Abrasive Wear of Piston Grooves of Highly Loaded Diesel Engines

Volume 1 ◽  
2004 ◽  
Author(s):  
Nagaraj Nayak ◽  
P. A. Lakshminarayanan ◽  
M. K. Gajendra Babu ◽  
A. D. Dani
Keyword(s):  
Abrasive Wear ◽  
Diesel Engines ◽  
Cylinder Pressure ◽  
Oil Consumption ◽  
Depth Of Penetration ◽  
Groove Surface ◽  
Air Filter ◽  
Abrasive Particles ◽  
Hard Particles ◽  
Peak Cylinder Pressure

The rate of wear of piston grooves on the piston is mainly a function of the peak cylinder pressure, hardness, surface roughness, depth of penetration and the number of hard particles produced by combustion or entering past the air filter. The problem of wear becomes severe as the blowby past the rings and oil consumption of the engine increases in diesel engines. In this paper, an attempt is made to estimate the wear of piston grooves quantitatively. The wear rate is correlated with the product of gaseous load, amount of hard particles past the piston lands, radius of abrasive particles, and inversely with hardness of the groove surface. Under abnormal conditions, the shear strain due to friction exceeds the plasticity limit of the material and superficial delamination occurs at the groove surface. The model was validated on a large bore engine running on heavy fuel at 22-bar bmep and the abrasive wear predicted by other earlier models are discussed [7].

Bore Polishing Wear in Diesel Engine Cylinders

Volume 1 ◽  
2004 ◽  
Author(s):  
Nagaraj Nayak ◽  
P. A. Lakshminarayanan ◽  
M. K. Gajendra Babu ◽  
A. D. Dani
Keyword(s):  
Cylinder Liner ◽  
Engine Oil ◽  
Cylinder Pressure ◽  
Oil Consumption ◽  
Depth Of Penetration ◽  
Wear Model ◽  
Carbon Particles ◽  
Peak Cylinder Pressure ◽  
Study Results

The rate of wear of the cylinder liner is mainly a function of peak cylinder pressure, the depth of penetration of hard carbon particles ingress during abusive running conditions. The problem of wear becomes severe as the blowby past the rings and the oil consumption of an engine increases in diesel engines. In this paper, a methodology is developed to estimate the wear of liner due to bore polishing action. The wear rate is correlated with the product of gaseous load, contact stress, and sliding action of the piston surfaces. Under abnormal conditions, the shear strain due to friction exceeds the plasticity limit of the material, superficial delamination occurs at the liner surfaces. The wear model was validated on large engines running on heavy fuel at 22-bar bmep. The case study results showed that by modifying the piston profile and liner geometry, and bore polishing of the liner surfaces is reduced and the engine oil consumption rate is improved substantially.

scholarly journals Study of Using Oxygen-Enriched Combustion Air for Locomotive Diesel Engines

2000 ◽  
Vol 123 (1) ◽  
pp. 157-166 ◽  
Author(s):  
D. N. Assanis ◽  
R. B. Poola ◽  
R. Sekar ◽  
G. R. Cataldi
Keyword(s):  
Oxygen Content ◽  
Diesel Engines ◽  
Oxygen Enrichment ◽  
Air Separation ◽  
Injection Timing ◽  
Full Potential ◽  
Cylinder Pressure ◽  
Peak Cylinder Pressure ◽  
Locomotive Diesel ◽  
No Emissions

A thermodynamic simulation is used to study the effects of oxygen-enriched intake air on the performance and nitrogen oxide (NO) emissions of a locomotive diesel engine. The parasitic power of the air separation membrane required to supply the oxygen-enriched air is also estimated. For a given constraint on peak cylinder pressure, the gross and net power output of an engine operating under different levels of oxygen enrichment are compared with those obtained when a high-boost turbocharged engine is used. A 4 percent increase in peak cylinder pressure can result in an increase in net engine power of approximately 10 percent when intake air with an oxygen content of 28 percent by volume is used and fuel injection timing is retarded by 4 degrees. When the engine is turbocharged to a higher inlet boost, the same increase in peak cylinder pressure can improve power by only 4 percent. If part of the significantly higher exhaust enthalpies available as a result of oxygen enrichment is recovered, the power requirements of the air separator membrane can be met, resulting in substantial net power improvements. Oxygen enrichment with its attendant higher combustion temperatures, reduces emissions of particulates and visible smoke but increases NO emissions (by up to three times at 26 percent oxygen content). Therefore, exhaust gas after-treatment and heat recovery would be required if the full potential of oxygen enrichment for improving the performance of locomotive diesel engines is to be realized.

scholarly journals Abrasive wear resistance of selected woods

2017 ◽  
Vol 63 (No. 2) ◽  
pp. 91-97
Author(s):  
Brožek Milan
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Sweet Cherry ◽  
Sour Cherry ◽  
Wear Intensity ◽  
Horse Chestnut ◽  
Silver Fir ◽  
Abrasive Particles ◽  
Volume Weight ◽  
Pin On Disk

In this contribution, the results of the wear resistance study of 10 sorts of wood (apple, aspen, beech, hornbeam, horse-chestnut, London plane, mahogany, silver fir, sour cherry and sweet cherry) are published. The laboratory tests were carried out using the pin-on-disk machine when the abrasive clothes of three different grits (240, 120 and 60) were used. The wear intensity was assessed by the volume, weight and length losses of the tested samples. From the results of the carried out tests it follows that the wear resistance of different woods is different. It was proved that the wear resistance of different woods depends on the abrasive particles size, too. Also the technical-economical evaluation was part of the carried out tests. It was univocally proved that at the intensive abrasive wear using the abrasive cloth the best results were shown by hard woods, e.g. apple, beech or mahogany. Soft woods, e.g. horse-chestnut, silver fir or sweet cherry, are cheap, but their wear is bigger compared to hard woods.

A Signal Processing of In-Cylinder Pressure for the Resonant Frequency Prediction of Combustion Process in Diesel Engines

2018 ◽  
Author(s):  
Ximing Chen ◽  
Long Liu ◽  
Jiguang Zhang ◽  
Jingtao Du
Keyword(s):  
Signal Processing ◽  
Fourier Transform ◽  
Wavelet Transform ◽  
Resonant Frequency ◽  
Diesel Engines ◽  
Combustion Process ◽  
Combustion Noise ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Empirical Wavelet Transform

The combustion resonance is a focal point of the analysis of combustion and thermodynamic processes in diesel engines, such as detecting ‘knock’ and predicting combustion noise. Combustion resonant frequency is also significant for the estimation of in-cylinder bulk gas temperature and trapped mass. Normally, the resonant frequency information is contained in in-cylinder pressure signals. Therefore, the in-cylinder pressure signal processing is used for resonant frequency calculation. Conventional spectral analyses, such as FFT (Fast Fourier transform), are unsuitable for processing in-cylinder pressure signals because of its non-stationary characteristic. Other approaches to deal with non-stationary signals are Short-Time Fourier Transform (STFT) and Continue Wavelet Transform (CWT). However, the choice of size and shape of window for STFT and the selection of wavelet basis for CWT are totally empirical, which is the limit for precisely calculating the resonant frequency. In this study, an approach based on Empirical Wavelet Transform (EWT) and Hilbert Transform (HT) is proposed to process in-cylinder pressure signals and extract resonant frequencies. In order to decompose in-cylinder pressure spectrum precisely, the EWT are applied for separating the frequency band corresponding combustion resonance mode from other irrelevant modes adaptively. The signals containing combustion resonant mode is processed by HT, so that the instantaneous resonant frequency and amplitude can be extracted. Validation is performed by four in-cylinder pressure signals with different injection timing. And the effects of injection timing on resonant frequency are discussed.

Remote Combustion Sensing Methodology for Non-Intrusive Cylinder Pressure Estimation in Diesel Engines

2013 ◽  
Vol 46 (21) ◽  
pp. 353-359 ◽  
Author(s):  
Fabrizio Ponti ◽  
Vittorio Ravaglioli ◽  
Enrico Corti ◽  
Davide Moro ◽  
Matteo De Cesare
Keyword(s):  
Diesel Engines ◽  
Cylinder Pressure ◽  
Pressure Estimation
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