On the effects of the temperature profile approximation in thermal Newtonian solutions of elastohydrodynamic lubrication line contacts

Kazama, Toshiharu; Ehret, Pascal; Taylor, C. M.

doi:10.1243/1350650011541666

Cited by 23 publications

(14 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This assumption of a polynomial temperature distribution has been made by a number of other researchers. For instance, Kazama et al [38] conducted a two-dimensional energy equation to simulate the through-thickness temperature variation and predicted a quadratic profile. Moreover, in research by Sadeghi and co-workers [39,40], the temperature profile as a function of viscosity, conductivity and sliding speed was obtained numerically under elastohydrodynamic conditions and was close to parabolic in shape.…”

Section: Methods To Obtain the Temperature Profile Through The Thicknementioning

confidence: 99%

3D Measurements of Lubricant and Surface Temperatures Within an Elastohydrodynamic Contact

Reddyhoff

Dini

2017

Tribol Lett

View full text Add to dashboard Cite

We present an infrared microscopy technique, capable of measuring the temperature of both the bounding surfaces and the oil film in an elastohydrodynamic contact. This technique can, for the first time, spatially resolve the oil film temperature in three dimensions. The contact is produced by loading a steel ball against a sapphire disc, and the film is viewed using an infrared microscope focussing through the disc. Two band pass filters are used to isolate the radiation from the oil film, and Planck's law is applied to data obtained at a known temperature as part of the calibration procedure. The proposed technique requires the emissivity of the oil film to be measured, which is acquired in situ and is shown to vary strongly as a function of thickness and temperature. The technique is validated under pure rolling conditions, when the temperature of the oil film is equal to the controlled lubricant reservoir temperature, and also compared to an equation commonly used to predict average film temperatures, confirming the value of the unknown constant. The technique is then used to gain insights into the thermal/rheological behaviour within a contact. This is important since the temperature of elastohydrodynamic contacts is critical in determining friction and hence the efficiency of machine components and this technique enables much needed validation and provides input data for CFD and numerical simulations.

show abstract

Section: Methods To Obtain the Temperature Profile Through The Thicknementioning

confidence: 99%

3D Measurements of Lubricant and Surface Temperatures Within an Elastohydrodynamic Contact

Reddyhoff

Dini

2017

Tribol Lett

View full text Add to dashboard Cite

show abstract

“…When the density  0 remains constant, and the mean viscosity  m across the film is introduced, the parameters G 0 , G 1 , G 2 , and G 3 are given as follows (Ferron et al, 1983;Kazama et al, 2001):…”

Section: Basic Equationsmentioning

confidence: 99%

Improving the static characteristics of hydrodynamic bearings using the viscosity-temperature relations of lubricants

Kazama

2016

Mechanical Engineering Letters

View full text Add to dashboard Cite

The possibility of improving the static characteristics of hydrodynamic bearings using the inverse viscosity-temperature relations of liquid lubricants is theoretically examined. A simplified model that comprises the Reynolds equation with a change in the mean oil viscosity across the film as a function of temperature and that is based on the thermal lubrication theory is applied. The solutions are numerically obtained for linear sliding bearings, tapered land bearings, and cosine pad bearings, wherein the temperature distributions are given as known values and the viscosity distributions are determined beforehand. The bearing geometry and temperature profiles are selected as parameters. When the temperature in the converged region close to the minimum clearance is low, the fluid pressure becomes larger; thus, the friction coefficient becomes smaller, whereas the leakage flow rate changes slightly. This behavior may contribute to improving the static characteristics of hydrodynamic bearings.

show abstract

“…First moment of energy equation yields Coefficients appearing in equations (19) and (20) are given in Appendix 2.…”

Section: Energy Equationmentioning

confidence: 99%

“…The Legendre coefficients of temperatures T 0 , T 1 , T 2 , and T 3 are obtained by solving equations (19), (20) along with equations (15(a) and (b)). Thermal pressure is computed iteratively using equation (10) after incorporating thermal effects in viscosity.…”

Section: Computational Proceduresmentioning

confidence: 99%

Effects of starvation and viscous shear heating in hydrodynamically lubricated rolling/sliding line contacts

Anandan

Pandey

Jagga

et al. 2006

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

Combined effects of viscous shear heating and starvation in hydrodynamically lubricated high-speed rolling/sliding line contacts have been investigated numerically by using an efficient computational method for the solution of energy equation in which temperature distribution across the film is approximated by Legendre polynomial. Effects of starvation on minimum film thickness, traction coefficient, and mid-film temperature rise are computed for lightly loaded, lubricated rolling/sliding line contacts. Lubricant starvation in the contact has been created by gradually reducing the length of the computational domain from the inlet side. The performance parameters in the line contact have been evaluated for high-rolling speeds (15 -45 m/s), light loads (10 Â 10 3 -17 Â 10 3 N/m), and slip values varying up to 10 per cent. Significant reduction in minimum film thickness, traction coefficient, and maximum mid-film temperature rise has been observed with the increase in the severity of starvation. The analysis reveals that the existence of starvation seems to be beneficial in terms of reduced traction and temperature rise provided there is a continuous film at the contact. On the basis of this work, empirical relations are developed for the prediction of non-dimensional minimum film thickness, traction coefficient, and non-dimensional maximum mid-film temperature rise in the contact in terms of various operational parameters viz. thermal loading parameter (Q), non-dimensional load (W ), slip (S ), and starvation parameter (jX s j).

show abstract

On the effects of the temperature profile approximation in thermal Newtonian solutions of elastohydrodynamic lubrication line contacts

Cited by 23 publications

References 24 publications

3D Measurements of Lubricant and Surface Temperatures Within an Elastohydrodynamic Contact

3D Measurements of Lubricant and Surface Temperatures Within an Elastohydrodynamic Contact

Improving the static characteristics of hydrodynamic bearings using the viscosity-temperature relations of lubricants

Effects of starvation and viscous shear heating in hydrodynamically lubricated rolling/sliding line contacts

Contact Info

Product

Resources

About