scholarly journals Calculation of lubricant flow in the slide bearing of the aviation engine reducer

2019 ◽  
Vol 18 (2) ◽  
pp. 75-88 ◽  
Author(s):  
M. V. Siluyanova ◽  
A. О. Fertikov
Keyword(s):  
Pressure Distribution ◽  
Structure Calculation ◽  
Heavy Duty ◽  
Supporting Structure ◽  
Oil Supply ◽  
Slide Bearing ◽  
Turbojet Engine ◽  
Distribution Calculation ◽  
Lubricant Flow ◽  
Shaft Journal

A method has been developed for calculating the pressure distribution in a cylindrical slide bearing. We present the process of designing a heavy-duty slide bearing as a component of the reduction gearbox of a bypass turbojet engine as the object of our investigation. The process comprises the following stages: specification of the supporting structure; calculation of pressure distribution in the slide bearing for different eccentricities and angles of rotation of the shaft journal; calculation of the effect of shaft journal precession on pressure distribution; calculation of pressure distribution taking into account the channels of oil supply to the bearing. The results obtained in the experimental activities are given. The analysis carried out shows that the calculation helps to predict the location and size of pressure and rarefaction areas, to position the holes for oil supply, which will significantly improve the conditions of lubricant flow in the bearing.

Influences of Recess Geometry and Restrictor Dimension on Flow Patterns and Pressure Distribution of Hydrostatic Bearings

2007 ◽  
Author(s):  
Cheng-Hsien Chen ◽  
Yuan Kang ◽  
Yeon-Pun Chang ◽  
De-Xing Peng ◽  
Ding-Wen Yang
Keyword(s):  
Pressure Distribution ◽  
Stokes Equations ◽  
Flow Patterns ◽  
Lubricant Film ◽  
Navier Stokes ◽  
Width Ratio ◽  
Navier Stokes Equations ◽  
Hydrostatic Bearing ◽  
Lubricant Flow ◽  
Land Width

This paper studies the influences of recess geometry and restrictor dimensions on the flow patterns and pressure distribution of lubricant film, which are coupled effects of hybrid characteristics of a hydrostatic bearing. The lubricant flow is described by using the Navier-Stokes equations. The Galerkin weighted residual finite element method is applied to determine the lubricant velocities and pressure in the bearing clearance. The numerical simulations will evaluate the effects of the land-width ratio and restriction parameter as well as the influence of modified Reynolds number and the jet-strength coefficient on the flow patterns in the recess and pressure distribution in lubricant film. On the basis of the simulation drawn from this study, the simulated results are expected to help engineers make better use of the design of hydrostatic bearing and its restrictors.

Experimental Investigation of Lubricant Flow Properties Under Micro Oil Supply Condition

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Shanhua Qian ◽  
Dan Guo ◽  
Shuhai Liu ◽  
Xinchun Lu
Keyword(s):  
Film Thickness ◽  
Contact Region ◽  
Elastohydrodynamic Lubrication ◽  
Relative Length ◽  
Flow Properties ◽  
Oil Supply ◽  
Supply Condition ◽  
Lubricant Flow ◽  
Oil Pool ◽  
Disc Configuration

Lubricant flow properties of polyalphaolefin (PAO) oil have been experimentally investigated based on a ball-on-disc configuration under micro oil supply condition. The oil pool shape and central film thickness in the contact region were obtained using fluorescence microscopy and optical interferometry, respectively. It has been found that the relative length between the inlet meniscus and Hertzian center point in the oil pool to Hertzian radius was much larger than 1 in a smaller lubricant supply of 20 μl, and the corresponding contact region initially entered the elastohydrodynamic lubrication (EHL) region and then became starved with the increasing speed. The variations of the relative film thickness as a function of starvation degree and the ratio of relative length to Hertzian radius were proposed to explain the obtained results. Besides, the fluorescence technique was used to directly observe the inlet meniscus position of the oil pool and helped to gain more understanding of the lubricant flow properties under micro oil supply condition.

Dynamic behaviours of piston rings and their practical impact. Part 2: Oil transport, friction and wear of ring/liner interface and the effects of piston and ring dynamics

2002 ◽  
Vol 216 (4) ◽  
pp. 229-248 ◽  
Author(s):  
T Tian
Keyword(s):  
Friction And Wear ◽  
Surface Profile ◽  
Theoretical Models ◽  
Heavy Duty ◽  
Oil Consumption ◽  
Oil Supply ◽  
Oil Transport ◽  
Ring Dynamics ◽  
Calculation Results ◽  
Practical Impact

The paper discusses several important processes that have great impact on the lubrication between the top two rings and the liner. The analysis is conducted on the basis of the calculation results on a heavy-duty (HD) diesel engine using theoretical models. Oil supply mechanisms to different liner regions are analysed, and emphasis is given to the oil transport to the top liner region that is found critical to friction, wear and oil consumption in HD diesel engines. Additionally, the paper discusses the oil supply to the second ring, its uncertainties and the effect on the prediction of the performance of the top two rings. Furthermore, the effects of dynamics of the piston and rings on friction, wear and oil transport are illustrated and the effects of bore distortion on oil transport are discussed. For practical purposes, a formula to describe the second ring running surface profile is given based on simple geometrical constraint. A new truncation method is rendered for plateau surface roughness in order to effectively use the existing mixed lubrication models.

scholarly journals On the Possibilities of Decreasing Power Loss in Large Tilting Pad Thrust Bearings

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Michal Wasilczuk ◽  
Grzegorz Rotta
Keyword(s):  
Power Loss ◽  
Power Plants ◽  
Thrust Bearing ◽  
Fluid Film ◽  
Total Power ◽  
Thrust Bearings ◽  
Oil Supply ◽  
Water Power ◽  
Lubricant Flow ◽  
Tilting Pad

Different systems of direct oil supply have been developed in order to facilitate efficient introduction of fresh lubricant to the oil gap and reduction of churning power loss in tilting pad thrust bearings. Up to now there is no documented application of the supply groove in large thrust bearings used in water power plants. The results of modeling lubricant flow in the lubricating groove of a thrust bearing pad will be presented in the paper. CFD software was used to carry out fluid film calculations. Such analysis makes it possible to modify groove geometry and other parameters and to study their influence on bearing performance. According to the results a remarkable decrease in total power loss due to avoiding churning losses can be observed in the bearing.

Investigation of the Flow Field and the Pressure Recovery in a Gas Turbine Exhaust Diffuser at Design, Part-Load and Over-Load Condition

2020 ◽  
Author(s):  
Maximilian Bauer ◽  
Simon Hummel ◽  
Markus Schatz ◽  
Martin Kegalj ◽  
Damian M. Vogt
Keyword(s):  
Mach Number ◽  
Flow Field ◽  
Pressure Distribution ◽  
Gas Turbine ◽  
Total Pressure ◽  
Operating Conditions ◽  
Pressure Recovery ◽  
Heavy Duty ◽  
Part Load ◽  
Design Load

Abstract The performance of axial diffusers installed downstream of heavy duty gas turbines is mainly affected by the turbine load. Thereby the outflow varies in Mach number, total pressure distribution, swirl and its tip leakage flow in particular. To investigate the performance of a diffuser at different load conditions, a generic diffuser geometry has been designed at ITSM which is representative for current heavy duty gas turbine diffusers. Results are presented for three different operating conditions, each with and without tip flow respectively. Part-load, design-load and over-load operating conditions are defined and varied at the diffuser inlet in terms of Mach number, total pressure distribution and swirl. Each operating point is investigated experimentally and numerically and assessed based on its flow field as well as the pressure recovery. The diffuser performance shows a strong dependency on the inlet swirl and total pressure profile. A superimposed tip flow only influences the flow field significantly when the casing flow is weakened due to casing separation. In those cases pressure recovery increases with additional tip flow. There is a reliable prediction of the CFD simulations at design-load. At part-load, CFD overpredicts the strut separation, resulting in an underpredicted overall pressure recovery. At over-load, CFD underpredicts the separation extension in the annular diffuser but overpredicts the hub wake. This leads to a better flow control in CFD with the result of an overpredicted overall pressure recovery.

Numerical Method for Pressure Distribution Calculation on Spherical Distribution Pair of IHT

2011 ◽  
Vol 52-54 ◽  
pp. 1427-1432
Author(s):  
Shi Hua Yuan ◽  
Ding Hua Liu ◽  
Chao Wei
Keyword(s):  
Pressure Distribution ◽  
Reynolds Equation ◽  
Thickness Distribution ◽  
Transformation Method ◽  
Physical Domain ◽  
Spherical Distribution ◽  
Distribution Calculation ◽  
Curvilinear Grid ◽  
Control Equation ◽  
Flux Conservation

To calculate the pressure distribution of oil film on spherical port plate of Innas hydraulic transformer (IHT), finite difference method (FDM) based on boundary fitted coordinate (BFC) technique is presented. Spherical curvilinear grid system was obtained with a coincident boundary of irregular physical area. The flux conservation form of Reynolds’ equation was applied as control equation. By FDM, the thickness distribution and pressure distribution of distribution pair were calculated. It shows that BFC transformation method is advantaged to closely simulate the physical domain with complex geometrical boundaries.

Impact of the Inflow Conditions on the Heavy-Duty Gas Turbine Exhaust Diffuser Performance

2011 ◽  
Vol 134 (4) ◽  
Author(s):  
Vladimir Vassiliev ◽  
Stefan Irmisch ◽  
Samer Abdel-Wahab ◽  
Andrey Granovskiy
Keyword(s):  
Pressure Distribution ◽  
Gas Turbines ◽  
Field Measurements ◽  
Heavy Duty ◽  
Flow Angle ◽  
Heavy Duty Gas Turbine ◽  
Gas Turbine Exhaust ◽  
The Impact ◽  
Inflow Conditions ◽  
Turbine Exhaust

The flow in exhaust diffusers along with the channel geometry strongly depends on the inflow conditions, including Mach number level, total pressure distribution, flow angle, and turbulence. In the first part of this paper, the impact of these parameters is analyzed using computational fluid dynamics, experimental data from the test rig, and field measurements. A widespread opinion is that the optimal condition for the diffuser is an axial uniform inflow. However, it is shown in this paper that nonuniform pressure distribution compared with a uniform one can lead to better diffuser performance and that a moderate residual swirl can improve the performance as well. In the second part of this paper, the minimization of exhaust losses in heavy-duty gas turbines is discussed and illustrated by two practical examples.

Static characteristics analysis of spherical hybrid sliding bearings

2019 ◽  
Vol 72 (1) ◽  
pp. 93-100
Author(s):  
Jian Wang ◽  
Jing Feng Shen ◽  
Ya Wen Fan
Keyword(s):  
Pressure Distribution ◽  
Static Characteristics ◽  
Eccentricity Ratio ◽  
Sliding Bearings ◽  
Content Type ◽  
Oil Film ◽  
Rotating Speed ◽  
Oil Supply ◽  
Supply Pressure ◽  
Bearing Clearance

Purpose The spherical hybrid sliding bearings (SHSBs) can be used in ultra-precision and heavy-duty machine tools. However, there is little related research for these bearings. The purpose of this study is to investigate the static characteristics and effect factors affecting SHSBs by fluid lubrication. Design/methodology/approach Based on the theories of fluid lubrication, the Reynolds equation of general Newtonian fluid is derived to obtain the steady-state lubrication equation. The system is solved by the finite difference method and the relaxation iterative method on the staggered grid to obtain the thickness and the pressure distribution of the oil film. The radial and axial load capacities of SHSBs are determined by the pressure field integration over the spherical surface. Findings The results show that the parameters such as oil supply pressure, bearing clearance, eccentricity ratio, rotating speed and orifices’ number affecting the static characteristics of bearings are significant and the cross-coupling effect exists. Originality/value The lubrication model of SHSB is established to analyze the pressure distribution with a variety of oil film thickness. The laws of oil supply pressure, bearing clearance, eccentricity ratio, rotating speed and orifices’ number on the load capacities are researched.

Sign in / Sign up

Export Citation Format

Share Document