Abstract:

Liquid self-impact sealing is a novel non-contact sealing technology that offers advantages such as zero wear, low energy consumption, long lifespan, and high stability, meeting the stringent sealing requirements under high-pressure and high-speed conditions. Through numerical simulations and multi-condition analyses, this paper systematically investigates the leakage characteristics and sealing mechanisms of wing-shaped, rectangular, and key-shaped suspension column structures, and proposes an optimized design method for parallel flow channels based on an analogy to Ohm's law. The study reveals that: (1) The wing-shaped suspension column structure exhibits the best leakage suppression capability under conditions of low-viscosity gas, high pressure (≥4 MPa), high speed (≥11000 r/min), and large clearance (≥0.18 mm). Its performance is attributed to the “impact blocking” effect resulting from the synergistic effect of branch channel reflow and multiple vortices; (2) The key-shaped and rectangular structures perform similarly in scenarios involving high-viscosity liquids, low pressure (≤4 MPa), and small clearance (≤0.18 mm), with the key-shaped structure exhibiting better sealing effectiveness; (3) The leakage suppression gain is significantly weakened after the sealing level exceeds 20, and the gap reduction needs to balance the processing cost and reliability; (4) By analogizing the principle of parallel circuits, an optimization scheme is proposed where the width of the branch channels is 0.5 times that of the main channel, and the applicability of this method to high-viscosity laminar flow media is verified (error <5%). This study elucidates the flow mechanism of liquid self-impact sealing, providing a theoretical basis for low-leakage and high-stability sealing designs in high-pressure equipment, and simultaneously expanding the engineering application scenarios of the “impact blocking” concept.

Key words: seal, leakage characteristics, computational fluid dynamics (CFD), turbulence, microscale

摘要：

液体自冲击密封是一种新型非接触式密封技术，具有零磨损、低能耗、长寿命及高稳定性等优势，可满足高压、高速工况下的严苛密封需求。通过数值模拟与多工况分析，系统研究了翼形、矩形及键形悬柱结构的泄漏特性与封严机理，并提出了基于欧姆定律类比的并联流道优化设计方法。研究发现，翼形悬柱结构在低黏液体（如超临界CO₂）、高压（≥4 MPa）、高速（≥11000 r/min）及大间隙（≥0.18 mm）工况下抑漏能力最优，其性能源于支流道回流与多涡旋协同的“冲击阻塞”效应；键形与矩形结构在高黏液体、低压（≤4 MPa）及小间隙（≤0.18 mm）场景中表现相近，而键形封严效果更好；密封级数超过20级后抑漏增益显著减弱，且间隙缩小需权衡加工成本与可靠性；通过类比电路并联原理，提出支流道宽度为主流道0.5倍的优化方案，验证了该方法对高黏层流介质的适用性（误差<5%）。本研究揭示了液体自冲击密封的流动机理，为高压装备的低泄漏、高稳定性密封设计提供了理论依据，同时拓展了“冲击阻塞”理念的工程应用场景。

关键词: 密封, 泄漏特性, 计算流体力学, 湍流, 微尺度