Recent Advances in Diesel Engine Diagnostic Techniques

Dear Colleagues,

We are inviting submissions to a Special Issue of Energies on the subject area of “Recent Advances in Diesel Engine Diagnostic Techniques”. The diesel engine is known worldwide for its superior thermal efficiency compared to all other thermal engines and for its high reliability and availability. One critical issue is to keep the reliability and availability of diesel engines at high levels and at the same time to reduce maintenance cost and the time period the diesel engine is out of order for inspection and maintenance. Hence, predictive maintenance based on engine condition monitoring has been proven an effective means not only to evaluate the operational performance of diesel engines and to diagnose potential engine malfunctions or engine faults on time and, thus, to reduce maintenance time and cost but also to optimize diesel engine performance characteristics. Various diesel engine condition monitoring and diagnostic techniques have been proposed in the literature and have been used in engineering practice with different levels of effectiveness on tracking the main causes of diesel engine potential malfunctions or faults. These techniques are especially important for large diesel engines used for vessel propulsion and power generation due to their large size, which does not allow the application of trial and error techniques. Currently, the new generation of marine propulsion engines is electronically controlled, but as revealed from service experience, despite the large amount of information available from their control system, the need for developing and applying diagnosis techniques still exists.

One of the most common diagnostic techniques since the beginning of diesel engine application is the correlation of exhaust gas color and composition with specific faulty conditions. Another diagnostic method can be the correlation of specific engine component malfunctions or faulty situations with the measurement of specific gaseous and particulate emissions at various engine operating conditions, i.e., excessive smoke emissions can be related with faulty conditions of the fuel supply system and/or intake air system. Further, ferrographic and composition analysis of lubricant oil and the correlation of specific findings with specific diesel engine faulty situations is common practice in various diesel engine applications.

A modern efficient diesel engine diagnostic technique is based on the measurement of engine parameters such as in-cylinder pressure, engine torque, and intake air and exhaust gas system thermodynamic parameters and fuel flow measurements. One of the most effective and successful diesel engine diagnostic techniques is based on the measurement and processing of cylinder pressure and global engine thermodynamic parameters and settings related to fuel injection and inlet-exhaust systems. A similar approach is the use of engine simulators that provide information for global engine parameters, i.e., peak compression and firing pressure, scavenging air pressure, exhaust gas temperature, etc. This technique is based on the utilization of global parameters that can be measured using conventional instrumentation. The engine simulator is initially calibrated using data from official engine trials (i.e., shop tests), and then the procedure is repeated using actual data acquired on the field. The comparison of individual engine performance parameters between the “reference simulator” and the “current simulator” has been proven in many applications that provide indications for the main causes of specific faulty conditions not only on a qualitative basis, i.e., which engine component is faulty, but also on a quantitative basis. Obviously, the results in this case depend on the accuracy of the simulator used and the data that are available for the calibration of the engine simulator. Both techniques based on cylinder pressure measurement and its processing and on the use of an engine simulator based on phenomenological models can predict the time evolution of measured and simulated engine performance parameters, respectively, and correlate these tendency lines with the estimated time for targeted inspections and maintenance.

Other diagnostic techniques are based on the measurement and analysis of crankshaft torsional vibrations with various analysis methods ranging from classical ones such as the Holzer–Toller method and method of rotating vectors to more numerically advanced methods. Instantaneous angular speed (IAS) also contains a significant amount of for diesel engine fault diagnosis, and for this reason, various IAS signal analysis methods have been proposed since the early 1980s, ranging from fast Fourier transformation (FFT) to fuzzy systems, genetic algorithms, and artificial neural networks. Another means to identify engine faulty situations is the measurement and analysis on the frequency domain of mechanical vibrations of specific engine components and the potential correlation of measured signals with specific faulty mechanical signatures. Of particular importance for the characterization of fuel spray development, flame spread and intensity, in-cylinder gas velocity, and temperature distribution and pollutant formation are modern diesel combustion optical diagnostic techniques. Finally, recently, methods have been proposed in the literature for measuring and processing acoustic emissions from different engine components, such as fuel injection systems, and to perform diagnostic assessments. Further, nondestructive testing (NDT) methods such as ultrasonic sound analysis have been proposed for measuring and analyzing diesel engine combustion sound.

Consequently, all these diesel engine diagnostic techniques and potentially other revolutionary techniques offer a broad spectrum of tools for effective engine diagnosis, reduced maintenance time and cost, and engine performance optimization, which are quite important considering the degree of penetration of diesel engines in various transportation sectors and in the electric power generation sector.

Prof. Dr. Dimitrios Hountalas
Dr. Efthimios Pariotis
Dr. Theodoros Zannis
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• Cylinder pressure, and engine parameter measurement and analysis
• Cylinder pressure measurement and engine simulation
• Exhaust gas color and composition analysis
• Diesel-emitted pollutants measurement and analysis
• Diesel engine exhaust after-treatment systems diagnostics
• Shaft torsional vibrations measurement and analysis
• Instantaneous angular speed measurement and analysis
• Mechanical vibrations measurement and analysis
• Lubricant oil ferrography and composition analysis
• Acoustic emission measurement and analysis
• Nondestructive testing (NDT)—ultrasonic sound analysis
• Thermographic methods
• Diesel combustion optical diagnostics (Mie scattering, laser-induced fluorescence, Raman scattering, CARS, laser-induced incandescence)