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Abstract：
The high-frequency pulse flow, equivalent to the natural frequency of rocks, is generated by a self-excited oscillating cavity to achieve resonance rock-breaking. The flow field and oscillating mechanism of the self-excited oscillating cavity were simulated using the large eddy simulation method of Computational Fluid Dynamics (CFD). A field-scale testing apparatus was developed to investigate the impulse characteristics and verify the simulation results. The results show that the fluid at the outlet at the tool is deflected due to the pulse oscillation of the fluid. The size and shape of low-pressure vortices constantly change, leading to periodic changes in fluid impedance within the oscillating cavity. The impulse frequency reaches its highest point when the length-diameter ratio is 0.67. As the length-diameter ratio increases, the tool pressure loss also increases. Regarding the cavity thickness, the impulse frequency of the oscillating cavity initially decreases, then increases, and finally decreases again. Moreover, both the impulse frequency and pressure loss increase with an increase in displacement. The numerical simulation findings align with the experimental results, thus confirming the validity of the theoretical model. This research provides theoretical guidance for the practical application of resonance rock-breaking technology.
摘要：
高频脉冲流，相当于岩石的固有频率，由自激振荡腔产生，实现共振破岩。利用计算流体动力学(CFD)的大涡模拟方法,对自激振荡腔的流场和振荡机理进行了模拟。开发了一种现场规模的测试设备来研究脉冲特性并验证仿真结果。结果表明，由于流体的脉冲振荡，工具出口处的流体发生偏转。低压涡流的大小和形状不断变化，导致振荡腔内流体阻抗的周期性变化。当长径比为0.67时，脉冲频率达到最高点。随着长径比的增加，工具压力损失也增加。关于空腔厚度，振荡腔的脉冲频率最初降低，然后增加，最后又减少了。此外，脉冲频率和压力损失都随着位移的增加而增加。数值模拟结果与实验结果一致，从而证实了理论模型的有效性。该研究为共振破岩技术的实际应用提供了理论指导。
