Nicolae Vlad Burnete

Validation Procedure for Worldwide Harmonized Light Vehicles Test Cycle via Hardware in the Loop - Real Time Testing

This paper studies the behavior of a vehicle’s power-train model developed using IPG CarMaker software applications and connected to the testbed with IC Engine by Hardware in the Loop (HiL) real time testing methodology, for the homologation (due date 2017) driving cycle Worldwide Harmonized Light Vehicles Test Procedures (WLTP).

Studies Regarding the Influence of Exhaust Backpressure on the Performances of a Compression Ignited Engine

This paper presents some of the researches made on a compression ignited engine, in order to establish the influence of the exhaust backpressure (that can be caused by the existence or clogging of the catalytic converter, or by the SCR catalyst or the particle filter or by the noise reduction tubing itself) on the performances of a CI engine. The research was made on a ultramodern test bed inside the TestEcoCel Laboratory (Test, Research and Certification of Internal Combustion Engines) that work on biodiesel, of the Automotive and Transport Department, Technical University of Cluj-Napoca, Romania. Graphs, values and results were obtained through experimental measurements on the test bed and evaluated using specific software.

Re-sintering Influence on Tribological and Structural Characteristics of Iron-Based Composites for Automotive Applications

Iron-based sintered composites can be used for manufacturing different friction applications for the automotive industry (i.e. brake pads). The present research is a study concerning the influence of the re-sintering on the tribological and structural characteristics of three iron-based friction materials with application in vehicle brake systems. These composites were elaborated by powder metallurgy methods. The chemical composition of the materials contained iron, copper, graphite, nickel, titanium dioxide and/or barium carbonate. First, the three mixtures were homogenized. Green compacts were formed at a compaction pressure of 600 MPa. The sintering was done at 1050 °C, in vacuum for 30 min. The obtained samples were further re-sintered in vacuum, at 1050 °C for 20 min to improve their tribological characteristics. The elaborated materials were characterized by the tribological and structural point of view. The re-sintered samples presented, in general, a higher porosity than the sintered samples. An increase in the friction coefficient was marked out for all three re-sintered materials. Instead, a continuous increase or decrease in the wear rate was not observed. The material that contains titanium dioxide presented the best tribological properties in both sintered and re-sintered states.

Key fuel properties and engine performances of diesel-ethanol blends, using tetrahydrofuran as surfactant additive

In this paper there were presented researches related to preparation and characterization of physicochemical properties of diesel-ethanol blends stabilized with tetrahydrofuran as surfactant, in order to be used as fuels in compression ignition engines. The main spray characteristics and engine performances of these blends were evaluated by using AVL Fire software. In the first stage of the studies, commercial diesel was mixed with ethanol, in different concentrations (between 2% and 15% v/v), followed by the addition of tetrahydrofuran (THF) until the blends were miscible, i.e. the blends were stabilized. The experiments were done at room temperature (22 0C). The obtained blends were characterized in order to determine the chemical composition and physicochemical properties, i.e. density, kinematic viscosity, surface tension. UV-Vis spectroscopy was utilized in order to determine a semi-quantitative evaluation regarding the chemical composition of the prepared blends and chemical interaction between diesel, ethanol and THF. Based on the determined properties, the fuel spray characteristics, engine performances and emission characteristics were evaluated by simulation using the AVL Fire software. The obtained results regarding physicochemical properties of blends were compared with diesel. Some improvements were observed when operating with the prepared blends compared to diesel with respect to engine performances and emission characteristics. Based on physicochemical evaluation and computer simulation, it was demonstrated that diesel-ethanol-tetrahydrofuran blends can be used as alternative fuel in compression ignition engines.

Direct Injection of Diesel and Ethanol in a Diesel Engine - A Numerical Analysis

The objective of this study is to obtain an insight inside the combustion chamber of a Diesel engine running with a blend containing 90 % v/v Diesel and 10 % v/v Ethanol (D90E10) compared to pure Diesel (D100) operation. Since the experimental conditions are kept the same for both cases the simulation boundary conditions are almost identical. Following the calibration of the model and the analysis of in-cylinder images it was noted that the start of injection for the D90E10 case is slightly advanced while the total duration remains the same. Combined with an improved combustion this led to higher in-cylinder pressure and temperature values which increased the NO emissions. However, the soot emissions reduced.

The Effects of a Diesel-Ethanol Blend Without Additives on Diesel Engine Operation

The objective of this study is to establish the influence that a blend of 90 % v/v Diesel and 10 % v/v Ethanol without additives has on the operation of a Diesel engine. In order to address the blend stability issue, the temperature of the fuel was maintained at 35 °C. For the comparison with pure Diesel operation the same test conditions were applied. The acquired data showed an increase in engine performances (power, torque) due to an increased indicated mean effective pressure. The higher values of the pressure come from an improved combustion, a conclusion which is supported by the pollutants measured in the exhaust gas: lower CO and O2, higher CO2 and higher NOx (as a result of the increased combustion temperature). The engine efficiency increases slightly.

Experimental Research Regarding the Possibility of Biofuel Fumigation Supply Method on a Single Cylinder Compression Ignited Engine

Limits and specific disadvantages of using the conventional fossil fuels, as well as their high price for the individual customer and the environmental impact of their incomplete combustion are some of the main reasons for taking new steps in research and development of new recipes, materials and methods regarding the fuel supply for internal combustion engines. The present paper encompass the research developed at Automotive Engineering and Transports Department in Technical University from Cluj-Napoca regarding the innovative possibilities for biofuel supply in compression ignited engines by a fumigation method on a laboratory engine test bed. There were recorded and studied the engine speed, torque variation at different operating regimes. The obtained results from the conducted research are analyzed and discussed in close detail. The bio-fuel fumigation method is compatible with the available diesel engine and has a positive effect upon few behavior features in testing operation.

Experimental research made during a city cycle on the feasibility of electrically charged SI engines

The paper presents experimental research on performance improvements in a city cycle (operating mostly transient) of a compact class vehicle equipped with a turbocharged SI engine which had attached an electric charger, to improve engine response at low operational speeds. During tests, functional parameters, energy consumption of the electric charger and vehicle performances were measured while driving in two operating conditions: with active and inactive electric charger. The tests were carried out on a well-defined path, in the same driving style, by the same driver.