摘要:为了研究微磨料浆体射流形成的能量传输与转换,用碳化硅磨料对 40CrMnMo7 钢进行冲击, 建立数学模型描述冲击力与射流压力、喷嘴效率、射流流量、水力功率等参数的相互影响,通过测量射冲击力、射流流量来预测射流系统的单位水力功率的出力状况。 结果表明,该数学模型可以预测射流冲击力与水力功率之比, 由系统压力模型计算的冲击力比实验结果小 20%;在射流的滞止区内,压力与冲击力不呈线性关系,在相同压力下,磨料粒子具有更大的动能,微磨料浆体射流冲击力比纯水射流的大 20%, 单位水力功率提供的射流冲击力随着射流压力的增大而减小;射流冲击力随着喷嘴直径、射流压力的增大而增大,在靶距较小的情况下,冲击力随着靶距的增大而增大,当靶距达到一定值时,冲击力随着靶距的增大而减小。
关键词:射流冲击力; 射流压力; 射流流量; 喷嘴效率; 水力能量
Abstract:To discuss the energy transmission and transformation efficiency during the formation of micro-abrasive slurry jet,the 40CrMnMo7 steel was impacted by the cerium oxide abrasive impinge. A mathematical model about the relation of impact force with jet pressure, flow rate, nozzle efficiency and hydraulic power was developed. By measuring jet impact force and jet rate,the output condition of unit hydraulic power in jet system could be predicted. The results show that the mathematical model can predict the ratio between impact force and hydraulic power. The impact force calculated by the system pressure model is 20% less than the experiment values. In the jet stagnation zone,the increase of impact and pressure is not linear. The impact force of the micro-abrasive slurry jet is about 20% larger than the impact force of pure slurry jet. It is because that the abrasive particles have larger kinetic energy at the same pressure. With the increase of jet pressure, the jet impact force provided by unit hydraulic power decreases. With the increase of the nozzle diameter and pressure, the jet impact force increases. When the target distance is relatively small,the impact force increases with the increasing of target distance. But the force decreases with the target distance increase when the target distance reaches a certain value.
Keywords:impact force;jet pressure;flow rate;nozzle efficiency;hydraulic energy