潜孔冲击器非线性动力学建模

潜孔冲击器在工作过程中，气源压力进入工具中驱动活塞做高频高速的轴向往复运动，并冲击钎头使其进行破岩钻进。首先，以无缸潜孔冲击器为例，结合其结构特点分析工作原理；其次，基于计算流体力学、热力学和应力波传递相关理论，考虑气体的压力、温度和密度的变化，分别建立了气室气体的瞬变流模型、绝热模型以及活塞的冲击回弹模型；然后，基于活塞的运动状态和气室气体状态，将潜孔冲击器1个运动周期分为11个不同阶段，结合上述3个模型和活塞的运动学方程，建立了完整的潜孔冲击器的非线性动力学模型；最后，基于该模型对实际算例进行计算。结果表明，活塞运动参数、气室压力数值变化与潜孔冲击器的工作原理与运动学规律一致。对潜孔冲击器的设计与研发提供研究基础与方法，为相关工具的动力学模型和仿真模型的建立提供参考。

Nonlinear Dynamics Modeling of Down-the-hole Hammer

The nonlinear Dynamics and fluid-solid coupling simulation of down-the-hole (DTH) hammer are studied. First of all, taking the cylinder-less down-the-hole (DTH) hammer as an example, the working principle of the DTH hammer is analyzed according to structure characteristics. Then, taking into account the effects of changes in pressure, temperature and density of the gas, based on the theories of fluid mechanics, computational fluid dynamics, impact dynamics, etc., the transient flow model, adiabatic model of the gas chamber and the impact-rebound model of the piston and the bit are established. The complete nonlinear dynamic model is established by combining the piston and gas chamber states in 11 stages of DTH hammer. Based on the nonlinear dynamic model, the calculation is carried out for a practical example. The results show that the movement parameters of the piston and the numerical changes of the air chamber pressure are consistent with the working principle and kinematics of the DTH hammer. It provides the research basis and method for the design and development of DTH impactor, and provides a reference for the establishment of dynamic model and simulation model of related tools.