干气密封端面气膜压力及开启力的数值模拟

为了全面了解干气密封端面流场特性，基于N-S方程、层流模型、SIMPLEC算法，在端面间隙和转速的多种变化情况下，对干气密封端面流场进行数值模拟，重点考察了端面气膜压力及开启力的变化情况. 数值结果表明，端面气膜压力总是在槽台交界处产生较大变化，在气体流出的槽台交界处产生流体动压力，而在气体流入的槽台交界处存在局部负压区域，会削弱端面开启力和气膜刚度. 通过合理设计槽形，增大正压区域的同时减小负压区域，可提高端面开启力和气膜刚度. 对比分析表明，通过优化槽形可大大提高端面开启力和气膜刚度，使密封更稳定.

Numerical Simulation on Pressure Distribution and Opening Force of Dry Gas Seal

For more details about flow field of dry gas seal, the numerical simulation is carried out based on the Navier-Stokes equation, laminar model, and SIMPLEC method, with various face clearances and rotating speeds. The distribution of film pressure and variation of opening force are investigated emphatically. The numerical results shows that at the intersection of groove and stage, there is clear change of film pressure, at the position of gas flow out, pressure increases, hydrodynamic pressure will be formed, at the place gas flows in, pressure decreases, negative pressure (relatively) zone will be formed, gas film stiffness and opening force will be weakened. Through rational groove shape design, enhancement of positive pressure zone and weakening of negative zone, higher opening force and film stiffness will be gained. Comparison analysis shows that opening force will be raised by new groove shape design, and higher stability is gained.