An Investigation of Heat Dissipation in High Speed Machining

2009 ◽  
Vol 69-70 ◽  
pp. 480-484 ◽  
Author(s):  
Yan Ming Quan ◽  
Joseph A. Arsecularatne ◽  
Liang Chi Zhang
Keyword(s):  
Heat Transfer ◽  
Surface Integrity ◽  
Temperature Rise ◽  
Material Removal ◽  
High Speed ◽  
Heat Dissipation ◽  
High Speed Machining ◽  
Heat Transfer Medium ◽  
Quantitative Understanding ◽  
Bar Turning

High speed machining (HSM) is finding wider applications due to its economic advantages, such as faster material removal rates, and its technological merits, such as improved surface finish. Nevertheless, the application of HSM also brings about some undesirable results. For example, the tool life and surface integrity of a machined component are greatly affected by the large amount of heat generated, but heat dissipation during an HSM has not been well understood. This paper aims to achieve a quantitative understanding of the heat dissipation in HSM using a bar turning configuration. Based on the calorimetric method and utilizing water as the heat transfer medium, the temperature rise in water was measured to determine the fractions of heat dissipated into the chips, the tool and the workpiece during machining. The obtained results show that the chips take the largest portion of the heat generated and this fraction increases with the increase in feed.

Surface Integrity In High Speed Machining Of Alloy

2007 ◽  
pp. 87-95 ◽  
Author(s):  
J.D. Puerta Velásquez ◽  
B. Bolle ◽  
P. Chevrier ◽  
A. Tidu
Keyword(s):  
Surface Integrity ◽  
High Speed ◽  
High Speed Machining

scholarly journals Heat Transfer and Its Innovative Applications

Inventions ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 4
Author(s):  
Ping-Hei Chen ◽  
Hyung Cho
Keyword(s):  
Heat Transfer ◽  
Artificial Intelligence ◽  
High Speed ◽  
Heat Dissipation ◽  
Outer Space ◽  
Electronic Devices ◽  
Daily Lives ◽  
Autonomous Cars

Innovative and high-end techniques have been recently developed in academic institutes and are gradually being employed in our daily lives for improving living quality, namely, artificial intelligence (AI) technology, autonomous cars, hyper-loop for high-speed transportation, miniaturization of electronic devices, heat dissipation from cooling films to outer space, and so on [...]

Thermal Analysis and Test for a High Speed PM Machine for Fan Application

2011 ◽  
Vol 383-390 ◽  
pp. 4727-4734 ◽  
Author(s):  
Ji Qiang Wang ◽  
Feng Xiang Wang
Keyword(s):  
Thermal Analysis ◽  
Temperature Rise ◽  
Power Loss ◽  
High Speed ◽  
Heat Dissipation ◽  
Machine Design ◽  
Test Results ◽  
Power Losses ◽  
Running Speed ◽  
High Speed Machine

For a give air flux, the higher speed the fanner is running, the smaller the fanner’s size is. It is also well known that for a given power, the higher the machine’s running speed, the smaller the machine’s size has. If the fanner is geared to a high speed machine directly, the fan set’s volume will be sharply decreased. However, the heat dissipation of the high speed machine becomes a serious problem also due to the small size and high power loss density. Therefore, how to estimate accurately the power losses and temperature rise is a key issue for the high speed machine design. In this paper, the power losses and temperature of high speed PM machine for a fanner application are thoroughly investigated. And the test results of a prototype fan set partly shown the validity of the calculation method.

Reduction of Vibrations due to Unbalance with Anti-Vibration Clearance Angle in High Speed Milling

2016 ◽  
Vol 836-837 ◽  
pp. 161-167
Author(s):  
Anna Thouvenin ◽  
Xin Li ◽  
Ning He ◽  
Liang Li
Keyword(s):  
Material Removal ◽  
High Speed ◽  
Removal Rate ◽  
Machining Process ◽  
High Speed Machining ◽  
Machining Processes ◽  
High Speed Milling ◽  
Clearance Angle ◽  
Fast Solution ◽  
Considerable Problem

High speed milling is one of the most commonly used machining processes in many fields of the industry. It is regarded as a simple and fast solution to achieve a high material removal rate, which allows an important production of parts. Unbalance is a problem in any machining process but becomes a considerable problem when reaching high speed machining. The vibrations due to an unbalanced tool or tool holder can result in a poor surface quality and a damaged tool. The damping of the vibrations can be achieved with a specially designed tool showing an anti-vibration clearance angle. This paper shows the influence of the anti-vibration clearance angle by a computational model and a set of experiments to see if it can reduce or suppress the vibrations due to unbalance in high speed milling.

Experiments and Modeling of a Liquid Droplet Transported by a Gas Stream Impinging on a Heated Surface: Evaporative Regime

2009 ◽  
Author(s):  
Ryan P. Anderson ◽  
Alfonso Ortega
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Single Phase ◽  
Heat Dissipation ◽  
Liquid Droplet ◽  
Heated Surface ◽  
Thin Liquid Film ◽  
Spray Cooling ◽  
High Speed Photography ◽  
Transfer Coefficients

Understanding the transport mechanisms involved in a single droplet impinging on a heated surface is imperative to the complete understanding of droplet and spray cooling. Evidence in the literature suggests that gas assisted sprays and mist flows are more efficient than sprays consisting only of liquid droplets. There has been few if any fundamental studies on gas-assisted droplets or spray cooling, in which a carrier gas or vapor stream propels the droplet to the target surface. The current work extends previous studies of a droplet impinging on a heated surface conducted by the same group from the single phase regime into the evaporative regime. For both regimes, understanding the transport physics due to the heat transfer from the heated surface to the droplet and then by convection and evaporation to the airflow is of fundamental importance. High-speed photography was used to capture the spreading process and yielded results that correlated well with previously published isothermal and single-phase results. The heat transfer was measured with a fitting approach by which the instantaneous temperature profile was matched to an analytic solution to determine the instantaneous value of the centerline heat transfer coefficient. A very large increase in the heat dissipation was observed when compared to previously published single-phase results. Heat transfer was optimized at Reynolds numbers that produced an optimally thin liquid film and high heat and mass transfer coefficients on the surface of the film.

Analysis and Experimental Research on the Fluid–Solid Coupled Heat Transfer of High-Speed Motorized Spindle Bearing Under Oil–Air Lubrication

2020 ◽  
Vol 143 (7) ◽  
Author(s):  
Feng Gao ◽  
Weitao Jia ◽  
Yan Li ◽  
Dongya Zhang ◽  
Zhengliang Wang
Keyword(s):  
Heat Transfer ◽  
Temperature Rise ◽  
High Speed ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Phase Flow ◽  
Motorized Spindle ◽  
Two Phase ◽  
Spindle Bearing ◽  
Air Lubrication

Abstract For high-speed motorized spindle bearing, temperature rise is the primary factor that restricts the maximum speed of spindle and affects the stability of system. This paper addresses the lubrication and cooling of spindle bearing by exploiting the precise oil control and high cooling efficiency of oil–air lubrication. Enlightened by the bearing tribology and two-phase flow theory, a numerical model of oil–air two-phase flow heat transfer inside bearing cavity is created, with which the effects of operating condition and nozzle structure parameters on the temperature rise are studied. As the results show, with the elevation in speed, the heat generation increases rapidly, and despite the somewhat enhanced heat transfer effect, the temperature still tends to rise. Given the higher volume fraction of air than oil in the two-phase flow, the temperature rise of bearing is suppressed greatly as the air inlet velocity increases, revealing a remarkable cooling effect. When a single nozzle is used, the bearing temperature increases from the inlet to both sides, which peaks on the opposite side of the inlet. In case multiple evenly distributed nozzles are used, the high-temperature range narrows gradually, and the temperature distributions in the inner and outer rings tend to be consistent. With the increase in the nozzle aspect ratio, the airflow velocity drops evidently, which affects the heat dissipation, thereby resulting in an aggravated temperature rise. Finally, the simulation analysis is verified through experimentation, which provides a theoretical basis for selecting optimal parameters for the oil–air lubrication of high-speed bearing.

scholarly journals Towards Optimization of Surface Roughness and Productivity Aspects during High-Speed Machining of Ti–6Al–4V

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3749 ◽  
Author(s):  
Adel T. Abbas ◽  
Neeraj Sharma ◽  
Saqib Anwar ◽  
Faraz H. Hashmi ◽  
Muhammad Jamil ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Titanium Alloys ◽  
Material Removal Rate ◽  
Material Removal ◽  
High Speed ◽  
Removal Rate ◽  
Depth Of Cut ◽  
Optimization Approach ◽  
High Speed Machining

Nowadays, titanium alloys are achieving a significant interest in the field of aerospace, biomedical, automobile industries especially due to their extremely high strength to weight ratio, corrosive resistance, and ability to withstand higher temperatures. However, titanium alloys are well known for their higher chemical reactive and low thermal conductive nature which, in turn, makes it more difficult to machine especially at high cutting speeds. Hence, optimization of high-speed machining responses of Ti–6Al–4V has been investigated in the present study using a hybrid approach of multi-objective optimization based on ratio analysis (MOORA) integrated with regression and particle swarm approach (PSO). This optimization approach is employed to offer a balance between achieving better surface quality with maintaining an acceptable material removal rate level. The position of global best suggested by the hybrid optimization approach was: Cutting speed 194 m/min, depth of cut of 0.1 mm, feed rate of 0.15 mm/rev, and cutting length of 120 mm. It should be stated that this solution strikes a balance between achieving lower surface roughness in terms of Ra and Rq, with reaching the highest possible material removal rate. Finally, an investigation of the tool wear mechanisms for three studied cases (i.e., surface roughness based, productivity-based, optimized case) is presented to discuss the effectiveness of each scenario from the tool wear perspective.

Surface Integrity in High Speed Machining of TI-6WT.%AL-4WT.%V Alloy

2008 ◽  
pp. 1319-1320 ◽  
Author(s):  
Juan David Puerta Velasquez ◽  
Bernard Bolle ◽  
Pierre Chevrier ◽  
Albert Tidu
Keyword(s):  
Surface Integrity ◽  
High Speed ◽  
High Speed Machining

scholarly journals Results of the experimental research of the heat-transfer jet pressure to the rock surface during thermal reaming of the borehole

2018 ◽  
Vol 60 ◽  
pp. 00024 ◽  
Author(s):  
Oleksii Voloshyn ◽  
Iryna Potapchuk ◽  
Oleksandr Zhevzhyk ◽  
Mykola Zhovtonoha
Keyword(s):  
Heat Transfer ◽  
Experimental Research ◽  
Lateral Surface ◽  
High Speed ◽  
Rock Surface ◽  
Heat Transfer Medium ◽  
Thermal Methods ◽  
Capacity Coefficient ◽  
Heating Capacity ◽  
Number Of Publications

The performed analysis of scientific sources confirms the existence of a small number of publications devoted to the experimental research of the gasdynamics and plasmodynamics of jets used as a heat-transfer medium in the thermal methods of mine rocks destruction. There are almost no experimental and theoretical publications related to the multiple-jet plasmotrons research. The expediency of own experimental researches performing has been substantiated concerning the lateral inflow of heat-transfer medium high-speed jets on the borehole surface. An experimental research has been made of the interaction between the heat-transfer medium high-speed jets and the surface of the borehole imitated by the through duct. The further prospects of this work are the following: to determine the gas velocity along the lateral surface of the through duct and the value of the heating capacity coefficient from the heat-transfer medium to the lateral surface of the through duct, which imitates the rock surface in the borehole. These parameters are required for creating a mathematical model of the brittle destruction of rocks.

Experimental Study on High Speed Machining of a Titanium Alloy

2009 ◽  
Vol 69-70 ◽  
pp. 451-455
Author(s):  
Guo Sheng Geng ◽  
Jiu Hua Xu
Keyword(s):  
Titanium Alloy ◽  
Tool Life ◽  
Surface Integrity ◽  
High Speed ◽  
Cutting Speed ◽  
Fatigue Property ◽  
High Speed Machining ◽  
Ta15 Titanium Alloy ◽  
Milling Tool ◽  
Speed Range

High Speed Machining (HSM) has been proved to be useful in the machining of many materials. This research is concerned with the performance of HSM in the milling of Ti-6.5Al-2Zr-1Mo-1V (TA15) titanium alloy. The tool life and wear mechanism of the milling tool under different cutting speed were investigated, and the influences of cutting speed on the surface integrity and fatigue property of the machined part were studied. According to the experimental results, acceptable tool life can be obtained in a speed range up to 200m/min. The results also show that increasing cutting speed can help to improve the surface integrity and fatigue property of the machined part.

Sign in / Sign up

Export Citation Format

Share Document