Starvation in Dynamically Loaded Flexible Short Journal Bearings

1985 ◽  
Vol 107 (4) ◽  
pp. 516-521 ◽  
Author(s):  
L. van der Tempel ◽  
H. Moes ◽  
R. Bosma
Keyword(s):  
Differential Equations ◽  
Numerical Method ◽  
Dynamic Load ◽  
Journal Bearings ◽  
Important Application ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Supply Pressure ◽  
Continuity Equations ◽  
Medium Speed

A starvation model is incorporated in a previously presented numerical method for calculating film thicknesses inflexible short journal bearings under dynamic load. The system of elastohydrodynamic integro-differential equations is now coupled with continuity equations for the lubricant, considering central circumferential oil grooves and a constant supply pressure. An important application of this method is the connecting rod bearing in medium speed combustion engines. Results for several groove geometries are compared with those for a fully flooded bearing.

Numerical Simulation of Dynamically Loaded Flexible Short Journal Bearings

1985 ◽  
Vol 107 (3) ◽  
pp. 396-401 ◽  
Author(s):  
L. van der Tempel ◽  
H. Moes ◽  
R. Bosma
Keyword(s):  
Numerical Simulation ◽  
Differential Equations ◽  
Numerical Method ◽  
Dynamic Load ◽  
High Speed ◽  
Journal Bearings ◽  
Combustion Engines ◽  
Dynamically Loaded ◽  
Newton Raphson ◽  
Raphson Method

A numerical method is proposed for calculating film thicknesses in flexible short journal bearings under dynamic load. The system of elastohydrodynamic integro-differential equations is discretized directly and solved by a 2-step Newton-Raphson method. The cavitation boundaries are located by a special discretization of the pressure. This type of condition puts practically no restrictions on the boundary alterations. The results for the con rod bearings of medium- and high-speed combustion engines are compared.

Steady-state modelling method for matrix-reactance frequency converter with boost topology

2011 ◽  
Vol 60 (2) ◽  
pp. 137-148
Author(s):  
Igor Korotyeyev ◽  
Beata Zięba
Keyword(s):  
Fourier Series ◽  
Steady State ◽  
Differential Equations ◽  
Numerical Method ◽  
Frequency Converter ◽  
Double Fourier Series ◽  
Galerkin’S Method ◽  
Galerkin's Method ◽  
Modelling Method ◽  
Three Phase

Steady-state modelling method for matrix-reactance frequency converter with boost topologyThis paper presents a method intended for calculation of steady-state processes in AC/AC three-phase converters that are described by nonstationary periodical differential equations. The method is based on the extension of nonstationary differential equations and the use of Galerkin's method. The results of calculations are presented in the form of a double Fourier series. As an example, a three-phase matrix-reactance frequency converter (MRFC) with boost topology is considered and the results of computation are compared with a numerical method.

Machine learning-based performance analysis of two-axial-groove hydrodynamic journal bearings

2021 ◽  
pp. 135065012199289
Author(s):  
Biswajit Roy ◽  
Sudip Dey
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Hydrodynamic Performance ◽  
Support Vector ◽  
Oil Viscosity ◽  
Hydrodynamic Analysis ◽  
Supply Pressure ◽  
Input Parameters ◽  
Precise Prediction ◽  
Output Behavior

The precise prediction of a rotor against instability is needed for avoiding the degradation or failure of the system’s performance due to the parametric variabilities of a bearing system. In general, the design of the journal bearing is framed based on the deterministic theoretical analysis. To map the precise prediction of hydrodynamic performance, it is needed to include the uncertain effect of input parameters on the output behavior of the journal bearing. This paper presents the uncertain hydrodynamic analysis of a two-axial-groove journal bearing including randomness in bearing oil viscosity and supply pressure. To simulate the uncertainty in the input parameters, the Monte Carlo simulation is carried out. A support vector machine is employed as a metamodel to increase the computational efficiency. Both individual and compound effects of uncertainties in the input parameters are studied to quantify their effect on the steady-state and dynamic characteristics of the bearing.

An implicit multistep numerical method for real-time simulation of stiff systems

SIMULATION ◽  
2021 ◽  
pp. 003754972110216
Author(s):  
Zhang Lei ◽  
Li Jie ◽  
Wang Menglu ◽  
Liu Mengya
Keyword(s):  
Differential Equations ◽  
Numerical Method ◽  
Real Time ◽  
Physical System ◽  
Physical Models ◽  
Stiff Systems ◽  
Real Time Simulation ◽  
Stiff Ordinary Differential Equations ◽  
Root Finding ◽  
Time Simulation

Simulating a physical system in real-time is widely used in equipment design, test, and validation. Though an implicit multistep numerical method excels at solving physical models that are usually composed of stiff ordinary differential equations, it is not suitable for real-time simulation because of state discontinuity and massive iterations for root finding. Thus, a method based on the backward differential formula is presented. It divides the main fixed step of real-time simulation into limited minor steps according to computing cost and accuracy demand. By analyzing and testing its capability, this method shows advantage and efficiency in real-time simulation, especially when the system contains stiff equations. A simulation application will have more flexibility while using this method.

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