中文摘要：

脉冲射流具有流体脉动特性，应用在钻井作业中，能起到较常规射流更为明显的辅助破碎岩石和清洗井底岩屑的作用。运用计算流体动力学技术，采用雷诺平均Navier-Stokes方程和K-ε湍流模型，对装有脉冲喷嘴的PDC钻头进行井底流场数值模拟，分析脉冲射流压力波动变化、脉冲射流辅助破碎井底岩石性能以及在PDC刀翼上流体湍流运动的力学性质和脉动情况。模拟结果表明，脉冲射流作用于PDC钻头，能够在一定程度上增强射流辅助破碎岩石、井底岩屑运移和PDC切屑齿的清洗、冷却效果。该项研究成果可为装有自激励振荡脉冲喷嘴的全尺寸PDC钻头进行井底流场的水力特性室内及现场试验提供一定的参考。

英文摘要：

Pulsed jet is characterized by fluid pulsation. When it is used in drilling, it has more obvious effect in auxiliary crushing of rock and cleaning bottomhole cuttings than conventional jet. Applying computational fluid dynamic technology and adopting the Reynolds averaged Navier Stokes equation anti K-ε turbulence model, the bot- tomhole flow field numerical simulation of PDC bit provided with pulsed nozzle was conducted. The pressure fluctua- tion of pulsed jet, the auxiliary bottomhole rock crushing performance of pulsed jet and the mechanical property and pulsation of fluid turbulence movement on PDC blade were analyzed. The simulation shows that pulsed jet aets on PDC bit and it can improve the auxiliary rock crushing effect of the jet, strengthening the effects of bottomhole cut- tings migration and the cleaning anti cooling of PDC cutter.