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  • Author: Mate Zoldy x
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Detailed Modelling of the Internal Processes of an Injector for Common Rail Systems

Abstract

In the last few decades exhaust emissions of road vehicles have decreased dramatically, owing to the more and more stringent emission standards issued by the legislative bodies of different countries, combined with the necessity of cleaner, better performing vehicles from society side. The introduction of Common Rail (CR) injection systems has been a great step towards achieving this target, thanks to its flexibility in fuel injection pressure, timing, and length, along variable engine load conditions. However, it is highly time and resource consuming to set up the injection system for all operating points of different engines, moreover, as the injection is a small scale, high speed process, the behaviour of the internal processes is challenging to measure. The best solution for these problems is to create a detailed model of the injector, where all the hydraulic, mechanic, and electromagnetic subsystems are represented, this way the internal working conditions can be analysed and resources can be saved.

In this work, a detailed model of a first generation CR injector for commercial vehicles is presented and validated against needle lift data. The fluid dynamic and mechanic sub-systems are presented in details to thoroughly investigate the working principles of the injector internal parts. The fluid dynamic subsystem contains the chambers, holes, and throttles of the injector, while the mechanic subsystem models the motion and behaviour of the internal parts. The main features of the injector internal working conditions are described and analysed. Apart from the needle lift, these included solenoid anchor, pin and control piston lifts, the control chamber pressure and the mechanical force acting on the anchor. Five test cases were chosen on a medium duty test engine to represent a wide range of operation points from full load to idle and the simulated results were compared to the measured data. The simulated control piston movement accurately matched the measured curves in every test case.

Open access
Influence of External Environmental Factors on Range Estimation of Autonomous Hybrid Vehicles

Abstract

During our research, we focus on a less researched area in the development of autonomous vehicles. Automotive industry is turning more and more from conventional, internal combustion engine equipped vehicles to the electric cars. Today, electric driving is mostly limited to urban traffic, this is the area where range and refueling limits can be a real alternative. However, it is important to think of those who intend to use vehicle in longer distances, and hybrid technology can provide them a modern, environmentally conscious way of transport.

In this article, we describe the method of creating the fuel consumption influencing factors matrix, which is the starting point of our research. We studied relevant researches and based on refueling studies we created the matrix. Based on results of real tests, we determined the factor mix that are the basis of our fuel consumption prediction model. These results will be inputs of planning routes of autonomous vehicles with optimized refueling and fuel consumption.

Open access
Effects of Renewable Energy Sources on Air-Fuel Ratio

Abstract

Environmental emission of road transport is a key problem. Periodic environmental test are designed to ensure minimum emission. Periodic checks are based on measurements. In this emission measurements fuel type plays an important role. The Brettschneider equation is a method used to compare the idealized and actual air fuel ratio. Brettschneider established a method to calculate ratio of oxygen to fuel by comparing the ratio of oxygen molecules to carbon and hydrogen molecules in the exhaust. In this article, authors have investigated blended ethanol effect on idealized and actual air fuel ratio based on Brettschneider equation. The main result of the article that blended ethanol has insignificant effect on air-fuel ratio. The article presents inter alia difference in stoichiometric air fuel ratios in case of different fuels, changes in λ due to blending ethanol and comparison of influence of emissions of different types of transport. In the article authors focus particularly on periodic checks and gasoline driven cars. The main research question was if ethanol blends have effect on idealized and actual air fuel ratio based on Brettschneider equation.

Open access
Automatization in road transport: a review

Abstract

In this article automatization of road transport is investigated. In the first chapter relevant international trends were identified. In this paper the research hypothesis is that in the case of automatized road vehicles there is a significant likelihood of endangering human life. Secondly, the history of road safety is shortly described, especially focusing on vehicle design and sweep of system’s theory. In the third chapter evolution of drivers’ assistance systems were elaborated, emphasizing especially autonomous vehicles. Finally, in conclusion the authors warn that new technological solutions could pose new threats.

Open access