Development of a Three Dimensional Model of Wall Fuel Liquid Film for Internal Combustion Engines

1998 ◽  
Author(s):  
H. Foucart ◽  
C. Habchi ◽  
J. F. Le Coz ◽  
T. Baritaud
Keyword(s):  
Liquid Film ◽  
Internal Combustion Engines ◽  
Three Dimensional ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Dimensional Model ◽  
Three Dimensional Model

Nonlinear Transient Response of a High Speed Driven Valve System and Stresses in Valve Springs for Internal Combustion Engines

1989 ◽  
Vol 111 (3) ◽  
pp. 264-271 ◽  
Author(s):  
K. Nagaya
Keyword(s):  
High Speed ◽  
Internal Combustion Engines ◽  
Three Dimensional ◽  
Beam Theory ◽  
Internal Combustion ◽  
Valve Train ◽  
Combination Method ◽  
Combustion Engines ◽  
Valve System ◽  
Cam Profile

This paper presents a method for solving the dynamic response problems of a driven valve system and the stress problem of valve springs for internal combustion engines. In this system there is hysteresis behavior in the spring constants during the rotation of the cam shaft. To treat this nonlinearity, the rigidity of each section is assumed to be one of a partly linear spring. For the valve trains, the cam profile is complex in general. To treat a general cam profile, this paper applies a combination method of the Fourier expansion, the Laplace transform and the analytical connection methods, and gives a response of valve trains. This paper also presents a theoretical result for the stresses in the valve spring due to the motion of the valve train based on the three dimensional curved beam theory.

Integrated modelling of internal combustion engine intake and exhaust systems

2001 ◽  
Vol 215 (4) ◽  
pp. 495-506 ◽  
Author(s):  
O Chiavola
Keyword(s):  
Internal Combustion Engines ◽  
Gas Flow ◽  
Complex Geometry ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Integrated Modelling ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Exhaust Systems

This paper presents a new method to analyse the unsteady gas flow in both intake and exhaust systems of internal combustion engines. Such a method is based on the simultaneous use of a one-dimensional model applied to describe the phenomena in ducts, together with a lumped parameter scheme to investigate the cylinder or other volume behaviour, coupled with a three-dimensional model, able to guarantee detailed information on flow behaviour in complex geometry, retaining the advantages of all methods, accuracy as well as fast processing and high flow pattern resolution. The description of the one-dimensional model developed with an example of its application is presented. The integrated approach with the coupling procedure is then described. Finally the results of a multicylinder exhaust system simulation are illustrated.

A Three-Dimensional Analysis of Piston Ring Lubrication Part 1: Modelling

1995 ◽  
Vol 209 (1) ◽  
pp. 1-14 ◽  
Author(s):  
M-T Ma ◽  
E H Smith ◽  
I Sherrington
Keyword(s):  
Internal Combustion Engines ◽  
Piston Ring ◽  
Three Dimensional ◽  
Combustion Engines ◽  
Three Dimensional Model ◽  
Engine Design ◽  
Piston Ring Lubrication ◽  
Almost All ◽  
Theoretical Analyses ◽  
Lubrication Conditions

The study of piston ring lubrication in internal combustion engines has remained a very active area in tribology. Theoretical analyses have been developed by many researchers to predict the performance characteristics of piston rings, but almost all previous models established were based upon the assumption that ring/cylinder geometry was axisymmetric. This may not be adequate for modern-day engine design since it is well known that cylinder bores are not perfectly circular. They suffer radial distortions which arise for various reasons. In the current work, a three-dimensional model has been developed to account for the effects of bore out-of-roundness. In order to do this, the three-dimensional Reynolds equation was solved cyclically using the finite difference method in fully flooded lubrication conditions. In this part of the paper, the theoretical model is presented and the effect of bore shape on piston ring performance is examined with three proposed types of bore (circular, elliptical and four-lobe). The results have shown that piston ring performance is significantly dependent on the bore shape or bore out-of-roundness.

Modeling the Lubrication, Dynamics, and Effects of Piston Dynamic Tilt of Twin-Land Oil Control Rings in Internal Combustion Engines

1999 ◽  
Vol 122 (1) ◽  
pp. 119-129 ◽  
Author(s):  
T. Tian ◽  
V. W. Wong
Keyword(s):  
Film Thickness ◽  
Internal Combustion Engines ◽  
Three Dimensional ◽  
Internal Combustion ◽  
Asperity Contact ◽  
Combustion Engines ◽  
Ring Groove ◽  
Oil Film ◽  
Oil Transport ◽  
Axial Forces

A theoretical model was developed to study the lubrication, friction, dynamics, and oil transport of twin-land oil control rings (TLOCR) in internal combustion engines. A mixed lubrication model with consideration of shear-thinning effects of multigrade oils was used to describe the lubrication between the running surfaces of the two lands and the liner. Oil squeezing and asperity contact were both considered for the interaction between the flanks of the TLOCR and the ring groove. Then, the moments and axial forces from TLOCR/liner lubrication and TLOCR/groove interaction were coupled into the dynamic equations of the TLOCR. Furthermore, effects of piston dynamic tilt were considered in a quasi three-dimensional manner so that the behaviors of the TLOCR at different circumferential locations could be studied. As a first step, variation of the third land pressure was neglected. The model predictions were illustrated via an SI engine. One important finding is that around thrust and anti-thrust sides, the difference between the minimum oil film thickness of two lands can be as high as several micrometers due to piston dynamic tilt. As a result, at thrust and anti-thrust sides, significant oil can pass under one land of the TLOCR along the bore, although the other land perfectly seals the bore. Then, the capabilities of the model were further explained by studying the effects of ring tension and torsional resistance on the lubrication and oil transport between the lands and the liner. The effects of oil film thickness on the flanks of the ring groove on the dynamics of the TLOCR were also studied. Friction results show that boundary lubrication contributes significantly to the total friction of the TLOCR. [S0742-4795(00)01801-9]

Three-dimensional thermohydrodynamic analysis of the effects of textured main bearing on lubricant density and viscosity in internal combustion engines

2021 ◽  
pp. 135065012110161
Author(s):  
Anvar Ahmadkhah ◽  
Amir H Kakaee
Keyword(s):  
Heat Transfer ◽  
Internal Combustion Engines ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Internal Combustion ◽  
Color Image Segmentation ◽  
Textured Surface ◽  
Combustion Engines ◽  
Bearing Surface ◽  
Feed Pressure

This paper is focused on the effects of the textured surface along with lubricant feed pressure and temperature variation to calculate the lubrication characteristics (viscosity and density) of the main bearings in internal combustion engines. In a three-dimensional numerical analysis simulation, a thermohydrodynamic model was developed, which considered the thermal effects of the fluid–solid interface components. In the analysis, the viscosity–temperature equation was used at different lubricant feed pressures and temperatures. By using color image segmentation methods, the density and viscosity contour on the two rotating walls (shaft and bearing wall) in the cavitation regions were quantitatively and qualitatively compared. The textured surface and lubricant feed pressure had significant effects on reducing the cavitation region over the shaft and bearing surface. Compared with the untextured bearing, the presence of texture over the bearing surface in the same temperature and pressure conditions increased the amount of total heat transfer to the lubricant fluid in the range of the maximum value of 73% and minimum value of 11%. Promoting the average heat transfer coefficient was a factor in reducing thermal stresses and high-temperature points in the rigid parts of the bearing system.

A Simple Theory for Pressure Pulses in Exhaust Systems

1964 ◽  
Vol 179 (1) ◽  
pp. 365-394 ◽  
Author(s):  
P. O. A. L. Davies ◽  
M. J. Dwyer
Keyword(s):  
Internal Combustion Engines ◽  
Three Dimensional ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Simple Method ◽  
One Dimensional ◽  
Flow Problems ◽  
Dimensional Flow ◽  
Dimensional Effects ◽  
Pressure Pulses

A simple method is presented for calculating the strength of pressure pulses transmitted through pipes with area changes or in simple branch systems. The method is based on the assumption of one-dimensional flow, otherwise the exact gas relations are employed. A number of examples of typical practical configurations were investigated both theoretically and experimentally and the results compared. With the exception of one or two cases where three-dimensional effects predominate, the agreement between the theory and the measurements was very satisfactory. The application of the theory to flow problems in internal combustion engines is discussed in some detail.

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