Investigation of heat pipe drilling application

It's widely known that hole making is, by a significant margin, the most frequently performed process among metalworking operations. It's also among the most difficult operations to control from a thermal perspective. The most common cooling method is the use of cutting fluids flooding through the cutting zone. However, disposal of the used fluids is subject to federal, state and local laws and regulations. More stringent regulations in environmental pollution are expected in the future, we can expect the cost associated with coolants to continue to rise. Experimental studies implementing the use of a heat pipe to cool the drill and thus reduce the amount of cutting fluid required have been recently conducted. The heat pipe works with no moving parts or electronics and it also offers an effective alternative to removing heat without significant increases in operating temperatures. The operating mechanism of heat pipes have been extensively studied, however, rotating heat pipes with a wick structure has not received adequate attention in the past. In this study, a numerical analysis has been conducted to model the flow in an axially rotating heat pipe. The result shows the transport capacity is strongly affected by changes in the thermal physical properties of the working fluid with the temperature. The rotating speeds have strong effect in the vapor core but this effect is weak in the liquid flow of the wick structure.