Thin Film Modelling for Aero-Engine Bearing Chambers

2011 ◽  
Author(s):  
C. Wang ◽  
H. P. Morvan ◽  
S. Hibberd ◽  
K. A. Cliffe
Keyword(s):  
Thin Film ◽  
Film Flow ◽  
Momentum Equation ◽  
Thin Film Flow ◽  
Simple Formulation ◽  
Physical Mechanisms ◽  
Thin Film Model ◽  
Aero Engine ◽  
Flow Features ◽  
Engine Bearing

This paper presents a dynamic mathematical model describing the thin film flow in aero-engine bearing chamber. By analyzing the depth averaged continuity equation and momentum equation term by term, the comprehensive physical mechanisms driving thin film flow are revealed. The terms that require extra modeling work are then identified. As a useful first approach, a thin film model based on presumed quadratic velocity profile is adopted. A preliminary study shows that this model can include the main film flow features in aero-engine bearing chamber, whilst maintain simple formulation and work efficiently. Finally, a converging computational strategy is obtained towards the numerical simulation of engine bearing chamber.

Specifying and Benchmarking a Thin Film Model for Oil Systems Applications in ANSYS Fluent

2012 ◽  
Author(s):  
C. Wang ◽  
H. P. Morvan ◽  
S. Hibberd ◽  
K. A. Cliffe ◽  
A. Anderson ◽  
...  
Keyword(s):  
Thin Film ◽  
Film Flow ◽  
Test Case ◽  
Thin Film Flow ◽  
Ansys Fluent ◽  
Film Model ◽  
Thin Film Model ◽  
Software Product ◽  
Aero Engine ◽  
Engine Bearing

A thin film model developed for calculating the oil film flow in aero-engine bearing chamber is described. The performance of the model, which has been implemented in the commercial computational fluid dynamics software product: ANSYS Fluent, is benchmarked by comparing the computational results obtained from a Nottingham UTC in-house code and a development version of Fluent. Both codes are used to solve thin film flow in a test case configuration and based on the same finite area method. With identified constraints, the two implementations agree well.

scholarly journals Assessment of an Enhanced Thin Film Model to Capture Wetting and Drying Behavior in an Aero-Engine Bearing Chamber

2019 ◽  
Author(s):  
Kuldeep Singh ◽  
Medhat Sharabi ◽  
Stephen Ambrose ◽  
Carol Eastwick ◽  
Richard Jefferson-Loveday ◽  
...  
Keyword(s):  
Thin Film ◽  
Contact Angle ◽  
Film Thickness ◽  
Wetting And Drying ◽  
Film Model ◽  
Thin Film Model ◽  
Aero Engine ◽  
Thickness Prediction ◽  
Drying Behavior ◽  
Engine Bearing

Abstract In the present work, a wetting and drying model is coupled with Eulerian Thin-Film model (ETFM) to analyze the wetting and drying behavior inside the bearing chamber. In the enhanced model, an additional source term is included to account for the contact angle effect. These models were coupled with volume-of-fluid (VOF) such that the core region is resolved by VOF and region close to the chamber walls, where a thin film is expected is resolved by either ETFM or enhanced ETFM model. Numerical studies are conducted for a shaft speed of 5,000 rpm, lubricant and air flow rates of 100 1/hr and 10 g/s respectively, at a scavenging ratio of 4. In the case of enhanced ETFM model lubricant to surface contact angle was varied from 10° to 45°. The performance of enhanced ETFM model is evaluated to capture drying and wetting behavior on a flat plate and found to be satisfactory. Film thickness prediction of enhanced ETFM model is found to be comparable with the VOF predictions reported in the literature. The effect of contact angle on the spreading of oil and film thickness is found to be small for the investigated conditions on an aero-engine bearing chamber.

scholarly journals Prediction of Film Thickness of an Aero-Engine Bearing Chamber Using Coupled VOF and Thin Film Model

2019 ◽  
Author(s):  
Kuldeep Singh ◽  
Medhat Sharabi ◽  
Stephen Ambrose ◽  
Carol Eastwick ◽  
Richard Jefferson-Loveday
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Air Flow ◽  
Shaft Speed ◽  
Oil Film ◽  
Film Model ◽  
Thin Film Model ◽  
Wide Range ◽  
Aero Engine ◽  
Engine Bearing

Abstract In the present work, a coupled volume-of-fluid (VOF) model with Eulerian thin-film model (ETFM) approach is used to predict the film thickness in an aero-engine bearing chamber. Numerical studies are conducted for a wide range of shaft speeds with lubricant and air flow rates of 100 1/hr and 10 g/s respectively, at a scavenge ratio of 4 on a simplified bearing chamber test rig. Air-flow analysis inside the bearing chamber is also assessed. Primary and secondary airflow predictions are found to be in good agreement with the experimental results. The coupled ETFM+VOF approach is found to be sensitive enough to capture the qualitative trend of oil film formation and distribution over the chamber wall. Oil collection near the sump at a low shaft speed and a rotating oil film at a higher shaft speed are well captured.

Influence of circumferential waviness on engine bearing performance

2000 ◽  
Vol 214 (1) ◽  
pp. 51-61 ◽  
Author(s):  
D. S. Mehenny ◽  
C. M. Taylor
Keyword(s):  
Thin Film ◽  
Film Flow ◽  
Film History ◽  
Two Dimensional ◽  
Thin Film Flow ◽  
Main Bearing ◽  
Automotive Engine ◽  
Form Errors ◽  
Minimum Film Thickness ◽  
Engine Bearing

The influence of circumferential waviness of the journal on the lubrication of the inter-main bearing of an automotive engine is investigated using a theoretical analysis. The analysis is for two-dimensional thin film flow, with oil-film history. The bearing and shaft surfaces were assumed to be rigid and the lubricant isoviscous. The results show a significant influence of shaft lobing on predicted maximum film pressure and minimum film thickness, particularly as the number and size of lobes increase. It is concluded that, for satisfactory operation of engine bearings, circumferential form errors of the shaft need to be controlled.

scholarly journals Optimal Homotopy Asymptotic Method for a thin film flow of a pseudo plastic fluid draining down or lifting up on a cylindrical surface

2013 ◽  
Vol 19 (4) ◽  
pp. 513-527
Author(s):  
Kamran Alam ◽  
M.T. Rahim ◽  
S. Islam ◽  
A.M. Sidiqqui
Keyword(s):  
Thin Film ◽  
Asymptotic Method ◽  
Cylindrical Surface ◽  
Film Flow ◽  
Vertical Cylinder ◽  
Stokes Number ◽  
Velocity Shear ◽  
Thin Film Flow ◽  
Fluid Velocities ◽  
Optimal Homotopy Asymptotic Method

In this study, the pseudo plastic model is used to obtain the solution for the steady thin film flow on the outer surface of long vertical cylinder for lifting and drainage problems. The non-linear governing equations subject to appropriate boundary conditions are solved analytically for velocity profiles by a modified homotopy perturbation method called the Optimal Homotopy Asymptotic method. Expressions for the velocity profile, volume flux, average velocity, shear stress on the cylinder, normal stress differences, force to hold the vertical cylindrical surface in position, have been derived for both the problems. For the non-Newtonian parameter ?=0, we retrieve Newtonian cases for both the problems. We also plotted and discussed the affect of the Stokes number St, the non-Newtonian parameter ? and the thickness ? of the fluid film on the fluid velocities.

scholarly journals MHD thin film flow of the Oldroyd-B fluid together with bioconvection and activation energy

2021 ◽  
pp. 101218
Author(s):  
Farhan Ahmad ◽  
Taza Gul ◽  
Imran Khan ◽  
Anwar Saeed ◽  
Mahmoud Mohamed Selim ◽  
...  
Keyword(s):  
Thin Film ◽  
Activation Energy ◽  
Film Flow ◽  
Thin Film Flow
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