Numerical Research on Tribological Performance of Textured Liner Surface Under Different Combustion Modes

Author(s):  
Bifeng Yin ◽  
Shao Sun ◽  
Bowen Wang ◽  
Yanqiang Qian

With the increasingly stringent requirements on energy saving and environmental-friendly for internal combustion (IC) engine, new concepts like novel combustion mode and surface texturing technology have emerged. In order to have deep understanding about the application effects of surface texturing into IC engine with new combustion mode, a mixed lubrication calculation model considering surface textures on cylinder liner together with different combustion modes has been built in the present work based on a four-cylinder diesel engine. The numerical research was conducted on the change of the surface tribological performance of textured cylinder liner under different combustion modes. The simulation results indicate that compared with the conventional combustion (CC) mode, the combustion phase of premixed charge combustion ignition (PCCI) mode and retarded injection (RI) mode varies and their in-cylinder peak pressure is different at the beginning of power stroke due to different injection strategies applied, which lead to significant differences between piston ring radial working loads. Near TDC, the mixed lubrication duration of PCCI and RI mode increases slightly in comparison to that of CC mode, and these three boundary lubrication durations are almost same. However, the thickness of lubricant film between friction pair of three modes is quite different, resulting in their different tribological properties. Among these parameters, the dimensionless total friction force (DTFF) and the dimensionless friction work of PCCI mode increase by 82.37% and 18.41% at most, respectively, while those of RI mode decrease by 36.50% and 12.45% at most, respectively, compared with the same parameters of CC mode. Therefore, the variations in tribological property of the textured cylinder liner–piston ring (CLPR) with different combustion modes should not be ignored.

2016 ◽  
Vol 18 (8) ◽  
pp. 785-796 ◽  
Author(s):  
Chunxing Gu ◽  
Xianghui Meng ◽  
Youbai Xie ◽  
Di Zhang

This article employs a mixed lubrication model to investigate the performance of the textured surface. The Jakobsson–Floberg–Olsson model is used to obtain the hydrodynamic support of the textured conjunction, while the calculation of the asperity contact load is based on the load-sharing concept. Based on the simulated Stribeck curves of the smooth surface and the textured surface, comparisons are conducted to study the effect of texturing under different lubrication regimes. It appears that the transition of lubrication regimes is influenced by the texturing parameters and the convergence degrees of conjunction. The presence of textures delays the appearance of the mixed lubrication regime and the boundary lubrication regime.


2017 ◽  
Vol 69 (2) ◽  
pp. 276-281 ◽  
Author(s):  
Feng Zhu ◽  
Jiujun Xu ◽  
Xiaoguang Han ◽  
Yan Shen ◽  
Mei Jin

Purpose The paper aims to investigate the friction and wear properties of three surface-modified piston rings matched with a chromium-plated cylinder liner. Design/methodology/approach Samples were taken from the chromium-plated cylinder liner, Cr-Al2O3 ring, CrN ring and Mo ring. Tribo-tests were conducted on a reciprocating sliding tribometer under fully formulated engine oils. Friction coefficients and wear depths of three friction pairs were tested. Surface morphologies of cylinder liners and piston rings before and after test were analyzed. Findings Experimental results show that in the Cr-Al2O3 piston ring, scuffing occurred easily when matched with the chromium-plated cylinder liner; compared with the Mo ring, the CrN ring could decrease the wear depth of the piston ring from 2.7 to 0.2 μm, and the wear depth of cylinder liner remained; however, the friction coefficient increased from 0.113 to 0.123. The tribological performances of three surface-modified piston rings were significantly different when they matched with chromium-plated cylinder liner. Originality/value Chromium-plated cylinder liner and the three kinds of surface-modified piston rings have excellent friction and wear properties, respectively. However, according to the systematic characteristics of internal combustion (IC) engine tribology, only the appropriate cylinder liner–piston ring can improve the tribological performance of the IC engine. This paper reports the tribological performance of three surface-modified piston rings matched with a chromium-plated cylinder liner. The results can be used as reference for the design of high-power-density diesel engine.


Author(s):  
Yang Hu ◽  
Xianghui Meng ◽  
Youbai Xie ◽  
Jiazheng Fan

The cylinder liner surface finish, which is commonly produced using the honing technique, is an essential factor of engine performance. The characteristics of the texture features, including the cross-hatch angle, the plateau roughness and the groove depth, significantly affect the performance of the ring pack–cylinder liner system. However, due to the influence of the honed texture features, the surface roughness of the liner is not subject to Gaussian distribution. To simulate the mixed lubrication performance of the ring–liner system with non-Gaussian roughness, the combination of a two-scale homogenization technique and a deterministic asperities contact method is adopted. In this study, a one-dimensional homogenized mixed lubrication model is established to study the influence of groove parameters on the load-carrying capacity and the frictional performance of the piston ring–liner system. The ring profile, plateau roughness, and operating conditions are taken into consideration. The main findings are that for nonflat ring, shallow and wide groove textures are beneficial for friction reduction, and there exists an optimum groove density that makes the friction minimum; for flat ring, wide and sparse grooves help improving the tribological performance, and there exists an optimum groove depth that makes the friction minimum.


Author(s):  
Chunxing Gu ◽  
Xianghui Meng ◽  
Shuwen Wang ◽  
Xiaohong Ding

In recent years, the efforts to better control friction and wear have focused on surface topography modification through surface texturing. To study the mutual influence of surface roughness and texture features, this paper developed one comprehensive mathematical model of mixed lubrication to study the tribological performance of the rough-textured conjunction. The typical ring-liner conjunction was chosen as the research object. In particular, the effects of skewness and kurtosis were considered based on the non-Gaussian distribution of asperity height. In this way, the influences of non-Gaussian distribution properties and surface texturing on the tribological performance were analyzed. The results show that the influences of skewness and kurtosis on the tribological performance are nontrivial and should not be neglected in the mixed lubrication. Compared to the Gaussian distribution, considering the non-Gaussian distribution can represent the physical rough surfaces more accurately. Surfaces with negative skewness were found to generally result in better tribological properties. Moreover, the tribological performance improved by surface texturing can also be improved or reduced by the effect of skewness and kurtosis. As a result, the optimization of surface texturing should take the effects of roughness parameters into account.


Author(s):  
Annadi Ramana Reddy ◽  
Syed Ismail

To enhance the tribological performance of mechanical parts, one of the reliable methods is surface topography modification, in which the surface of one/both interacting contacts were to be modified. Surface texturing is one of the surface modification techniques. In the present work, a numerical code is developed to address the effect of texture shape (elliptical and triangular), size and distribution (parallel and zigzag) on the tribological performance parameters (minimum film thickness, percentage of hydrodynamic load from the total generated pressure and frictional coefficient) under mixed lubrication regime for a known value of load support. In the present analysis, the mass conservative, i.e. Jakobson-Floberg-Ollson (JFO) cavitation condition and couple stresses of lubricant are considered. In addition, surface irregularities are considered by using the flow factors of Patir-Cheng model. The results show that texture shape has a significant effect, whereas the texture distribution has a slight effect on the tribological performance parameters. Moreover, the couple stress of lubricant has a prominent effect on the tribological performance.


2019 ◽  
Vol 71 (4) ◽  
pp. 515-524 ◽  
Author(s):  
Venkateswara Babu P. ◽  
Ismail Syed ◽  
Satish Ben Beera

Purpose In an internal combustion engine, piston ring-cylinder liner tribo pair is one among the most critical rubbing pairs. Most of the energy produced by an internal combustion engine is dissipated as frictional losses of which major portion is contributed by the piston ring-cylinder liner tribo pair. Hence, proper design of tribological parameters of piston ring-cylinder liner pair is essential and can effectively reduce the friction and wear, thereby improving the tribological performance of the engine. This paper aims to use surface texturing, an effective and feasible method, to improve the tribological performance of piston ring-cylinder liner tribo pair. Design/methodology/approach In this paper, influence of positive texturing (protruding) on friction reduction and wear resistance of piston ring surfaces was studied. The square-shaped positive textures were fabricated on piston ring surface by chemical etching method, and the experiments were conducted with textured piston ring surfaces against un-textured cylinder liner surface on pin-on-disc apparatus by continuous supply of lubricant at the inlet of contact zone. The parameters varied in this study are area density and normal load at a constant sliding speed. A comparison was made between the tribological properties of textured and un-textured piston ring surfaces. Findings From the experimental results, the tribological performance of the textured piston ring-cylinder liner tribo pair was significantly improved over a un-textured tribo pair. A maximum friction reduction of 67.6 per cent and wear resistance of 81.6 per cent were observed with textured ring surfaces as compared to un-textured ring surfaces. Originality/value This experimental study is helpful for better understanding of the potency of positive texturing on friction reduction and wear resistance of piston ring-cylinder liner tribo pair under lubricated sliding conditions.


1999 ◽  
Vol 123 (1) ◽  
pp. 211-218 ◽  
Author(s):  
Ozgen Akalin ◽  
Golam M. Newaz

An axi-symmetric, hydrodynamic, mixed lubrication model has been developed using the averaged Reynolds equation and asperity contact approach in order to simulate frictional performance of piston ring and cylinder liner contact. The friction force between piston ring and cylinder bore is predicted considering rupture location, surface flow factors, surface roughness and metal-to-metal contact loading. A fully flooded inlet boundary condition and Reynolds boundary conditions for cavitation outlet zone are assumed. Reynolds boundary conditions have been modified for non-cavitation zones. The pressure distribution along the ring thickness and the lubricant film thickness are determined for each crank angle degree. Predicted friction force is presented for the first compression ring of a typical diesel engine as a function of crank angle position.


2011 ◽  
Vol 4 (4) ◽  
pp. 1318-1324 ◽  
Author(s):  
Yin Bifeng ◽  
Li Xiaodong ◽  
Fu Yonghong ◽  
Wang Yun

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