bird wing multi-array spiral groove dry gas seal and common spiral groove dry gas seal in different outer pressure,linear velocity and film thickness was made,sealing performance contour map of these two types of grooves in different working conditions was presented. Numerical results show that sealing performance and stability of bionic bird wing multi-array spiral groove dry gas seal were much better when compared to unidirectional spiral groove dry gas seal at the condition of high speed and low pressure. The growing rate of axial gas film stiffness was more than 30%,the reduction amplitude of leakage rate was more than 10% in detail. The sealing performance contour map of bionic bird wing multi-array spiral groove dry gas seal provided a reference for the model selection and optimization design in engineering.