Thermo EHL Case Study

ρ(p)=ρ_0 ( 1+(1.16 p)/(1+1.7p))(1.0-ε(T-T_0 )
Peiran Yang et al. (1993) [15] presented a straight forward, fast and robust algorithm for Thermo EHL line contact problems. As compared to conventional N-R method this method was more efficient for pressure calculation and can be used for both micro and Non-Newtonian Thermo EHL. This can also be used for solving transient TEHL with good stability numerically. For calculating the pressure distribution they used the dimensionless form of the equations. FDM was used by them to calculate the temperature distribution numerically. The result obtained is presented in Fig 2. (a) (b)
Fig 2: (a) Pressure distribution and film thickness profile of Non-Newtonian fluid and (b) temperature rise
P. Monmousseau et al. (2000) [16] studied the transient TEHL behaviour of a tilting-pad journal bearing exposed to severe operating conditions. A rapid seizure or a safe running are the two different possible outcome. The initial radial bearing clearance, the feeding temperature, the nominal rotational speed and the elapsed time of acceleration are strongly coupled with the seizure phenomenon during the start-up period. The constitutive equations are solved using finite difference method. For the generalized Reynolds equation the Gauss–Seidel iterative scheme with over-relaxation was employed. For solving the energy and heat transfer equations an explicit method was applied. The pad positions were determined by applying implicit Euler method to the momentum equations for each
(1995) [17] adopted a fast multigrid approach for the analysis of TEHL under rolling/sliding circular contacts at high slip ratios and high loads. This fast solver is combination of direct iteration, multigrid, Newton-Raphson, Gauss-Seidel iteration and multilevel multi-integration methods. It reduces the computational complexity for the thermal EHL problem under rolling/sliding circular contacts. Different methods with their use is presented in Table 2. Increasing slip ratio, dimensionless speed and load results into rise in the maximum mid film and surfaces temperature in the Hertzian contact region. Increase in load and slip ratio, and decrease in dimensionless speed decreases the minimum film thickness. The temperature distribution obtained is shown in Fig 3. Xiaoling Liu et al. (2002) [18] presented a solution to finite line contact problem between an infinite plane and an axially profiled cylindrical roller. In a finite line contact, the minimum film thickness, the highest film temperature and the maximum pressure occurs at the end regions of the roller. The numerical solution was obtained by a pressure–temperature iteration between the Reynolds equation and the energy equations along with boundary conditions. A multilevel method was used to solve the pressure field. Multi-level multi integration method was used to solve the elastic