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Theoretical analysis of jornal bearings lubricated with non-Newtonian fluid based Carreau viscosity model

Mongkolwongrojn M., Aiumpornsin Ch.

International Journal of Applied Mechanics and Engineering

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2005

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Vol. 10, no. spec.

245-253

EN

The static and dynamic characteristics of journal bearings lubricated with non-Newtonian fluids based on Carreau viscosity model have been investigated theoretically. The time-dependent modified Reynolds equation and the adiabatic energy equations have been formulated using Carreau viscosity model. The simultaneous system of modified Reynolds and adiabatic energy equations were solved numerically with boundary conditions using finite difference technique. The linearized bearing reactions and the journal motion can be approximated to obtain the spring and damping coefficient. Static characteristics are presented as pressure profile, temperature profile, load carrying capacity and the coefficient of friction with varying the eccentricity ratio. The stiffness coefficients, damping coefficients and the stability of the journal bearing are investigated with varying the parameters of the non-Newtonian fluid model. In this study, the shear rate of non-Newtonian lubricant and the model parameters have significant effects on the characteristics of journal bearings lubricated with the non-Newtonian fluids.

2

Effect of model parameters on elastohydrodynamic lubrication line contact with non-Newtonian Carreau viscosity model

Mongkolwongrojn M., Wongseedakeaw K., Yawong S., Jeenkour P., Aiumpornsin C.

International Journal of Applied Mechanics and Engineering

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2005

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Vol. 10, no. spec.

255-261

EN

The compressible elastohydrodynamic (EHD) lubrication of two surfaces under line contact has been investigated in steady state operating conditions. The modified Reynolds equation with non-Newtonian fluids has been formulated using Carreau viscosity model. The simultaneous systems of modified Reynolds and elasticity equations with boundary conditions were solved numerically using Newton Raphson technique. The performance characteristics of the elastohydrodynamic lubrication under two surfaces in line contact were calculated and presented for varying the non-Newtonian Carreau viscosity model parameters. The pressure profile, film thickness profile, load capacity were investigated in both static and dynamic conditions. This simulation showed the significant effect of model parameters on elastohydrodynamic lubrication under heavy load conditions.

3

Static and dynamic characteristics of journal bearings with non-newtonian palm-based oils

Mongkolwongrojn M., Aiumpornsin Ch.

International Journal of Applied Mechanics and Engineering

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2003

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Vol. 8, no. spec.

79-86

EN

This paper presents the investigation of the static and dynamic characteristics of hydrodynamic journal bearings lubricated with non-newtonian palm-based oils. The palm oil was mixed with 0.2% ZDTP and 1% ZDTP to reduce oxidation and increase lubricity. In this study, the power law model is proposed as a rheology model of palm-based oil and the relationship between the shear stress and shear rate was obtained experimentally. The time-dependent modified Reynolds equation, and adiabatic energy equation were formulated for full circular bearings. Finite difference method was used to calculate both the static and dynamic characteristics of the bearings such as pressure distribution, temperature distribution, attitude angle, stiffness and damping coefficients. The results shows that the palm-based oils have potential to use as a biodegradable lubricant.