Profile grinding of titanium alloys are now utilized for aero-engine structural components. However, owing to its low thermal conductivity, the grinding contact zone generates an intense deal of heat, resulting in burns on the surface of the workpiece. At the same time, titanium alloys are prone to abrasive adhesion at high temperatures, which aggravates the wear of the grinding wheel. A novel grinding wheel named profile rotating heat pipe-grinding wheel (PRHP-GW) was created to improve heat transfer in the grinding contact zone. Therefore, it is expected to achieve efficient heat exchange. The kind of working medium in the rotating heat pipe (RHP) is the key factor that might seriously influence the heat transmission capacity of the RHP-GW. In this article, the numerical simulation is applied to investigate the heat transfer characteristics of PRHP-GW from the perspective of different grinding heat flux, rotating speed and grinding wheel types (normal grinding wheel without RHP, PRHP-GW filled with deionized water, and PRHP-GW filled with diamond nanofluid). The results demonstrate that the heat transfer capacity of PRHP-GW is superior to that of the normal grinding wheel. In addition, the heat transfer performance of PRHP-GW filled with diamond nanofluid is better than the case filled with deionized water.

An axial rotary heat pipe grinding wheel is a new type of grinding wheel used to strengthen the heat transfer in the grinding arc area. Its heat transfer performance directly affects the heat transfer performance of the entire heat pipe grinding wheel. In this study, the condenser of the heat pipe grinding wheel was designed in conjunction with the condenser design method, and the heat transfer performance of the axial rotating heat pipe grinding wheel condenser was analyzed using a numerical simulation model to optimize the structural parameters of the condenser of the rotating heat pipe grinding wheel. The effects of different fin heights（f=0-8 mm）, nozzle-to-fin top distances（d=3-11 mm）, low-temperature air jet velocities（v j =45-115 m/s）, and grinding wheel speeds（n=150-1 180 r/min） on the heat transfer performance of the condenser were investigated. The results showed that the best heat transfer coefficient of 459 W/（m~2·K） was obtained when the fin height was 6 mm, in which the convective heat transfer coefficient was increased by 36% compared with the finless structure. The best heat transfer performance was obtained when the distance from the nozzle to the top of the fin was 5 mm, and the heat transfer coefficient was 459 W/（m~2·K）. When the low-temperature air jet velocity increases, the convective heat transfer coefficient increases. The highest heat transfer coefficient is achieved at a jet velocity of 115 m/s, up to 459 W/（m~2·K）, which is 43% higher compared to the jet velocity of 45 m/s. When the grinding wheel speed increases, the convective heat transfer coefficient also increases. The highest heat transfer coefficient is achieved at a speed of 1 180 r/min, up to 459 W/（m~2·K）, which is 4% higher than the speed of 150 r/min.

Bone drilling is a common surgical operation, which often causes an increase in bone temperature. A temperature above 47 °C for 60 s is the critical temperature that can be allowed in bone drilling because of thermal bone osteonecrosis. Therefore, thermal management in bone drilling by a rotating heat pipe was proposed in this study. A new rotating heat pipe drill was designed, and its heat transfer mechanism and thermal management performance was investigated at occasions with different input heat flux and rotational speed. Results show that boiling and convection heat transfer occurred in the evaporator and film condensation appears in the condenser. The thermal resistance decreases with the increase of the rotational speed at the range from 1200 to 2000 rpm and it decreases as the input heat flux rises from 5000 to 10,000 W/m2 and increases at 20,000 W/m2. The temperature on the drill tip was found to be 46.9 °C with an input heat flux of 8000 W/m2 and a rotational speed of 2000 rpm. The new designed rotating heat pipe drill showed a good prospect for application to bone drilling operations.

With the rapid development of information science and technology, the demand for computer data processing is increasing, resulting in the rapid growth of the demand for high-power and high-performance solid-state drives (SSDs). The stable operation of SSDs plays an important role in ensuring the reliable working conditions and appropriate temperature of information technology equipment, rack servers, and related facilities. However, SSDs usually have significant heat emissions, putting forward higher requirements for temperature and humidity control, and consequently the heat sink system for cooling is essential to maintain the proper working state of SSDs. In this paper, a new type of thin heat pipe (THP) heat sink is proposed, and the heat transfer performance and cooling effect are experimentally and numerically studied. The numerical results are compared with experimental results, which showed an error within 5%. Single and double heat pipes were investigated under different input powers (from 5 W to 50 W) and different placement angles between 0° and 90°. The heat transfer performance of the new heat sink is analyzed by the startup performance, the evaporator temperature, and the total thermal resistance. The results show that the new double THPs with a 90° angle have a great advantage in the heat transfer performance of SSDs. The research is of great significance for the design and optimization of the SSDs’ cooling system in practical applications.

: The key issue that restricts the development of profile grinding in difficult-to machine materials is usually the thermal damage. Most studies have focused on the cooling efficiency of the coolant; however only few have investigated the heat transfer potency of the grinding wheel matrix. A new cooling method that incorporates a rotating heat pipe (RHP) in the grinding wheel has been proposed. A rotating heat pipe grinding wheel (RHP-GW) is fabricated according to the characteristic of the typical profile surface. The heat transfer performance of the RHP-GW is analyzed for different factors as rotational speed, heat flux and filling ratio by monitoring the internal temperature distribution. Comparative dry grinding of Ti-6Al-4V between a normal grinding wheel (N-GW) and the RHP-GW, a great cooling advantage of the latter one is demonstrated. The workpiece surface quality and the grinding temperature in both the RHP and along the grinding zone are monitored. The energy consumption and CO 2 emission is compared by both coolant cooling and RHP cooling, results show great potency on green machining of heat pipe technology.

To study the matrix strength of the axial rotating heat pipe grinding wheel (HPGW) in the process of high efficiency profile grinding, and considering that HPGW has the characteristics of heat transfer enhancement, ANSYS workbench was used to perform finite element analysis on the HPGW under the thermo-mechanical coupling. At the rotating speed of 30 000 r/min, the maximum equivalent stress of HPGW is 26.481 MPa, and the maximum deformation is 0.014 8 mm, all of which meet the allowable requirements. The influence of rotating speed on maximum equivalent stress and deformation under the conditions of different grinding parameters, matrix materials and workpiece materials was discussed respectively. The results show that at the same feed rate and cutting depth, with the increase of the rotating speed, the maximum equivalent stress of HPGW decreases first and then increases, and the maximum deformation decreases continuously. HPGW with 2Cr13 as the matrix material adopts the creep feed deep grinding process to grind the titanium alloy, which can minimize the stress and deformation. The best parameters in this condition was rotating speed of n=10 000 r/min, workpiece speed of vw=80 mm/min, and cutting depth of ap=0.10 mm.

During profile grinding of fir-tree blade slots, a key issue is usually the excessive heat caused by the complex contact zone. Most studies have focused on the cooling efficiency of the coolant; however only few have investigated the heat transfer potency of the grinding wheel matrix. In this study, a new cooling method that incorporates an axially rotating heat pipe (RHP) in the profile grinding wheel has been proposed. The cooling behavior of the new method was analyzed by both simulation and experimental grinding of titanium alloys. The temperature distributions along the RHP and the workpiece surface were monitored using embedded thermocouples. The effects of input heat flux, filling ratio and rotational speed on heat transfer performance were discussed. Comparative profile grinding experiments among RHP cooling, coolant cooling and no cooling demonstrated a great cooling advantage of RHP cooling with the lowest grinding temperature and better workpiece quality. Considering the research gaps of the previous studies, this work is not only deepens the understanding of the cooling behavior in the RHP during profile grinding of turbine blade slots, but also is helpful to provide guidance on the green machining of industrial products with complex profiles.

This study numerically analyzed the heat transfer characteristics outside the condenser of a rotating heat pipe grinding wheel (RHP-GW).The goal of this investigation is to determine the optimal structure and parameters for the condenser section of RHP-GW.Different fin height (f=0–7 mm),rotational Reynolds number(Re r =1602–6408) and jet Reynolds number (Re j =42 379–108 302) were analyzed under input heat flux of 4000W/m 2 .A fully developed flow was imposed at the outlet of the nozzles.Results showed that the optimal heat transfer rate was obtained for fin height of 5 mm,which improved the average Nusselt number by 84%compared to the structure without fins.A critical Re j for each Re r that the impinging jet can reach the condenser section was found.The critical Re j value increases with Re r ,which is in the range from 42 379 to 61 215 and 61 215 to 80 050for Re r =6408 and Re r =9610,respectively.

Coolants are widely used to dissipate grinding heat in conventional grinding. This process, however, is not satisfactory as coolants often lose efficacy in grinding due to film boiling and can result in adverse health and environment effects. The present paper put forward the concept of a rotating heat pipe grinding wheel, attempting to reduce or eliminate the coolant amount and realize green machining. The heat transfer performance of rotating heat pipe grinding wheel was studied by using volume of fluid method in ANSYS/FLUENT. The influence of the input heat flux, filling ratio and rotational speed were investigated by a simulation method. Results show that the appropriate heat flux range for the rotating heat pipe grinding wheel was from 2000 to 100,000 W/m2, the ideal filling ratio was 50% and the rise of the rotational speed turned out to weaken the heat transfer coefficient. Finally, dry grinding experiments on Ti-6Al-4V were performed and the temperatures in both the rotating heat pipe and the grinding contact zone were monitored. The new designed rotating heat pipe grinding wheel showed a good prospect for application to green grinding of difficult-to-cut materials.