CFD Performance Analysis of Journal Bearing Using Coconut Oil as Lubricant

Abstract

Lubrication is one of the important factors for a journal bearing to function well. Therefore, the use of bio-lubricants such as coconut oil and vegetable oil are highly recommended for their high level of biodegradability to reduce the risk of environmental pollution. Vegetable oil like coconut oil has a great lubricating quality including low friction coefficient and improved oxidation stability which is very suitable to be used as a lubricant. The performance assessment of journal bearings utilizing coconut oil as a bio-lubricant and varying angular velocity and eccentricity ratio will be the main emphasis of this study. The behavior of the journal bearing with coconut oil as the lubricant will be examined using the Computational Fluid Dynamics (CFD) program, ANSYS Fluent. Using ANSYS Fluent, the pressure distribution of pure coconut oil is analytically studied. To evaluate the efficacy of each lubricant with a varied value of angular velocity utilized by the journal in journal bearings, average viscosity, viscosity index, and produced maximum pressure can be discovered under the lubrication of the journal bearing. Using the values of angular velocity with the same value of dynamic viscosity and density as properties for the coconut oil were used to run the simulation for the journal bearing. The result obtained from the simulation for eccentricity ratio of 0.2 with an angular velocity of 5000rpm is 205926.1 meanwhile the result for eccentricity ratio of 0.8 with same angular velocity value is 9661441. Each result signifies those different value of angular velocity with different value of eccentricity ratio that effects the bearing design itself occurs different result.