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Yu Y.-H.,Wuhan University of Technology | Yu Y.-H.,Key Laboratory of Marine Power Engineering and Technology | Chen J.,Wuhan University of Technology | Yang J.-G.,Wuhan University of Technology | And 2 more authors.
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering | Year: 2013

Features of applying support vector machine (SVM) to diesel engine fault diagnosis with small samples were discussed. The different levels of exhaust valve leakage in diesel engine were simulated in test laboratory. By combining parameter analysis method and wavelet packet analysis method to extract the sensitive fault characteristic parameters, the diagnosis model was established based on SVM. It is confirmed that the effective values in whose cycle, exhaust closed section and combustion section of the high-pass filtered cylinder head acoustic emission signals and the energy ratios of 3 frequency bands i.e. S2, S3 and S4, obtained by 3-level Daubechies8 wavelet packet decomposition can effectively indicate valve leakage faults, and the diagnosis model based on the six fault characteristic parameters can be used effectively to diagnose different level valve leakages and its classification performance is stable.


Guo Z.,Wuhan University of Technology | Guo Z.,Key Laboratory of Marine Power Engineering and Technology | Yuan C.,Wuhan University of Technology | Yuan C.,Key Laboratory of Marine Power Engineering and Technology | And 2 more authors.
Open Mechanical Engineering Journal | Year: 2012

Diesel engines have been widely used in various engineering applications. The performance of diesel engines is influenced greatly by the operation condition of the cylinder liner-piston ring. It is therefore crucial to investigate and assess the working condition of the cylinder liner-piston ring. Literature review indicated that there are few studies on this issue. Therefore, this study proposes a condition identification model for the cylinder liner-piston ring via fuzzy C-means clustering technique. The experiments of different surface treatment of cylinder and several typical fault modes were carried out using an internal combustion engine simulation tester. The fuselage vibration signals of the diesel engine were collected. The wavelet packet was then used to obtain the high frequency components of the vibration signal and extract its energy characteristics. The vibration identification model based on fuzzy C-means clustering has been established according to these characteristics. The analysis results show that the proposed model can identify the operating mode of cylinder liner-piston ring according to the vibration characteristics effectively. © Guo et al.; Licensee Bentham Open.


Wang L.,Wuhan University of Technology | Wang L.,Key Laboratory of Marine Power Engineering and Technology | Xiang Y.,Wuhan University of Technology | Xiang Y.,Key Laboratory of Marine Power Engineering and Technology
Applied Mechanics and Materials | Year: 2013

The fractal surface profile can usually be represented by WM function, A fractal dimension and a fractal roughness parameter are very important characteristic parameters in WM function. Usually, fractal scaling parameter γ was set to equal to 1.5, fractal dimension can be determined by the structure function method, but the accurately identification of the fractal roughness parameter is still a problem. In the present study, a simply numerical scheme with clear routine was developed to determine the fractal roughness parameter, and the fractal roughness parameter were recovered with reasonable accuracy from the numerically generated rough surface profile based WM function. © (2013) Trans Tech Publications, Switzerland.


Huang Q.,Wuhan University of Technology | Liu J.,Wuhan University of Technology | Zhang C.,Wuhan University of Technology | Zhang C.,Key Laboratory of Marine Power Engineering and Technology | And 2 more authors.
INTERNOISE 2014 - 43rd International Congress on Noise Control Engineering: Improving the World Through Noise Control | Year: 2014

With the improvement of the requirements of large ships to ship economy, the coupling dynamics problem of the ship propulsion shafting is particularly prominent. Theoretical method for propulsion shafting coupled vibration needs to be solved to improve the reliability of the propulsion shafting and raise the sailing performance of the ship. This paper mainly studies on the coupled torsional-longitudinal dynamics analytical theory and numerical simulation of the propulsion shafting. Different kindsof incentivescan cause different kinds of coupling responses. The changes of displacement and rotation angle caused by coupled torsional-longitudinal vibration of the propulsion shafting is studied by the finite element method. Through comprehensive analysis for the coupling response of the propulsion shafting under the condition of different applied loads individually and simultaneously, the research reveals the dynamics mechanism of coupled torsional-longitudinal vibration and puts forward the theoretical guidance for coupled torsional-longitudinal vibration of the propulsion shafting.


Sun X.,Wuhan University of Technology | Sun X.,Key Laboratory of Marine Power Engineering and Technology | Yan X.P.,Wuhan University of Technology | Yan X.P.,Key Laboratory of Marine Power Engineering and Technology | And 2 more authors.
Maritime-Port Technology and Development - Proceedings of the International Conference on Maritime and Port Technology and Development, MTEC 2014 | Year: 2015

A greater understanding of energy efficiency of ships is vital to reduce CO2 emissions. Previous studies have put more emphasis on ocean ships than inland river ones. In order to analyze the operational energy efficiency of inland river ships, and based on the resistance characteristics of different navigation environment factors, a main engine operational energy efficiency model was developed using the Energy Efficiency Operational Indicator (EEOI) as monitoring tool. The modeling and simulation, taking advantage of MATLAB/Simulink, were verified by the data on board. The EEOI model was simulated under different navigation environment conditions. The results showed that the EEOI of the case ship is lower than its sea-going counterpart, and it varies with the main engine speed significantly, the simulation also showed how the EEOI is influenced by navigation environment such as wind, wave and water current. © 2015 Taylor & Francis Group


Wu X.C.,Wuhan University of Technology | Wu X.C.,Key Laboratory of Marine Power Engineering and Technology | Wang Z.J.,Wuhan University of Technology
Advanced Materials Research | Year: 2014

The control and regulation of SOx emissions have become a global urgent problem for the environment protection. In the field of ocean and marine engineering, The International Maritime Organization (IMO) has formally passed the amendment of MARPOL 73/78 Annex VI in 2008 that clarified the deadline of requirements on SOx emissions limit. A limitation of 3.5%mm is strictly requested during 2012 to 2020. Hence the SOx emissions of marine diesel engines faces unprecedented challenges while effective control and regulation systems on the SOx emissions reduction are scarce in the existing ships. To meet the IMO's requirements, this paper has presented a novel seawater exhaust gas cleaning (EGC) system for the SOx emissions reduction of marine diesel engines. The post-combustion desulfurization technology was employed in the EGC system. The carbon ion and hydrogen ion contained in the seawater have been introduced into the EGC system to participant the reaction of desulfurization. The seawater EGC system has already been established in a real ship. Experiments have been carried out with the established seawater EGC system to comparatively analyze SOX emissions characteristics when burning different oil types, including heavy oil and light oil. The experiment results show that the newly established seawater EGC system can achieve satisfactory performance with a desulfurization efficiency of 88%. More important, the standard of the SOX emission limitation set by IMO has been met by using the proposed EGC system. © (2014) Trans Tech Publications, Switzerland.


Zhu J.,Wuhan University of Technology | Yang J.-G.,Wuhan University of Technology | Yang J.-G.,Key Laboratory of Marine Power Engineering and Technology | Sun B.,Wuhan University of Technology | And 2 more authors.
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering | Year: 2014

Experimental research using thermoelectric method monitoring diesel engine main journal bearing wear was conducted on slide bearing test rig and diesel bench. It is found that the measured thermoelectric signals are correlative to the friction intensity and rotational speed on the sliding bearing test rig. The thermoelectric effect and the weak signals generated by friction between eccentric rotor and sliding bearing are detectable. The thermoelectric signal peaks reflected the different cylinder ignition points on the engine test bench, so it can locate the wear positions of different main journal bearings. The main journal bearing thermoelectric signal peaks in dry friction condition stronger than those in boundary lubrication condition, and the thermoelectric signal peaks have a increasing trend with main journal bearing wear increase.


Zhao J.,Wuhan University of Technology | Zhao J.,Key Laboratory of Marine Power Engineering and Technology | Sheng C.,Wuhan University of Technology | Yuan C.,Wuhan University of Technology | And 2 more authors.
Chemical Engineering Transactions | Year: 2013

Ships are offshore transport or working platforms. We developed an internet-enabled fleet technical condition management system by making ship connected to shore-resided technical management center. Operational data are uploaded automatically to management center for data storage, condition monitoring, trending, analysis, statistics, trouble shooting, and make operation and maintenance decisions. For it possible to apply a single system to manage a whole fleet, several technical aspects should be standardized. Data is the most fundamental part including machinery operating parameters, alarms, failure modes, and some others. We individualize and code these data and make them standard across the whole fleet, on-board monitoring system capture operating parameters snapshot periodically and all alarms, code, package and upload them. The Fleet management center system is a WEB application; all functions of it are designed against data standard. When fully realized, most management functions can be automated, to improve reliability, availability and maintainability of the whole fleet. Copyright © 2013, AIDIC Servizi S.r.l.

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