scholarly journals Numerical analysis of piston ring pack operation

2009 ◽  
Vol 137 (2) ◽  
pp. 128-141
Author(s):  
Andrzej WOLFF
Keyword(s):  
Mathematical Model ◽  
Gas Flow ◽  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Labyrinth Seal ◽  
Piston Rings ◽  
Oil Film ◽  
Piston Ring Pack ◽  
Ring Pack

In the paper a model of a piston ring pack motion on an oil film has been analysed. The local oil film thickness can be compared to height of the combined roughness of mating surfaces of piston rings and cylinder liner. Equations describing the mixed lubrication problem based on the empirical mathematical model formulated in works of Patir, Cheng [6, 7] and Greenwood, Tripp [3] have been combined [12] and used in this paper. A model of a gas flow through the labyrinth seal of piston rings has been developed [13, 15]. In addition models of ring twist effects and axial ring motion in piston grooves have been applied [14, 15]. In contrast to the previous papers of the author, an experimental verification of the main parts of developed mathematical model and software has been presented. A relatively good compatibility between the experimental measurements and calculated results has been achieved. In addition this study presents the simulation results for an automobile internal combustion engine

scholarly journals Influence of piston ring pack configuration on blowby and friction losses in a marine two-stroke engine

2017 ◽  
Vol 170 (3) ◽  
pp. 164-170
Author(s):  
Andrzej WOLFF
Keyword(s):  
Gas Flow ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Labyrinth Seal ◽  
Piston Rings ◽  
Marine Engine ◽  
Oil Film ◽  
Flow Through ◽  
Piston Ring Pack ◽  
Ring Pack

In the paper a comprehensive model of a piston ring pack motion on an oil film has been presented. The local thickness of the oil film can be compared to height of the combined surface roughness of a cylinder liner and piston rings. Equations describing the mixed lubrication problem based on the empirical mathematical model formulated in works of Patir, Cheng and Greenwood, Tripp have been combined and used in this paper. In addition a model of gas flow through the labyrinth seal of piston rings has been developed. The main parts of the model and software have been experimentally verified abroad by the author at the marine engine designing centre. For the selected two-stroke marine engine, the influence of the number of piston rings used and the type of the top ring lock (straight or overlapped) on blowby to piston underside and on friction losses of the piston-ring-cylinder (PRC) system have been investigated. The developed model and software can be useful for optimization of the PRC system design

scholarly journals Mathematical Model of Piston Ring Sealing in Combustion Engine

2015 ◽  
Vol 21 (4) ◽  
pp. 66-78 ◽  
Author(s):  
Grzegorz Koszałka ◽  
Mirosław Guzik
Keyword(s):  
Mathematical Model ◽  
Heat Exchange ◽  
Numerical Solution ◽  
Gas Flow ◽  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Computer Application ◽  
Piston Rings ◽  
Flow Through

Abstract This paper presents a mathematical model of piston-rings-cylinder sealing (TPC) of a combustion engine. The developed model is an itegrated model of gas flow through gaps in TPC unit, displacements and twisting motions of piston rings in ring grooves as well as generation of oil film between ring face surfaces and cylinder liner. Thermal deformations and wear of TPC unit elements as well as heat exchange between flowing gas and surrounding walls, were taken into account in the model. The paper contains descriptions of: assumptions used for developing the model, the model itself, its numerical solution as well as its computer application for carrying out simulation tests.

The Prediction of Gas Pressures within the Ring Packs of Large Bore Diesel Engines

1981 ◽  
Vol 23 (6) ◽  
pp. 295-304 ◽  
Author(s):  
B. L. Ruddy ◽  
D. Dowson ◽  
P. N. Economou
Keyword(s):  
Gas Flow ◽  
Piston Ring ◽  
Angular Displacement ◽  
Cylinder Liner ◽  
Wall Friction ◽  
Piston Rings ◽  
Ring Pack ◽  
Piston Ring Lubrication ◽  
Volume Method ◽  
Gas Pressures

The established orifice and volume method for predicting the gas pressures between piston rings in reciprocating machines is extended to take account of the energy loss due to wall friction in the circumferential gas flow between the piston and cylinder liner. The results show that such energy losses are significant when gas flow rates exceed 10-2 kg/s and that this is most likely to occur in engines of over 0·5 m bore with worn piston rings. Under these conditions the angular displacement of the ring gaps significantly affects ring pack gas flow. In particular, it is shown that the maximum resistance to the flow of gas through the ring pack occurs when adjacent ring gaps are separated by more than 90 degrees. In the analysis of piston ring lubrication in ring packs it is necessary to ascertain the inter-ring pressures and the present paper enables such pressures to be determined with greater accuracy and for a wider range of engines.

scholarly journals Cylinder liner deformation orders and efficiency of a piston ring-pack

2019 ◽  
Vol 95 ◽  
pp. 04001 ◽  
Author(s):  
Erjon Selmani ◽  
Cristiana Delprete ◽  
Arian Bisha
Keyword(s):  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Order Zero ◽  
Gas Leakage ◽  
System A ◽  
Sealing Capacity ◽  
Mass Flows ◽  
Piston Ring Pack ◽  
Ring Pack

One of the several losses of a combustion chamber is the gas leakage toward the crankcase due to imperfect sealing of the rings. It is commonly known as blow by and it affects efficiency and emissions. The paper initially describes a bibliographic review of the phenomenon, together with the equations of the system. A typical piston ring pack for internal combustion engine is proposed to be analysed and solved using ©Ricardo RINGPAK Solver. A specific issue such as Bore distortion orders were used to investigate the sealing capacity of the ring-pack in terms of ring dynamics, inter-ring pressures and mass flows. Bore distortion orders and their magnitude showed to affect the ring pack behavior. Order zero distortion resulted to be the most important order due to the highest amount of gas lost in the crankcase, while orders three and four resulted to generate high blow-by values, even if their magnitude of distortion is lower in comparison to other orders.

Gas flow through the piston ring pack

2018 ◽  
Author(s):  
Petr Veigend ◽  
Gabriela Necasov ◽  
Peter Raffai ◽  
Vclav Åtek ◽  
Jir Kunovsk
Keyword(s):  
Gas Flow ◽  
Piston Ring ◽  
Flow Through ◽  
Piston Ring Pack ◽  
Ring Pack

Modeling Oil Evaporation From the Engine Cylinder Liner With Consideration of the Transport of Oil Species Along the Liner

2005 ◽  
Author(s):  
Liang Liu ◽  
Tian Tian ◽  
Ertan Yilmaz
Keyword(s):  
Piston Ring ◽  
Gasoline Engine ◽  
Cylinder Liner ◽  
Oil Composition ◽  
Evaporation Model ◽  
Engine Cylinder ◽  
Piston Ring Pack ◽  
Ring Pack ◽  
Model Oil ◽  
Engine Cylinder Liner

To estimate oil evaporation from an engine cylinder liner, an evaporation model has been implemented and incorporated with an existing 3-D piston ring-pack lubrication model. In this evaporation model, oil is modeled as being composed of distinct hydrocarbon species. Due to the depletion of light species and temperature variation, oil composition changes with space and time. Great emphasis was placed on the change of oil composition caused by oil transport through the ring-pack movement along the liner. The model was applied to a gasoline engine, and it was demonstrated that due to the movement of piston ring-pack, oil can be transported from the lower liner region to the upper liner region during the compression stroke, which gives a continuous supply of light species for oil evaporation.

First Paper: Measurement of the Oil-Film Thickness between the Piston Rings and Liner of a Small Diesel Engine

1974 ◽  
Vol 188 (1) ◽  
pp. 253-261 ◽  
Author(s):  
G. M. Hamilton ◽  
S. L. Moore
Keyword(s):  
Diesel Engine ◽  
Film Thickness ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Piston Rings ◽  
Oil Film

A capacity gauge has been designed for operating in the conditions of a working engine. The method of using it for determining the oil-film thickness and piston-ring profile is described. Oil-film thicknesses in the range 0·4-2·5 μm between the piston rings and the cylinder liner have been observed. Their variation with speed, load and temperature has been measured and it is concluded that their behaviour is essentially hydrodynamic.

A study of the influences of particles in the gas flow passage of a piston ring pack on the tribological performances of the piston ring

2009 ◽  
Vol 224 (1) ◽  
pp. 201-215 ◽  
Author(s):  
F-M Meng ◽  
J-X Wang ◽  
K Xiao
Keyword(s):  
Friction Force ◽  
Gas Flow ◽  
Piston Ring ◽  
Maximum Shear Stress ◽  
Gas Pressure ◽  
Von Mises Stress ◽  
Flow Passage ◽  
Particle Effect ◽  
Piston Ring Pack ◽  
Ring Pack

The influences of particles in the gas flow passage of a piston ring pack on the tribolo-gical performances of rings were numerically investigated based on a modified blow-by equation incorporating the particle effect and associated equations. Meanwhile, the particle effect on the blow-by of rings, inter-ring gas pressure, friction force, stresses, pressure, and deformation of the ring was solved by the Runge—Kutta method and the fast Fourier transform (FFT) technique. The numerical results show that obvious changes in the blow-by of the ring and the inter-ring gas pressure can occur if the particle effect is considered. The effect depends on the combined effect of the area, position, and number of particles. Meanwhile, the friction force of the top face of the ring, and the maximum Von Mises stress of the inner ring surface, contact pressure, deformation, and maximum shear stress of the contacting surface of the ring can obviously increase because of the particle effect.

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