Dragos Tutunea

Human Head-Neck System Behavior during Virtual Impact Automotive Simulations

The paper presents the studies made on a similar biomechanical system composed by neck, head and dummy body components. The models were defined in a CAD environment which includes Adams algorithm for dynamic simulations. After simulation was obtained the entire mechanical behavior based on data tables or diagrams. That virtual model composed by neck and head was included in complex system (as a car system) and supposed to impact simulations (virtual crash tests). This paper presents issues concerning the use of CAD systems in modern technology virtual prototyping, in this case a complex virtual model for a car system used for impact simulations. Virtual prototyping is a process that uses a virtual prototype instead of the physical prototype for testing and evaluating specific elements of the designed product. Virtual prototype is created on the computer closer to the actual characteristics and operating conditions so as to allow the simulation to perform the role for which it was designed. The three-dimensional model has been exported into simulation software able to perform kinematics simulations and finite element analysis, at the same time. With that virtual model were analysed different situations similar with car crash. Results of simulations have been analysed and can be compared with measurements made on the experimental device (under construction).

Biodiesel Production and Sustainability Challenge

Today, energy is an indispensable factor for the developing of the societies and countries. However, most of the energy demand is supplied by fossil fuels which tend to dry up in the next few decades forcing all the authorities to find new alternative sources in order to stabilize their economies. Biodiesel has emerged as an alternative, biodegradable and renewable fuel which can be used in transportation sector without any modifications of internal combustion engines. Biodiesel is analyzed by environmental, social and economic criteria for sustainability analysis. The criteria for biodiesel sustainability are discussed by presenting different indicators, keeping in view the Romanian fuel market and Renewable energy directive. The paper concludes with perspectives and recommendations for biodiesel production and usage in Romania.

Characterization of Sunflower Oil Biodiesel as Alternative for Diesel Fuel

Methyl esters from various vegetable oils have been increasingly used in diesel engines to partially substitute or replace petroleum fuels. In this present study biodiesel was produced from sunflower oil by base-catalyzed transesterification process. A 30 L per batch experimental installation was used to produce biodiesel using a molar ratio of alcohol to oil 6:1, a reaction temperature of 65 °C and a reaction time of 2 h. A characterization and quality evaluation were done by measuring viscosity, flash point, density, fatty acid compositions, elementary and thermal analysis of sunflower oil, sunflower oil biodiesel and petroleum fuel. The results show poor atomization due to the high viscosity with the increase of combustion chamber deposits. Biodiesel has less carbon and hydrogen content than diesel fuel. The process of volatilization for sunflower oil biodiesel initiates and finishes in temperatures that are much higher than diesel.

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.

CFD and Structural Analysis of the Intake Manifold Flap of an Internal Combustion Engine

The objective of this study is to analyze the flow filed in the intake manifold using Computational Fluid Dynamics (CFD). The main function of the intake manifold flap is to regulate the air flow and to uniformly distribute in the cylinders. If the air is distributed uneven to the engine the volumetric efficiency, power and fuel consumption is reduced. The finite element method can be used to optimize the throttle flap. The results in the simulation offer valuable information’s of the flow field in the throttle assembly. 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.

Analysis of performance and emissions of diesel engine using sunflower biodiesel

The world consumption of fossil fuels is increasing rapidly and it affects the environment by green house gases causing health hazards. Biodiesel is emerging as an important promising alternative energy resource which can be used to reduce or even replace the usage of petroleum. Since is mainly derived from vegetable oil or animal fats can be produce for large scale by local farmers offering a great choice. However the extensive utilization of the biofuels can lead to shortages in the food chain. This paper analyzed the sunflower methyl ester (SFME) and its blends as an alternate source of fuel for diesel engines. Biodiesel was prepared from sunflower oil in laboratory in a small biodiesel installation (30L) by base transesterification. A 4 cylinder Deutz F4L912 diesel engine was used to perform the tests on various blends of sunflower biodiesel. The emissions of CO, HC were lower than diesel fuel for all blends tested. The NOx emissions were higher due to the high volatility and high viscosity of biodiesel.

Simulation of a Mono Cylindrical Engine with LES Software

This paper analyzes the numerical research carried out on a single-cylinder research engine. 1D engine simulation tools are widely used to model the combustion and gas flow processes in a four-stroke spark ignited engine. LES software represents a powerful tool for optimization of engine dynamic processes and parameters. The simulation and design of engines can drastically reduce time and costs in automotive industry. 1D advance systems are needed for an effective boosting of the engine. A mono cylindrical spark ignition engine was analyzed to determine the performance and general parameters.

Study of Inductive Sensors for Automotive Applications

There is an ever increasing demand for use of inductive speed sensors in a broad range of applications. They are used in typical applications such as cam and crank shaft position/speed and wheel and turbo shaft speed measurement. This paper describes the type of inductive sensor found on vehicles and the difficulties of detecting at low speeds. In the laboratory of Mechatronics an experimental device has been done to measure the speed using an inductive speed sensor. The experimental results are satisfactory and show the possibility of the inductive sensors to be used in automotive industry.

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.