Heat Transport Capacity of an Axial-Rotating Single-Loop Oscillating Heat Pipe for Abrasive-Milling Tools

Abstract

In order to enhance heat transfer in the abrasive-milling processes to reduce thermal damage, the concept of employing oscillating heat pipes (OHPs) in an abrasive-milling tool is proposed. A single-loop OHP (SLOHP) is positioned on the plane parallel to the rotational axis of the tool. In this case, centrifugal accelerations do not segregate the fluid between the evaporator and condenser. The experimental investigation is conducted to study the effects of centrifugal acceleration (0–738 m/s2), heat flux (9100–31,850 W/m2) and working fluids (methanol, acetone and water) on the thermal performance. Results show that the centrifugal acceleration has a positive influence on the thermal performance of the axial-rotating SLOHP when filled with acetone or methanol. As for water, with the increase of centrifugal acceleration, the heat transfer performance first increases and then decreases. The thermal performance enhances for higher heat flux rises for all the fluids. The flow inside the axial-rotating SLOHP is analyzed by a slow-motion visualization supported by the theoretical analysis. Based on the theoretical analysis, the rotation will increase the resistance for the vapor to penetrate through the liquid slugs to form an annular flow, which is verified by the visualization.

Numerical Analysis on Temperature Field of Grinding Ti-6Al-4V Titanium Alloy by Oscillating Heat Pipe Grinding Wheel

“…Additionally, the oscillating heat pipes are positioned on the plane parallel to the rotational axis of the grinding wheel. In this case, centrifugal acceleration caused by the rotation does not segregate the fluid between the evaporator and condenser, and the rotation benefits the improvement of the heat transfer [51][52][53][54][55]. The oscillating heat pipe channels are formed by several straight holes along the axis direction and connected grooves, as shown in Figure 1.…”

“…Besides, the evaporator and condenser of the OHP are both 20 mm long. According to the thermal performance studies of single-loop closed OHPs, acetone is chosen as the working fluid for its good heat transport capacity [43,49,50,55]. In the condenser region of the OHP grinding wheel, eight fins are used for the enhancement of heat transfer.…”

“…In this simulation, the equivalent thermal conduction of the OHP is determined as follows: The properties of the workpiece and grinding wheel materials are summed up in Table 1. The oscillating heat pipes inside the OHP grinding wheel are filled with acetone and have a maximum effective heat transfer coefficient of 2699 W/(m 2 •K) [43,50,55]. In this simulation, the equivalent thermal conduction of the OHP is determined as follows:…”

Heat transfer performance and prediction of open pulsating heat pipe for self-cooling cutting tool

“…For example, Wu et al [5,6] combined the open PHP with the turning tool insert or holder, which reduced the cutting temperature of the tool nose by about 10% and improved the cutting life of the tool by about 20-30%. Qian et al [7,8] positioned multiple singleloop closed PHPs in grinding wheels and abrasive-milling tools. The results of this study represented that the cooling effect of the PHP in the grinding and milling process was better than that of the coolant.…”

Thermal Systems—An Overview

“…Qian et al [4] propose the application of oscillating heat pipes to reduce thermal damage in an abrasive milling tool. Heat pipes are passive heat transfer devices with excellent heat transport capacity and they are applied to the machining process to enhance heat transfer.…”