几何参数对刷式密封泄漏和刷丝尖端力的影响

Influences of geometric parameters on leakages and bristle tip forces in brush seals

建立了一种刷式密封的切片式三维模型,利用计算流体动力学(CFD)方法,计算了刷丝所受的气流力并将其简化为较少量的一系列的集中力.基于力矩平衡和线性叠加原理,提出了气流力引起的刷丝尖端力、转矩的一种定量计算方法.1台刷式密封实验台和1只实验刷环被用于相关理论计算的实验验证.基于上述理论计算,利用正交实验研究了刷丝长度、刷丝间隙、刷丝排数、安装角、刷丝直径和保护间隙对泄漏率、气流力、刷丝尖端力和转矩的影响.结果表明,总泄漏率及转矩的计算与实验结果基本吻合,各点误差均小于20%.刷丝直径、刷丝间隙、保护间隙及刷丝排数的对总泄漏率影响非常显著,安装角对转矩的影响非常显著.

Based on a type of three-dimensional slice model of brush seals in combination with the CFD method, the aerodynamic forces applied onto bristles were analyzed and simpli- fied to the concentration of a smaller amount of point forces. Bristle tip forces and torques caused by aerodynamic forces were quantitatively investigated using torque rebalance and lin- ear superposition principles. A test rig and a brush seal ring were applied to verify the relat- ed theory in test. Orthogonal tests were used to study the influences of the bristle length, inter-bristle spacing, bristle row number, lay angle, bristle diameter and protection clear- ance on leakage rates, aerodynamic forces, bristle tip forces and torques. Results indicate that the calculated total leakage rate and torques agree with the test data, the error at each point is less than 20~. The influences of bristle diameter, inter-bristle spacing, protection clearance, bristle row number on total leakage rate are very significant, and influence of the lay angle on torques are very significant too.