Figure 4 - available via license: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
Content may be subject to copyright.
Source publication
The problem with cavitation and possible pitting in internal combustion diesel engines is studied here. Both theoretical and numerical simulation studies are carried out in order to understand the noise and vibration sources using a force equation. Noise and vibration are modeled in both 2D and 3D using the finite element analysis software ANSYS. A...
Similar publications
This paper proposes an analysis of the spark ignition engine performance for the road vehicles. The intake, compression, combustion, expansion and evacuation processes are taken into account, being modelled according to the engine load, for several engine speed values, thus determining each of the pressure and temperature parameters. The model deve...
The objective of this study is a better understanding of all phenomena related to the persistence or the extinction of a flame stabilized over a solid material located in the upper zone of an open compartment vitiated by combustion products. Laboratory scale experiments are performed to determine the combustion behavior as a function both of the fi...
Resumen Se desarrolla un modelo numérico para representar el comportamiento sísmico de muros de albañilería sometidos a solicitación perpendicular a su plano, teniendo en cuenta su comportamiento no lineal. Para esto, se realiza una modificación al modelo numérico desarrollado previamente con el programa ANSYS (ANSYS, 2013) por Campbell (Campbell,...
Citations
... Nowadays, with the developing of computer-aided engineering, the numerical computation can be easily performed, such as the whole engine isolation vibration system model and its analysis [4]. In abroad, not only the piston slap, but also its effect on the cavitation of wet cylinder liner are the main research contents [5][6][7][8][9][10]. ...
An isolation system of diesel engine with cylinder gap was modeled to deeply study the effect of piston shock on the whole vibration system. With the diesel engine rotates at rated speed, the center of engine body mass moves in plane with an obvious ellipse, and the magnitude is enlarged high to 3.5 times of the origin. All the bottom three directional springs have the corresponding response with the fundamental frequency signal, and a characteristic frequency band, as the piston slap is considered.
... In those engines, the passage of the connecting-rod through the upper and lower dead centres in the cylinder generates vibrations of high frequency. They cause erosive damage -surface degradation of the cooled part of the liner due to cavitation in the cooling liquid [3,4,5,7,16] . Erosive degradation of the surface significantly lowers durability of the cylinder [9] liner and at the same time the hourly service life of the whole engine. ...
... Erosive degradation of the surface significantly lowers durability of the cylinder [9] liner and at the same time the hourly service life of the whole engine. An effective method of preventing erosion of the surface of chilled internal combustion engines is presented in [1,4], where for protection of metal cylinder liners and block mantle it is recommended to add chilled water containing nickel salts. The nickel layer well protects the metal from the impact of implosive gas-vapor bubbles [4]. ...
... An effective method of preventing erosion of the surface of chilled internal combustion engines is presented in [1,4], where for protection of metal cylinder liners and block mantle it is recommended to add chilled water containing nickel salts. The nickel layer well protects the metal from the impact of implosive gas-vapor bubbles [4]. However, it is not always possible to use this additive in cooled water due to the difficulty of its production. ...
This article presents the utilitarian need to determine the free vibrations of marine Diesel engine cylinder liners and the authors’ own studies in this area. Theoretical investigations on free vibrations and experimental ones on forced vibrations have been described. Theoretical studies have been conducted with the application of characteristic dimensionless numbers in the Elektroniks Workbench and Wis Sim digital environment enabling virtual modeling of cylinder liner vibrations and determination of their characteristics: amplitudes, frequencies and accelerations. In the theoretical examination mechanical and electrical system analogues have been applied. A calculation method for the cylinder liner vibration damper, developed as a result of the study, has been discussed. Electrical oscillation damping filter design methods basing on the Bessel, Batterword and Chebyshev polynomials have been used. The course of the experimental examinations has been described and their results have been presented. Validation of the developed method has been executed applying measurement results concerning the parameters of Diesel engine cylinder liner vibration with various elastic elements. The results of the authors’ own, theoretical and experimental, examinations have been confronted with those obtained by other scholars. © 2018, Polish Academy of Sciences Branch Lublin. All rights reserved.
In order to reduce the striking and lateral force between piston and wet cylinder liner of diesel engines as well as to curb the cavitation of the cylinder liner, the influence of the piston pin hole offset on cavitation was systematically investigated. The bench test was carried out by employing the six cylinder inline diesel engine with different offset of piston pin hole, then the surface and section of the cylinder liner were measured and observed. In addition, the kinetic energy of piston as well as the vibration acceleration of cylinder liner under different offset of piston pin hole were calculated by dynamic numerical simulation comparing with the corresponding characteristics of the secondary motion. The results showed that after 500 h of running under standard conditions, obvious cavities were found on the cylinder liner without any offset of piston which expanded rapidly. By contrast, a good surface condition was found in the scheme with an negative offset. Meanwhile, the kinetic energy of piston reduced monotonously when the offset of the pin hole increased from 0 to −1.2 mm. Precisely, the maximum of kinetic energy corresponding to −0.5 mm and −0.8 mm offsets decreased by 41% and 59% respectively. Although it was even lower at −1.2 mm, the corresponding friction loss rose significantly which was detrimental to the stable operation between piston and cylinder liner. In addition, the vibration acceleration of cylinder liner in each scheme also decreased monotonically with the increase of the absolute value of the negative offset of the piston pin hole with a faint amplitude of fluctuation. Therefore, an appropriate negative offset of the pin hole could effectively improve the impact of the secondary motion of piston on the cylinder liner so as to effectively impede the cavitation which lays the foundation for enhancing the stability of the engine.
