Alexandru Dima

Studies Regarding the Evolution of Pollutant Emissions Related to Certain Transitory Condition of an Internal Combustion Engine Using Mobile Measuring Systems

The internal combustion engine that equips a vehicle is a complex assembly of mechanical parts and electronics that controls almost every system. The electronic part of the vehicle gives the opportunity to observe and control what happens with the engine during function. The present paper follows the evolution of the pollutant emissions in relation with some transitory regimes of the car.

3D Model Based Process in Automotive Industry

The three dimensional design of modern auto vehicle through advanced virtual engineering methods is used from early development processes. From over 10 years automotive manufacturers’ have used 3D-CAD software packages following conventional development strategies of the product. These tools offer the possibility to design components through digital mock-up processes reducing time and errors in production. In this paper we evaluate the evolution of 3D-CAD based development processes based on geometry generation, conceptual design and simulations tools. The DMU method allows importing the 2D sketch in 3D software then creates a virtual model which can be optimized and analyzed.

Simulation of Air in the Intake Manifold Flap of an Internal Combustion Engine

The objective of this study is to analyze and predict the flow through the intake manifold using a computational fluid dynamics program (CFD). The performance of internal combustion engine depends of the intake manifold and its components. Three model of the intake manifold flap was created and analyzed by using the commercially available ANSYS software. The volumetric efficiency which affects the engine power and torque is affected by the flow of air in the intake manifold. These paper reviews the work realized by various researchers in the field of variable intake manifold. The CFD plots offers valuable information’s of the flow field and tension distribution in the various part of intake manifold flap mechanism. The results show that the CFD model can be used as a tool for improve and optimize various part of the intake manifold flap.

Evaluation of Thermistors Used for Temperature Measurement in Automotive Industry

Temperature sensors are widely used in different industrial and scientific applications. These sensors commercially available in various type and configurations allow the enhancement of automotive systems. The manufactures need to improve and upgrade the technology by research activities regarding the accuracy of temperature measuring using sensors. In this paper will analyze the trends, applications and technologies in automotive temperature sensors. PTC/NTC thermistors are measured and characteristics curves are determined as expression of mathematical functions.

Study of Emission of a Mono Cylindrical Diesel Engine Fueled with Biodiesel of Palm Oil

The demand of petroleum fuels which affect the air quality requires the use of alternative fuels to decrease the harmful emissions. In all the countries of European Union the biofuel production is stimulated and is a prime political and economic goal. The aim of this research is to evaluate the possibility to use biodiesel of palm oil in diesel engines with special emphasis on CO, CO2, HC and O2 emissions. Various blends of diesel and biodiesel of palm oil were mixed and evaluated on an experimental engine stand developed in the laboratory.

Different Approaches for Determination of Internal Combustion Engines Performances

The automotive industry represents one of the most important segments of the world economy that has to be in a continue development. The latest procedures for determination of an internal combustion engine performance have a big acquisition cost and demand special conditions even if the tested engine has smaller dimensions. The present paper presents other accessible solutions for this matter.

Considerations Regarding Validation through Simulation of Some Board System Information’s for Powertrain Performance Optimization

The authors present in this paper the opportunities offered by the use of software platforms (MULTISIM) in the validation of informational systems for optimizing economical consumption. So after some research (based on identification methodology system type) a physical-mathematical model can be developed that offers the possibility to optimize fuel consumption in the economy pole depending on specific correlations of operating regimes. Resulted relationships allow designing of information systems by proposing solutions which acquire information on movement speed, engine RPM in load (by determining the actual torque through correlations of exhaust gas temperature, moment and torque).Having these relationships we can design, for example, system version with discrete components or with digital system for surveillance engine operation.

Determination of Displacement of the Piece Center in the Process of Centerless Grinding

Chatter, geometric lobbing and work piece rotation problems are the main problems which affect the centerless grinding productivity. An original method was developed and implemented to determine the displacement of the centre of the piece in centerless grinding. Until now no functional tool has been developed to solve these coupled problems. In conclusion, future trends and research work in centerless grinding technology are analyzed and discussed.