Efficiency Analysis of Rapid Turbocharger With Alternative Bearing Design

2005 ◽  
Vol 128 (1) ◽  
pp. 137-141 ◽  
Author(s):  
Abdelkrim Liazid ◽  
Lahouari Izidi ◽  
Mohamed Bencherif
Keyword(s):  
Diesel Engine ◽  
Reynolds Equation ◽  
Efficiency Analysis ◽  
Journal Bearings ◽  
Air Bearing ◽  
Global Evolution ◽  
Bearing Load ◽  
Innovative Idea ◽  
Bearing Design

This work presents the possibility to adapt self-acting air bearing to a rapid diesel engine turbocharger originally designed with oil journal bearings. The aim of this innovative idea is to estimate a global evolution of efficiency which is a parameter that strongly influences the inlet air mass of the diesel engine. This study deals with radial bearings and illustrates the advantages and the limits of the aerodynamic bearing application. First, the computing concerns the determination of the bearing load by resolving the Reynolds equation. So, the determination of the neat turbine power by a mathematical model using some experimental data is also made. Lastly, a comparison with the original hydrodynamic bearings is presented. Some discussions are also developed.

Theoretical Analysis of Externally Pressurized Air Journal Bearing

1970 ◽  
Vol 12 (2) ◽  
pp. 123-129 ◽  
Author(s):  
B. C. Majumdar
Keyword(s):  
Experimental Data ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Design Parameters ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Dimensional Parameters ◽  
Bearing Design

A theoretical investigation is made to predict the performance of an externally pressurized air journal bearing having several pressure sources. The pressure distribution, which leads to the determination of load-carrying capacity and flow requirement, is obtained by solving Reynolds equation numerically. The load and flow, expressed in non-dimensional parameters, are presented for different bearing design parameters (dimensionless). The results predicted by this method are compared with others' experimental data.

Tribological design of hydrodynamic sliding journal bearings – formulating new functional charts

2005 ◽  
Vol 57 (1) ◽  
pp. 4-11 ◽  
Author(s):  
C. Pandazaras ◽  
G. Petropoulos
Keyword(s):  
Design Methodology ◽  
Reynolds Equation ◽  
Journal Bearings ◽  
Content Type ◽  
Topographic Features ◽  
Operational Characteristics ◽  
Innovative Methodology ◽  
Limited Length ◽  
New Type

PurposeThis paper aims to introduce an innovative methodology for the determination of operational characteristics of journal bearings (j‐bs) through using new type charts based upon a numerical solution of the Reynolds equation.Design/methodology/approachThe present paper proposes the mapping of the behaviour of a smooth, isothermal and hydrodynamic (j‐b) as a first step towards a future representation of the behaviour of j‐b's with limited length and high lubricating clearance with or without macro or micro topographic features operating under high loads, high temperatures and low linear velocities leading to conditions of mixed or boundary lubrication.FindingsThe derived analytical relationships between dimensionless quantities lead to the development of high precision synthetic operational charts regarding sliding j‐b of any given geometry and varying operational characteristics.Originality/valueBy considering the iso‐operational curves which are of a hook form relevant to comparative data becomes directly and rapidly clarified.

Pseudospectral Orbit Simulation of Nonideal Gas-Lubricated Journal Bearings for Microfabricated Turbomachines

1999 ◽  
Vol 121 (3) ◽  
pp. 604-609 ◽  
Author(s):  
E. S. Piekos ◽  
K. S. Breuer
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Published Data ◽  
Simulation Tool ◽  
Orbit Method ◽  
Nonideal Gas ◽  
Stability Chart ◽  
Bearing Design

A journal bearing simulation tool developed to aid the design of the MIT microturbo-machine bearings is described. This tool uses an orbit method with a pseudospectral technique for treating the Reynolds equation. Comparison is made to various published data. Two types of stability chart are presented and their application to turbo-machine bearing design is discussed. Simulations of imbalance, noncircular geometry, and nonuniform pressures at the bearing ends are also demonstrated.

A Review of Journal Bearing Thermal Effects on Rotordynamic Response

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Dongil Shin ◽  
Jongin Yang ◽  
Xiaomeng Tong ◽  
Junho Suh ◽  
Alan Palazzolo
Keyword(s):  
Thermal Effects ◽  
High Performance ◽  
Thermal Instability ◽  
Reynolds Equation ◽  
Dynamic Properties ◽  
Critical Role ◽  
Journal Bearings ◽  
Constant Viscosity ◽  
Bearing Design ◽  
Dynamics Models

Abstract Traditional analysis of journal bearings assumed a constant viscosity which simplified the solutions for static and dynamic characteristics and responses. Today's high-performance machinery requires more accurate models wherein temperature and viscosity distributions in the film must be calculated. Thermal effects in journal bearings have a strong influence on both static and dynamic properties, and consequently play a critical role in determining rotor-bearing system performance. This paper presents an extensive survey of the thermal modeling methods and effects in journal bearings. The subjects include various bearing types, and recent progress in thermal bearing design and thermal instability problems observed in fluid and gas film hydrodynamic bearings. The extent of the survey ranges from conventional Reynolds equation models to more advanced computational fluid dynamics models.

Bifurcation Analysis of Self-Acting Gas Journal Bearings

2001 ◽  
Vol 123 (4) ◽  
pp. 755-767 ◽  
Author(s):  
Cheng-Chi Wang ◽  
Cha’o-Ku`ang Chen
Keyword(s):  
Dynamic Behavior ◽  
Reynolds Equation ◽  
Rotational Velocity ◽  
Power Spectra ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Finite Differences Method ◽  
Subharmonic Response ◽  
Rotor Center ◽  
Rotor Mass

This paper studies the bifurcation of a rigid rotor supported by a gas film bearing. A time-dependent mathematical model for gas journal bearings is presented. The finite differences method and the Successive Over Relation (S.O.R) method are employed to solve the Reynolds’ equation. The system state trajectory, Poincare´ maps, power spectra, and bifurcation diagrams are used to analyze the dynamic behavior of the rotor center in the horizontal and vertical directions under different operating conditions. The analysis shows how the existence of a complex dynamic behavior comprising periodic and subharmonic response of the rotor center. This paper shows how the dynamic behavior of this type of system varies with changes in rotor mass and rotational velocity. The results of this study contribute to a further understanding of the nonlinear dynamics of gas film rotor-bearing systems.

A General Solution of Reynolds’ Equation for a Full Finite Journal Bearing

1967 ◽  
Vol 89 (2) ◽  
pp. 203-210 ◽  
Author(s):  
R. R. Donaldson
Keyword(s):  
Fourier Series ◽  
Series Solution ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Separation Of Variables ◽  
Hill Equation ◽  
Eigenvalues And Eigenvectors ◽  
General Series ◽  
Bearing Load

Reynolds’ equation for a full finite journal bearing lubricated by an incompressible fluid is solved by separation of variables to yield a general series solution. A resulting Hill equation is solved by Fourier series methods, and accurate eigenvalues and eigenvectors are calculated with a digital computer. The finite Sommerfeld problem is solved as an example, and precise values for the bearing load capacity are presented. Comparisons are made with the methods and numerical results of other authors.

The Effect of Journal Bearing Misalignment on Load and Cavitation for Non-Newtonian Lubricants

1986 ◽  
Vol 108 (4) ◽  
pp. 645-654 ◽  
Author(s):  
R. H. Buckholz ◽  
J. F. Lin
Keyword(s):  
Reynolds Equation ◽  
Numerical Solutions ◽  
Journal Bearings ◽  
Surface Boundary ◽  
Film Rupture ◽  
Aspect Ratios ◽  
Free Surface Boundary Condition ◽  
Load Carrying ◽  
Boundary Location ◽  
Surface Boundary Condition

An analysis for hydrodynamic, non-Newtonian lubrication of misaligned journal bearings is given. The hydrodynamic load-carrying capacity for partial arc journal bearings lubricated by power-law, non-Newtonian fluids is calculated for small valves of the bearing aspect ratios. These results are compared with: numerical solutions to the non-Newtonian modified Reynolds equation, with Ocvirk’s experimental results for misaligned bearings, and with other numerical simulations. The cavitation (i.e., film rupture) boundary location is calculated using the Reynolds’ free-surface, boundary condition.

An Approximate THD Theory for Journal Bearings

1990 ◽  
Vol 112 (2) ◽  
pp. 224-229 ◽  
Author(s):  
G. Gupta ◽  
C. R. Hammond ◽  
A. Z. Szeri
Keyword(s):  
Journal Bearing ◽  
Load Capacity ◽  
Pressure Coefficient ◽  
Journal Bearings ◽  
Maximum Pressure ◽  
Substantial Agreement ◽  
Interactive Mode ◽  
Lubricant Flow ◽  
Bearing Load ◽  
Sophisticated Model

The aim of this paper is to make available to the industrial designer results of the thermohydrodynamic theory of journal bearings, by providing a simplified, yet accurate model of journal bearing lubrication that can be implemented on a personal computer and be used in an interactive mode. The simplified THD theory we propose consists of two coupled ordinary differential equations for pressure and energy and an algebraic equation for viscosity, which are to be solved iteratively. Bearing load capacity, maximum bearing temperature, maximum pressure, coefficient of friction and lubricant flow rate calculated from this simplified theory compare well with results from a more sophisticated model. We also make comparisons with experimental data on full journal bearings, demonstrating substantial agreement between experiment and simplified theory.

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