scholarly journals An Investigation into the Acoustic Emissions of Internal Combustion Engines with Modelling and Wavelet Package Analysis for Monitoring Lubrication Conditions

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 640 ◽  
Author(s):  
Nasha Wei ◽  
James Gu ◽  
Fengshou Gu ◽  
Zhi Chen ◽  
Guoxing Li ◽  
...  
Keyword(s):  
High Performance ◽  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Acoustic Emissions ◽  
Internal Combustion ◽  
Power Stroke ◽  
Combustion Engines ◽  
Wide Range ◽  
Wavelet Package Analysis ◽  
Lubrication Conditions

Online monitoring of the lubrication and friction conditions in internal combustion engines can provide valuable information and thereby enables optimal maintenance actions to be undertaken to ensure safe and efficient operations. Acoustic emission (AE) has attracted significant attention in condition monitoring due to its high sensitivity to light defects on sliding surfaces. However, limited understanding of the AE mechanisms in fluid-lubricated conjunctions, such as piston rings and cylinder liners, confines the development of AE-based lubrication monitoring techniques. Therefore, this study focuses on developing new AE models and effective AE signal process methods in order to achieve accurate online lubrication monitoring. Based on the existing AE model for asperity–asperity collision (AAC), a new model for fluid–asperity shearing (FAS)-induced AE is proposed that will explain AE responses from the tribological conjunction of the piston ring and cylinder. These two AE models can then jointly demonstrate AE responses from the lubrication conjunction of engine ring–liner. In particular, FAS allows the observable AE responses in the middle of engine strokes to be characterised in association with engine speeds and lubricant viscosity. However, these AE components are relatively weak and noisy compared to others, with movements such as valve taring, fuel injection and combustions. To accurately extract these weaker AE’s for lubricant monitoring, an optimised wavelet packet transform (WPT) analysis is applied to the raw AE data from a running engine. This results in four distinctive narrow band indicators to describe the AE amplitude in the middle of an engine power stroke. Experimental evaluation shows the linear increasing trend of AE indicator with engine speeds allows a full separation of two baseline engine lubricants (CD-10W30 and CD-15W40), previously unused over a wide range of speeds. Moreover, the used oil can also be diagnosed by using the nonlinear and unstable behaviours of the indicator at various speeds. This model has demonstrated the high performance of using AE signals processed with the optimised WPT spectrum in monitoring the lubrication conditions between the ring and liner in IC engines.

A Novel Electromechanical Solution for Cam-Switching in High Performance Internal Combustion Engines

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli
Keyword(s):  
High Performance ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Valve Lift ◽  
Combustion Engines ◽  
Critical Aspect ◽  
Conceptual Design Phase ◽  
Common Strategy ◽  
Switch System

Abstract The variation of the valve lift is a fairly common strategy currently adopted in several in-service internal combustion engines to optimize their performance depending on the operating conditions of the vehicle. The most critical aspect to consider during the conceptual design phase of a cam switch system is the extremely narrow window of opportunity to perform the cam change, which duration is defined by the time during which the corresponding valve lift is null. To meet this requirement and ensure safe, repeatable movements, a novel architecture based on the combination of a new electromechanical actuator and its dedicated control system is presented. The architecture is at first introduced with reference to the numerous examples available in the literature, and hence mathematically described. The dynamic model of the system derived from the presented equation is then used to study the performance of the presented solution and define its control strategy. Results are finally presented and discussed.

scholarly journals Development and Validation of a Reduced DME Mechanism Applicable to Various Combustion Modes in Internal Combustion Engines

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Gregory T. Chin ◽  
J.-Y. Chen ◽  
Vi H. Rapp ◽  
R. W. Dibble
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Detailed Mechanism ◽  
Reduced Mechanism ◽  
Hcci Combustion ◽  
Combustion Modes ◽  
Reduced Chemistry ◽  
Wide Range ◽  
Development And Validation

A 28-species reduced chemistry mechanism for Dimethyl Ether (DME) combustion is developed on the basis of a recent detailed mechanism by Zhao et al. (2008). The construction of reduced chemistry was carried out with automatic algorithms incorporating newly developed strategies. The performance of the reduced mechanism is assessed over a wide range of combustion conditions anticipated to occur in future advanced piston internal combustion engines, such as HCCI, SAHCCI, and PCCI. Overall, the reduced chemistry gives results in good agreement with those from the detailed mechanism for all the combustion modes tested. While the detailed mechanism by Zhao et al. (2008) shows reasonable agreement with the shock tube autoignition delay data, the detailed mechanism requires further improvement in order to better predict HCCI combustion under engine conditions.

scholarly journals A research into a gasoline HCCI engine

2010 ◽  
Vol 140 (1) ◽  
pp. 3-13
Author(s):  
Jacek HUNICZ ◽  
Andrzej NIEWCZAS ◽  
Paweł KORDOS
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Hcci Combustion ◽  
Permissible Range ◽  
Wide Range ◽  
Gas Recirculation ◽  
Direct Fuel Injection

Homogeneous charge compression ignition (HCCI) is nowadays a leading trend in the development of gasoline internal combustion engines. The application of this novel combustion system will allow to comply with future legislations concerning the exhaust emissions including carbon dioxide. This paper presents a design and implementation of a research engine with a direct fuel injection and the capability of HCCI combustion via an internal gas recirculation and a negative valves overlap (NVO). The technical approach used in the engine allowed an autonomous HCCI operation at variable loads and engine speeds without the need of a spark discharge. Experiments were conducted at a wide range of valve timings providing data which allowed an assessment of a volumetric efficiency and exhaust gas recirculation (EGR) rate. Permissible range of air excess coefficient, providing stable and repeatable operation has also been identified. The use of direct gasoline injection benefited in the improvement of the start of the combustion (SOC) and heat release rate control via the injection timing.

scholarly journals Renewable Pulverized Biomass Fuel for Internal Combustion Engines

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 465
Author(s):  
Ashraf Elfasakhany ◽  
Mishal Alsehli ◽  
Bahaa Saleh ◽  
Ayman A. Aly ◽  
Mohamed Bassuoni
Keyword(s):  
Rate Constants ◽  
Internal Combustion Engines ◽  
Renewable Energy Sources ◽  
Internal Combustion ◽  
Solid Particles ◽  
Combustion Engines ◽  
Modeling Tools ◽  
Wide Range ◽  
New Phenomena ◽  
Powder Combustion

Biomass is currently one of the world’s major renewable energy sources. Biomass in a powder form has been recently proposed as the most encouraging of biomass contours, especially because it burns like a gas. In the current study, biomass powder was examined, for the first time, as a direct solid fuel in internal combustion engines. The aim of the current study was to investigate modeling tools for simulation of biomass powder in combustion engines (CE). The biomass powder applied was in a micro-scale size with a typical irregular shape; the powder length was in the range of 75−5800 μm, and the diameter was in the range 30−1380 μm. Different mechanisms for biomass powder drying and devolatilization/gasification were proposed, including different schemes’ and mechanisms’ rate constants. A comparison between the proposed models and experiments was carried out and results showed good matching. Nevertheless, it is important that a biomass powder simulation addresses overlapping/complicated sub-process. During biomass powder combustion, tar was shown to be formed at a rate of 57 wt.%, and, accordingly, the formation and thermal decomposition of tar were modelled in the study, with the results demonstrating that the tar was formed and then disintegrated at temperatures between 700 and 1050 K. Through biomass powder combustion, moisture, tar, and gases were released, mostly from one lateral of particles, which caused ejection of the solid particles. These new phenomena were investigated experimentally and modeled as well. Results also showed that all the proposed models, along with their rate constants, activation energies, and other models’ parameters, were capable of reproducing the mass yields of gases, tar, and char at a wide range of working temperatures. The results showed that the gasification/devolatilization model 3 is somewhat simple and economical in the simulation/computation scheme, however, models 1 and 2 are rather computationally heavy and complicated.

Method for controlling wave phenomena in highpressure line of common rail of internal combustion engines

2020 ◽  
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Internal Combustion ◽  
Common Rail ◽  
Combustion Engines ◽  
Multiple Injection ◽  
Multiple Injections ◽  
Fuel Supply ◽  
Injection Line ◽  
Wave Phenomena

The article presents an assessment of the dependence of the fuel supply on the wave phenomena in the highpressure line that occur during multiple injection. After injection, fluctuations in the fuel pressure in the fuel injection line occur, which significantly affect the cycle delivery and injection behavior of subsequent multiple injections. A promising design of a fuel rail is presented and a method for controlling wave phenomena in a highpressure line of a Common Rail is proposed. Keywords wave phenomena; multiple injection; Common Rail; electrohydraulic injector; fuel rail

STAND FOR RUNNING AND TESTING OF LOW POWER MOBILE FARM MACHINERY ENGINES

2016 ◽  
Vol 1 (2) ◽  
pp. 51-53 ◽  
Author(s):  
Иншаков ◽  
Aleksandr Inshakov ◽  
Байков ◽  
Dmitriy Baykov ◽  
Десяев ◽  
...  
Keyword(s):  
Low Power ◽  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
High Energy ◽  
Combustion Engines ◽  
Farm Machinery ◽  
Three Phase ◽  
Wide Range

The purpose of research is to improve the quality of production and repair internal low-power mobile farm combustion engines. To achieve this goal it was suggested to carry out running and testing the engines of small tools and equipment in specialized economical braking stands. The design of such stand, consisting of internal combustion engine, connected crank shaft with asynchronous electric machine with wound rotor, connected to the three-phase network, and matrix converter frequency included in the three-phase electrical network and consisting of nine bidirectional transistor switches, which receive signals space-vector control with automatic control system connected with the test equipment on the basis of a personal computer on which the signals from the sensors mounted on the internal combustion engine is also coming. This stand design for running and testing of internal combustion engines of mobile low power farm machinery is technically easy to manufacture and cost-effective to use. In addition, the design feature of the proposed technical solution is characterized by high energy efficiency and reliability, small dimensions and weight parameters, and wide range of speed control asynchronous machine with wound rotor.

A Cogging Torque Assisted Motor Driven Valve Actuation System for Internal Combustion Engines

2013 ◽  
Author(s):  
Bradley A. Reinholz ◽  
Rudolf J. Seethaler
Keyword(s):  
Internal Combustion Engines ◽  
High Efficiency ◽  
Acoustic Emissions ◽  
Internal Combustion ◽  
Performance Criteria ◽  
Combustion Engines ◽  
Cogging Torque ◽  
Actuation System ◽  
Stringent Performance ◽  
Valve Actuation

Electromechanical valve actuation (EVA) for internal combustion engines promises to significantly improve engine efficiency and lower emissions by reducing pumping losses and allowing for novel combustion strategies. However, current designs have not been able to meet the stringent performance criteria for reliability, efficiency, acoustic emissions, weight, and cost that are required by the automotive industry. This paper describes a novel cogging torque assisted motor driven (CTAMD) valve actuation system that promises to meet both the performance and robustness requirements. In contrary to existing EVA systems that recover the kinetic valve energy using a mechanical spring system, the CTAMD system recovers kinetic energy in a magnetic field. This allows for high efficiency while maintaining a simple and elegant electromechanical design. This paper describes the characteristics of CTAMD systems and outlines an electromechanical design for such a system. Then computer simulations of the proposed design are used to demonstrate the expected performance of the system. Finally, the simulated results are compared to other EVA systems to highlight the anticipated improvements.

Sign in / Sign up

Export Citation Format

Share Document