Static Characteristics of Annular Damper Seals With Square-Hole Pattern Stators in Turbulent Regime

为了提高泵的效率和稳定裕度，人们提出了各种密封结构。前人的实验结果证实，与光滑表面的常规环形平面密封相比，故意改变定子表面粗糙度图案的阻尼器密封将产生更小的交叉耦合刚度系数、更大的主阻尼系数和更低的泄漏流量。本文对方孔型定子环形阻尼器密封的静、动态特性进行了理论和实验研究。理论研究中采用了带湍流系数的平均Navier-Stokes方程和连续性方程，并考虑了方孔各台阶流道的压力损失进行了数值求解。根据“壁面定律”和普朗特混合长度假设计算了湍流系数。计算结果总结为…(1)仅通过转子在密封中心的旋转运动得到的密封间隙内的泄漏流量和压力分布等静态特性的数值结果与测量结果吻合较好，验证了理论分析的有效性。(2)转子旋转和旋转运动所得到的动态特性(动液力和动态系数)的数值结果与测量结果定性一致。计算结果与实测值基本吻合。(3)周向阶梯压力损失主要影响切向动力流体力，增加了主阻尼系数，而轴向阶梯压力损失降低了泄漏流量。这些事实有助于设计具有最佳结构的环形密封，从而产生更好的密封特性。较少

For improving the efficiency and the stability margin of pumps, various seal configurations have been proposed. The previous experimental results confirmed that damper seals with intentionally different stator roughness surface pattern would yield smaller cross-coupled stiffness coefficients, larger main damping coefficients and a lower leakage flow rate than conventional annular plain seals with smooth surfaces. In the present study, the theoretical and experimental investigations of the static and dynamic characteristics are carried on the annular damper seals with square-hole pattern stators. Averaged Navier-Stokes equation with turbulent coefficients and continuity equation are applied to the theoretical investigation, which are numerically solved in consideration of the pressure loss due to the flow passage across each step of square holes. The turbulent coefficients are calculated based on the "law of the wall" and Prandtl's mixing length hypothesis.The results are summarized as … More follows:(1) The numerical results of the static characteristics, i.e., the leakage flow rate and the pressure distributions in the seal clearance obtained only by the rotor spinning motion at the seal center are good agreement with the measured results, which verifies the validity of theoretical analysis.(2) The numerical results of the dynamic characteristics, i.e., the dynamic fluid force and the dynamic coefficients obtained by both spinning and whirling motions of the rotor, qualitatively agree with the measured results. In particular, the quantitative agreement of the main damping coefficients is obtained between the numerical and measured results.(3) The pressure loss at the steps in the circumferential direction influences mainly the tangential dynamic fluid force and increases the main damping coefficients, whereas the pressure loss at the steps in the axial direction decreases the leakage flow rate. These facts contribute to the design for the annular seals with the optimum configurations yielding better seal characteristics. Less