Prediction of the Hardened Layer in Traverse Cylindrical Grinding-Hardening

2011 ◽  
Vol 697-698 ◽  
pp. 13-18 ◽  
Author(s):  
Thai Nguyen ◽  
Liang Chi Zhang
Keyword(s):  
Heat Transfer ◽  
Hardened Layer ◽  
Annealing Process ◽  
Grinding Wheel ◽  
Transfer Model ◽  
Moving Heat Source ◽  
Workpiece Material ◽  
Cylindrical Grinding ◽  
Grinding Hardening ◽  
Good Agreement

A finite element heat transfer model incorporating a moving heat source has been developed to predict the temperature field in traverse cylindrical grinding. The model was then applied to analyse the grinding-hardening of quenchable steel 1045. It was found that in the region where the grinding wheel had an entire contact with the workpiece, material would experience a heating-cooling cycle, enabling the generation of a uniform hardened layer. In the transient regions at the two ends of the workpiece where the wheel-workpiece contacts were partial, the material was not hardened but experienced an annealing process. The results were in good agreement with the experimental observations.

Heat Transfer in Grinding-Hardening of a Cylindrical Component

2011 ◽  
Vol 325 ◽  
pp. 35-41 ◽  
Author(s):  
Thai Nguyen ◽  
Liang Chi Zhang ◽  
Da Le Sun
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Hardened Layer ◽  
Transfer Model ◽  
Plunge Grinding ◽  
Cylindrical Component ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Grinding Hardening ◽  
Good Agreement

A three-dimensional finite element heat transfer model incorporating a moving heat source was developed to investigate the heat transfer mechanism in grinding-hardening of a cylindrical component. The model was applied to analyze the grinding-hardening of quenchable steel 1045 by two grinding methods, traverse and plunge grinding. It was found that the heat generated can promote the martensitic phase transformation in the ground workpiece. As a result, a hardened layer with a uniform thickness can be produced by traverse grinding. However, the layer thickness generated by plunge grinding varies circumferentially. The results are in good agreement with the experimental observations.

An Investigation of the Grinding-Hardening Induced by Traverse Cylindrical Grinding

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Thai Nguyen ◽  
Mei Liu ◽  
Liangchi Zhang ◽  
Qiong Wu ◽  
Dale Sun
Keyword(s):  
Heat Transfer ◽  
Base Material ◽  
Hardened Layer ◽  
Transfer Model ◽  
Molten Material ◽  
Grinding Method ◽  
Small Pitch ◽  
Cylindrical Workpiece ◽  
Grinding Hardening ◽  
Traverse Grinding

This study investigates the formation of the layer hardened on a cylindrical workpiece by grinding-hardening using the traverse grinding method. A finite element heat transfer model, that took into account the helical trajectory of the of the grinding heat source movement, was developed. The hardened layer was found featuring a wavy profile as a result of the heat conduction from an adiabatic plane crossing the middle of the trajectory pitch. The accumulation of the grinding heat within a small pitch can lead to the welding of the molten material with the base material. Enlarging the pitch by reducing the workpiece speed will increase the time of heating, allowing the heat to penetrate deeper and to expand wider in the workpiece, thus thickening the hardened layer.

Influence of Grinding Parameters on the Depth and Uniformity of Cylindrical Grinding-Hardened Layer

2010 ◽  
Vol 102-104 ◽  
pp. 733-737
Author(s):  
Ju Dong Liu ◽  
Jie Zhen Zhuang ◽  
Xi Lin Zhang ◽  
Zhi Long Xu
Keyword(s):  
Hardened Layer ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Feed Speed ◽  
Practical Application ◽  
Cylindrical Grinding ◽  
Grinding Parameters ◽  
Grinding Hardening ◽  
Surface Hardened Layer

On the basis of the cylindrical grinding-hardening test, the influences of the grinding parameters on surface hardened layer were studied. The result shows that when ap≤0.2mm, there is an unhardened area exist in cylindrical grinding hardened workpiece. When ap＞0.2mm, there is a tempered area exist in cylindrical grinding hardened workpiece due to the action of grinding heat during cut-in and cut-out of grinding wheel. When depth of cut increases, or feed speed decreases, the hardened layer depth increases accordingly. In the practical application, the satisfactory quality of the cylindrical grinding hardened layer can be obtained through reasonable combination of ap and vw.

Heat Transfer Model and Analysis of Oil-Immersed Electrical Transformers with Heat Pipe Radiator

2012 ◽  
Vol 516-517 ◽  
pp. 312-315
Author(s):  
Guang Hua Li ◽  
Hong Lei Liu ◽  
De Jian Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Temperature Field ◽  
Heat Pipe ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Cooling Device ◽  
Transformer Design ◽  
Electrical Transformers ◽  
Good Agreement

This paper has formulated a heat transfer model for analyzing the cooling properties of a heat pipe cooling device of oil-immersed electrical transformer. Based on the model, the oil temperature field of a 30 KVA oil-immersed transformer has been numerical simulated, and experiments also had been conducted. Results showed that the numerical simulation has good agreement with experiment results. Results also showed that heat pipe radiator is feasible for oil-immersed electrical transformer cooling. The model can be used to analyze the oil temperature distribution properties in an oil-immersed electrical transformer with heat pipe cooling device, and provide theoretical guide for transformer design and improvement.

Heat Transfer Modeling of Nanoparticle Packings on a Substrate

2018 ◽  
Author(s):  
Anil Yuksel ◽  
Edward T. Yu ◽  
Michael Cullinan ◽  
Jayathi Murthy
Keyword(s):  
Heat Transfer ◽  
Laser Power ◽  
Thermal Conductance ◽  
Heat Transfer Model ◽  
Experimental Result ◽  
Transfer Model ◽  
Heat Transfer Modeling ◽  
Interfacial Thermal Conductance ◽  
High Laser ◽  
Good Agreement

The temperature evolution of nanoparticle packings on a substrate under high laser power is investigated both experimentally and via numerical simulations. Numerical modeling of temperature distributions in copper nanoparticle packings on a glass substrate is performed and results are compared with experiment under 2.6 kW/cm2 laser power. A coupled electromagnetic-heat transfer model is implemented to understand the nanoparticle temperature distribution. Very good agreement between the coupled electromagnetic-heat transfer model and the experimental results is obtained by matching the interfacial thermal conductance, G, between the nanoparticles using the experimental result in the coupled electromagnetic-heat transfer model.

Analytical Model for Heat Transfer Phenomena in Cup-Cast Method

2006 ◽  
Vol 116-117 ◽  
pp. 569-572
Author(s):  
Farshid Pahlevani ◽  
J. Yaokawa ◽  
M. Itamura ◽  
M. Kikuchi ◽  
O. Nagasawa ◽  
...  
Keyword(s):  
Heat Transfer ◽  
A356 Alloy ◽  
Nucleation And Growth ◽  
Heat Transfer Model ◽  
Solid Particles ◽  
Transfer Model ◽  
Heat Transfer Phenomenon ◽  
Semi Solid ◽  
Slurry Preparation ◽  
Good Agreement

Cup-cast method is a new method deals with semi-solid slurry preparation recently developed by the authors. In this method, suspension of globular solid particles in molten metal is prepared by controlling the nucleation and growth of solid-particles through the simplest and quickest techniques. In this method, heat transfer phenomenon plays an important role in governing the shape, size, and fraction of solid particles. In the current study, a heat transfer model was proposed and applied to Al-A356 alloy semi-solid slurry preparation. The heat transfer model was based on heat balance consideration between cup and slurry and it was in a good agreement with experimental results.

A Heat Transfer Model of Grinding Process Based on Energy Partition Analysis and Grinding Fluid Cooling Application

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Guoxu Yin ◽  
Ioan D. Marinescu
Keyword(s):  
Heat Transfer ◽  
Contact Area ◽  
Frictional Resistance ◽  
Heat Transfer Model ◽  
Heat Energy ◽  
Grinding Wheel ◽  
Transfer Model ◽  
Grinding Process ◽  
Energy Partition ◽  
Grinding Fluid

In the grinding process, high temperature in grinding area is generated by the frictional resistance between workpiece and abrasive grains on the grinding wheel cylindrical surface. Grinding fluid application is an optimal option to reduce the thermal effect and crack on the workpiece ground surface. In this paper, a grinding process heat transfer model with various grinding fluid application is introduced based on computational fluid dynamics (CFD) methodology. The effect of specific heat, viscosity, and surface tension of grinding fluid are taken into account. In the model, the grinding contact area is considered as a heating resource. Most of the heat energy is conducted into the workpiece. The rest of the energy is taken away by the grinding wheel, grinding fluid, and chips. How many percentage of the generated heat is conducted into the workpiece is a key issue, namely, the energy partition ratio ε. An energy partition equation is introduced in this paper with the cooling effect of different grinding fluid. Generated heat energy based on the calculation from energy partition equation is applied on the grinding contact area in the heat transfer model.

scholarly journals A two-stage heat transfer model for the peripheral layers of a grain store

2003 ◽  
Vol 7 (3) ◽  
pp. 147-164
Author(s):  
Alexsandar Antic ◽  
James M. Hill
Keyword(s):  
Heat Transfer ◽  
Present Model ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Two Stage ◽  
Peripheral Layer ◽  
Proposed Model ◽  
Grain Bulk ◽  
Insight Into ◽  
Good Agreement

An understanding of the flow of heat in grain store structures, in particular, within the peripheral layer, is important from many industrial perspectives. To analyse the heat transfer within such regions a mathematical model known as the two-stage heat transfer model is proposed. This model makes a distinction between the air and grain within the grain bulk, and thus takes into consideration the fact that the rate of heat transfer through the grain is different to that through the interstitial air surrounding the grain. Such a model lends itself to a solution via Laplace transforms and approximate analytical results are obtained for small and large times. In addition, the Stehfest numerical algorithm is used for the inversions and very good agreement is obtained between the two approaches. The present model is compared to a previously developed double-diffusivity heat transfer model by the authors, and good agreement is obtained. At present, no experimental data is available to validate the model as it is very difficult to measure the air and grain temperatures separately, particularly in the peripheral layer. The proposed model provides insight into the potential difference existing between the air and grain temperatures.

A one dimensional heat transfer model for wolverine (gulo-gulo) hair

2018 ◽  
Vol 30 (4) ◽  
pp. 548-558
Author(s):  
HongYan Liu ◽  
Addie Bahi ◽  
Frank K. Ko
Keyword(s):  
Heat Transfer ◽  
Cold Weather ◽  
Transfer Model ◽  
Counting Method ◽  
Content Type ◽  
Box Counting ◽  
Proposed Model ◽  
Extreme Cold ◽  
Box Counting Method ◽  
Good Agreement

Purpose Wolverine hairs with superior heat transfer properties have been used as fur ruffs for extreme cold-weather clothing. In order to understand the exclusive mechanism of wolverine surviving in the cold areas of circumpolar, the purpose of this paper is to establish a one-dimensional fractional heat transfer equation to reveal the hidden mechanism for the hairs, and also calculate the fractal dimension of the wolverine hair using the box counting method to verify the proposed theory. The observed results (from the proposed model) found to be in good agreement with the box counting method. This model can explain the phenomenon which offers the theoretical foundation for the design of extreme cold weather clothing. Design/methodology/approach The authors calculated the fractal dimension of the wolverine hair using the box counting method to verify the proposed theory. The observed results (from the proposed model) found to be in good agreement with the box counting method. Findings The box counting method proves that the theoretical model is applicable. Originality/value The authors propose the first heat transfer model for the wolverine hair.

Numerical Simulation of Hot Rolled Coil Temperature Field in Hot Coil Box

2011 ◽  
Vol 338 ◽  
pp. 572-575
Author(s):  
Gui Jie Zhang ◽  
Kang Li ◽  
Ying Zi Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Coil Temperature ◽  
Hot Rolled ◽  
Strip Coil ◽  
Good Agreement

The heat transfer model was developed and the heat transfer of the strip coil stay in the hot coil box was analyzed. The temperature distribution of the strip coil was investigated use the model. The measured results are in good agreement with the calculated ones, has a guiding significance to further improve the technology.

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