文档介绍：Abstract
People pay more and more attention to high performance water jet. For example, various additives were added into jet that can improve the capacity of cutting and erosion. Taking pulsed water-gas nozzles as research object, based on self-excited oscillation pulsed jet, the pulsed water-gas jet has been formed by entraining and mixing the air in the self-oscillating pulsed jet that can improve the affect of oscillation and the capacity of rock breaking. Mathematics model of disturbance wave propagation in oscillation chamber was established by using continuity equation and momentum equation. The cantilever beam was adopted as erosion -ZSA1 Vibration Analyzer was used to test vibration of the cantilever beam which was impacted by the pulsed water-gas jet, and dynamic characteristics of pulsed water-gas jet is obtained. Compared with pulsed jet, the frequency characteristic of pulsed water-air jet es plicated, and the main pulsed frequency move to the left. By analyzing the spectrum graph, the variation rule of frequency versus the pump pressure or cavity length can be obtained. In addition, the erosion performance of pulsed water-air jet and pulsed jet were verified by the use of concrete, pressive strength of which is . The results indicated that the erosive effect of pulsed water-air jet is superior to that of the pulsed jet, the maximal erosive volume of the former is significantly higher than that of latter (22%), but the erosion depth between them shows little change. The erosive volume of the pulsed water-air jet increase with the volumetric flux of the injected air, eventually reaching a maximum value, and then decreasing slightly, namely there exists an optimum air-flow rate. However, the air flow rate has slight effect on the erosion depth.
Key words: pulsed water-gas jet, pulsed water jet, frequency characteristics, erosion
目录
摘要......................................................................................................