In this study, a previously developed co-simulation method has been expanded to also simulate the dynamic behaviour of sealing gap regions in hydraulic percussion units. This approach is based on a 1D system model representing the fluid components and a 3D finite element model representing the structural parts of a hydraulic hammer. The sealing gap is a fundamental feature of a percussion unit, where the reciprocating motion of the piston is generated by the valve mechanism of the sealing gap. When the gap is closed it will prevent fluid flow between regions of different pressure levels. However, a small leakage flow through the gap will always occur which size depends on the clearance and the position of the piston. The method proposed here will take the structural motion and deformation into consideration when calculating the leakage flow. The deformed state of the structure is approximated by a cylindrical surface, in a least square manner, and communicated through the co-simulation interface to the fluid simulation module, and then used when calculating the leakage flow. This method aims at a more accurate simulation of the leakage flow that will not only yield a more realistic description of the mechanism on the local level, but also a more accurate estimation of global parameters such as overall performance and efficiency. The results indicate that the simulated leakage flow will decrease when dynamic gaps are used in comparison to static gaps, which is a consequence of the deformed structure that will generate smaller clearances. The leakage flow for the dynamic gaps will even be lower than for the static perfectly concentric case, mainly due to the reduction of clearances. The results also indicate that the dynamic eccentricity does not have a major influence on the leakage flow. The outcome from this study highlights the potentials of the described co-simulation approach for analysing the dynamics of the sealing gaps in a hydraulic percussion unit (i.e. gap heights, eccentricity ratios, etc.) including the evaluation of leakage flows and its impact on the overall performance.

在这项研究中，先前开发的共同仿真方法已经扩展到可以模拟液压冲击单元中密封间隙区域的动态行为。该方法基于表示流体成分的1D系统模型和表示液压锤的结构部件的3D有限元模型。密封间隙是冲击单元的基本特征，其中活塞的往复运动是由密封间隙的阀机构产生的。当间隙关闭时，将防止流体在不同压力水平的区域之间流动。但是，始终会出现通过间隙的小泄漏流，其大小取决于间隙和活塞的位置。此处提出的方法在计算泄漏流量时将考虑结构运动和变形。结构的变形状态以最小二乘方的方式由圆柱表面近似，并通过协同仿真接口传递给流体仿真模块，然后在计算泄漏流量时使用。此方法旨在更准确地模拟泄漏流，不仅将在局部级别上更真实地描述该机制，而且还将更准确地估算诸如总体性能和效率之类的全局参数。结果表明，与静态间隙相比，当使用动态间隙时，模拟泄漏流量将减少，这是由于变形的结构将产生较小的间隙而导致的。动态间隙的泄漏流量甚至会比静态完全同心情况下的泄漏流量更低，这主要是由于间隙的减小所致。结果还表明，动态偏心距对泄漏流没有重大影响。这项研究的结果突显了所述共同仿真方法在分析液压冲击单元中密封间隙的动力学（即间隙高度，偏心率等）方面的潜力，包括评估泄漏流量及其对泄漏的影响。整体表现。