Simulation and Experimental Research on Flow Field and Temperature Field of Diamond Impregnated Drill Bit

Impregnated diamond bits (IDB) are one of the main rotary drilling tools used for hard rock drilling. In the process of using IDB to drill, the friction and heat generation with the rock formation are important factors which will affect the drilling efficiency. These two factors may reduce the technical and economic indicators of drilling and cause “burning” accidents. In order to improve the drilling efficiency of the diamond bit, the bit structure was reasonably designed to ensure that the bit had a good cooling and chip removal ability during the drilling process. The bottom flow field and temperature field of IDB were investigated by combining numerical simulation with experimental study. The results showed that, for the IDB with 4 water ways, on the side of the water way with the same rotating direction of the bit, the velocity was faster, and the maximum velocity reached 23.65 m/s. At the contact surface between the bit and rock, the temperature reached the highest level of 210 ℃ and dropped rapidly from bottom to top until it was close to the temperature of the flushing fluid. The increase of the number of water ways led to a small flow rate of drilling fluid at a single water way, which reduced the heat conduction efficiency and resulted in poor cooling effect and serious bit wear.