応用機械工学ジャーナル

概要

Inspection of Hydrodynamic Lubrication in Infinitely Long Journal Bearing with Oscillating Journal Velocity

Verma A

Unsteady transient analysis is carried out for hydro-dynamically lubricated journal bearing with infinitely long approximation. The performance characteristics are investigated by oscillating the journal velocity as a ‘sine’ function of the angle for which the journal rotates with an angular speed. Results comprising of Minimum lubricant film thickness, Dynamic pressure and load, Wall shear stress, Eccentricity, Temperature distribution and heat flux with respect to time are presented in the analysis graphically with the aid of ORIGION PRO 8. The journal bearing is analyzed in ANSYS 14.0 ‘Transient Thermal’ package. The journal is modeled as a “moving wall” with an absolute rotational speed of 3000 rpm. Appropriate equations and numerical solutions (Simpson’s 1/3rd integration rule and Newton-Raphson method) are developed using ‘C programming’ for solving the Reynolds compressible differential equation. The numerical procedure is fully automated and the scheme converges rapidly. Design parameters are included in the computation taking into account turbulence and gravity. After carrying out all the above discussed scrutiny, it was observed that minimum oil film thickness is a function of oscillating velocity, pressure is inversely proportional to the minimum oil film thickness, and eccentricity and wall shear stress are also a function of the oscillating journal velocity. While the value of coefficient of friction and coefficient of friction variable are found to be maximum at the maximum velocity, thus leading to its dependency on the oscillating journal velocity. Also, variation of temperature distribution and heat flux with respect to time leads to converging of the results. Validating McKee’s investigation leads to completion of the venture