Maximum and Average Flash Temperatures in Sliding Contacts

1994 ◽  
Vol 116 (1) ◽  
pp. 167-174 ◽  
Author(s):  
Xuefeng Tian ◽  
Francis E. Kennedy
Keyword(s):  
Temperature Rise ◽  
Entire Range ◽  
Function Method ◽  
Approximate Solutions ◽  
Sliding Contact ◽  
Heat Sources ◽  
Flash Temperature ◽  
Infinite Body ◽  
Average Surface ◽  
Heat Partition

The surface temperature rise for a semi-infinite body due to different moving heat sources is analyzed for the entire range of Peclet number using a Green’s function method. Analytical and approximate solutions of maximum and average surface temperatures are obtained for the cases of square uniform, circular uniform, and parabolic heat sources. Considering the heat partition between the two contacting bodies, solutions of interface flash temperature are presented for the general sliding contact case as well as for the case of sliding contact between two moving asperities.

scholarly journals Frictional Heating of Tribological Contacts

1995 ◽  
Vol 117 (1) ◽  
pp. 171-177 ◽  
Author(s):  
J. Bos ◽  
H. Moes
Keyword(s):  
Entire Range ◽  
Tribological Behavior ◽  
Mechanical Energy ◽  
Frictional Heating ◽  
Approximate Solutions ◽  
Conductivity Ratio ◽  
Flash Temperature ◽  
Heat Partitioning ◽  
Steady State Heat ◽  
Lubrication Conditions

Wherever friction occurs, mechanical energy is transformed into heat. The maximum surface temperature associated with this heating can have an important influence on the tribological behavior of the contacting components. For band contacts the partitioning of heat has already been studied extensively; however, for circular and elliptic contacts only approximate solutions exist. In this work a numerical algorithm is described to solve the steady state heat partitioning and the associated flash temperatures for arbitrary shaped contacts by matching the surface temperatures of the two contacting solids at all points inside the contact area. For uniform and semi-ellipsoidal shaped heat source distributions, representing EHL conditions and dry or boundary lubrication conditions respectively, function fits for practical use are presented giving the flash temperature as a function of the Pe´clet numbers of the contacting solids, the conductivity ratio, and the aspect ratio of the contact ellipse. These function fits are based on asymptotic solutions for small and large Pe´clet numbers and are valid for the entire range of Pe´clet numbers. By comparison with numerical results they are shown to be accurate within 5%, even for the situation of opposing surface velocities.

scholarly journals Prediction Model of the Fusion Microzone on Sliding Contact Surface

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
Yan Lu ◽  
Zuomin Liu
Keyword(s):  
Prediction Model ◽  
Temperature Rise ◽  
Function Method ◽  
Grid Method ◽  
Sliding Contact ◽  
Current Paper ◽  
Frictional Heat ◽  
Sliding Velocity ◽  
Key Points ◽  
Main Factor

The current paper is motivated by the need to understand the factors in generating the fusion microzone in sliding systems. The objectives are to analyze the different elements' varied influence on the engineering surface's temperature rise. The current paper developed the prediction model based on the thermal conduct theory. A solution based on the Green's function method is combined with the grid method for calculating the temperature rise and distribution. The research indicates that: frictional heat is closely related to the sliding velocity, its value is in proportion to the sliding velocity; the thermal properties of the material are one of the key points to decide the temperature rise; the load is another main factor in increasing the temperature rise; comparing with other elements, the roughness may be the least effective to the temperature rise.

Contact Surface Temperature Models for Finite Bodies in Dry and Boundary Lubricated Sliding

1993 ◽  
Vol 115 (3) ◽  
pp. 411-418 ◽  
Author(s):  
Xuefeng Tian ◽  
Francis E. Kennedy
Keyword(s):  
Surface Temperature ◽  
Contact Surface ◽  
Temperature Rise ◽  
Large Scale ◽  
Finite Thickness ◽  
Sliding Contact ◽  
Small Scale ◽  
Heat Sources ◽  
Real Area Of Contact ◽  
Lubricated Sliding

A model is proposed for use in determining the contact surface temperature in dry and boundary lubricated sliding systems. The model uses the concepts of small scale and large scale heat flow restrictions to divide the temperature increase in a sliding contact into two contributions, a nominal surface temperature rise and a local temperature rise. The model is particularly useful in studying the sliding surface temperature in bodies of finite thickness and in cases when the sliding contact area repeatedly sweeps over the same path on one of the contacting solids. Multiple heat sources within the real area of contact can be included, as can the effects of a cooling and/or lubricating fluid. Experiments were carried out to measure the contact surface temperature rise in several dry and boundary lubricated sliding systems. The experimental results were found to agree with the model.

Temperature Development in a Heated Contact With Application to Sliding Contacts

1952 ◽  
Vol 19 (3) ◽  
pp. 369-374
Author(s):  
Ragnar Holm
Keyword(s):  
Sliding Contact ◽  
Numerical Error ◽  
Numerical Calculations ◽  
Heat Sources ◽  
Infinite Body ◽  
Sliding Contacts ◽  
Temperature Development ◽  
The Face ◽  
Contact Surfaces

Abstract The calculation of the development of the temperature in and around a heated contact is reduced to the use of some simple formulas for certain fundamental variables and to making readings from a diagram. Applications are made to a contact that is heated by the current and to circular or oval heat sources (for example, friction-heated sliding contact-surfaces) stationary or moving on the face of a semi-infinite body. The practicability of the method is due primarily to the fact that the numerical calculations, which are made before using the standard curves, are so simple that the chance of a numerical error is very small.

The Boundary Layer Inside a Conical Surface Due to a Swirling Flow With Throughflow

1976 ◽  
Vol 43 (4) ◽  
pp. 564-566 ◽  
Author(s):  
J. M. Fabian ◽  
G. C. Oates
Keyword(s):  
Boundary Layer ◽  
Entire Range ◽  
Close Agreement ◽  
Swirling Flow ◽  
Approximate Solutions ◽  
Conical Surface

The problem of describing the boundary layer existing inside a conical surface due to the presence of a swirling flow passing through the cone is considered. Approximate solutions based upon the Karman-Polhausen method are obtained for both the laminar and the turbulent cases. The results obtained are in close agreement with known solutions previously obtained in the limits of swirl with no throughflow and throughflow with no swirl. The present results appear to be valid over the entire range of swirl to throughflow ratios.

Transient Temperature Involving Oscillatory Heat Source With Application in Fretting Contact

2007 ◽  
Vol 129 (3) ◽  
pp. 517-527 ◽  
Author(s):  
Jun Wen ◽  
M. M. Khonsari
Keyword(s):  
Heat Source ◽  
Oscillation Amplitude ◽  
The Body ◽  
Transient Temperature ◽  
Dimensionless Frequency ◽  
Heat Sources ◽  
Infinite Body ◽  
Fitting Method ◽  
Wide Range ◽  
Analytical Expressions

An analytical approach for treating problems involving oscillatory heat source is presented. The transient temperature profile involving circular, rectangular, and parabolic heat sources undergoing oscillatory motion on a semi-infinite body is determined by integrating the instantaneous solution for a point heat source throughout the area where the heat source acts with an assumption that the body takes all the heat. An efficient algorithm for solving the governing equations is developed. The results of a series simulations are presented, covering a wide range of operating parameters including a new dimensionless frequency ω¯=ωl2∕4α and the dimensionless oscillation amplitude A¯=A∕l, whose product can be interpreted as the Peclet number involving oscillatory heat source, Pe=ω¯A¯. Application of the present method to fretting contact is presented. The predicted temperature is in good agreement with published literature. Furthermore, analytical expressions for predicting the maximum surface temperature for different heat sources are provided by a surface-fitting method based on an extensive number of simulations.

Thermal Effects Due to Surface Films in Sliding Contact

1994 ◽  
Vol 116 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Brian Vick ◽  
L. P. Golan ◽  
M. J. Furey
Keyword(s):  
Thermal Properties ◽  
Temperature Rise ◽  
Thermal Effects ◽  
Three Dimensional ◽  
Sliding Contact ◽  
Frictional Heat ◽  
Solution Technique ◽  
Surface Films ◽  
Thermal Coupling ◽  
Efficient Manner

The present work examines theoretically the influence of surface coatings on the temperatures produced by friction due to sliding contact. A generalized thermal model is developed which incorporates three-dimensional, transient heat transfer between layered media with thermal coupling at multiple, interacting contact patches. A solution technique based on a variation of the boundary element method is developed and utilized. The method allows for the solution of the distribution of frictional heat and the resulting temperature rise in an accurate yet numerically efficient manner. Results are presented showing the influence of film thickness, thermal properties, velocity, and contact area on the division of heat and surface temperature rise. The results show that a film with thermal properties different than those of the substrate can have a pronounced effect on the predicted temperature rise.

Modeling of Cutting Temperature in Near Dry Machining

2005 ◽  
Vol 128 (2) ◽  
pp. 416-424 ◽  
Author(s):  
Kuan-Ming Li ◽  
Steven Y. Liang
Keyword(s):  
Heat Source ◽  
Heat Loss ◽  
Temperature Rise ◽  
Flank Wear ◽  
Cutting Temperature ◽  
Heat Sources ◽  
Dry Machining ◽  
Machining Processes ◽  
Tool Flank Wear ◽  
Dry Cooling

Near dry machining refers to the condition of applying cutting fluid at relatively low flow rates, on the order of 2-100ml∕h, as opposed to the conventional way of using either a large quantity, typically of about 10l∕min, as in wet machining; or no fluid at all, as in dry machining. One important expectation of applying fluids is to control the cutting temperature, which is an important parameter for tool life and part dimensional accuracy in machining processes. In this context, the understanding of cutting temperature variation corresponding to the near dry cooling and lubrication is of interest. This paper models the temperature distributions in the cutting zone under through-the-tool near dry cooling condition. The heat source method is implemented to estimate the cutting temperatures on the tool-chip interface and the tool-workpiece interface. For the temperature rise in the chip, the effects of the primary heat source and the secondary heat source were modeled as moving heat sources. For the temperature rise in the tool, the effects of the secondary heat source, the heat loss due to cooling, and the rubbing heat source due to the tool flank wear, were modeled as stationary heat sources. For the temperature rise in the workpiece, the primary heat source, the heat loss due to cooling, and the rubbing heat source due to the tool flank wear were modeled as moving heat sources. The model describes the dual effects of air-oil mixture in near dry machining in terms of the reduction of cutting temperature through the cooling effect, as well as the reduction of heat generation through the lubricating effect. To pursue model calibration and validation, embedded thermocouple temperature measurement in cutting medium carbon steels with uncoated carbide insets were carried out. The model predictions and experimental measurements show reasonable agreement and results suggest that the combination of the cooling and the lubricating effects in near dry machining reduces the cutting temperatures on the tool-chip interface by about 8% with respect to dry machining. Moreover, the cutting speed remains a dominant factor in cutting temperature compared with the feed and the depth of cut in near dry machining processes.

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