Ilie Dumitru

Modeling the Vehicle-Bicycle Collision - The Analysis of the Projection Distance and Acceleration at the Cyclist's Head

The ever-growing demand for transportation and the need to carry both people and goods has led to increased congestions of road traffic networks. Subsequently, the main negative effect is the multiplication of serious road accidents. Of the total number of serious road accidents, a significant increase has been registered among cyclists, with 13.9% in 2014 of total vehicles involved in traffic accidents, compared to 6.6% in 2010. The present paper underpins a close analysis of the kinematic and dynamic parameters in the event of a vehicle - bicycle – cyclist assembly – collision type. To study the vehicle-bicycle-collision type, we carried out a comparative analysis with regard to the distance the cyclist is thrown away following the collision, the speed variation of the vehicle and of the bicycle, and the speed variation in the cyclist’s head area, as well as the variation of the acceleration recorded on the vehicle, the bicycle and the cyclist’s head area. Hence, we modelled and simulated the vehicle – bicycle collision for two distinct instances, i.e. a frontal vehicle – rear bicycle collision and a frontal vehicle - frontal bicycle collision.

Experimental and theoretical study of friction torque from radial ball bearings

In this paper it is presented a numerical simulation and an experimental study of total friction torque from radial ball bearings. For this purpose it is conceived a virtual CAD model of the experimental test bench for bearing friction torque measurement. The virtual model it is used for numerical simulation in ADAMS software, that allows dynamic study of multi-body systems and in particularly with facility Adams Machinery of dynamic behavior of machine parts. It is manufactured an experimental prototype of the test bench for radial ball bearings friction torque measurement. In order to measure the friction torque of the tested bearings it is used an equal resistance elastic beam element, with strain gauge transducer to measure bending deformations. The actuation electric motor of the bench has the shaft mounted on two bearings and the motor housing is fixed to the free side of the elastic beam, which is bended by a force proportional with the total friction torque. The beam elastic element with strain gauge transducer is calibrated in order to measure the force occurred. Experimental determination of the friction torque is made for several progressive radial loads. It is established the correlation from the friction torque and bearing radial load. The bench allows testing of several types and dimensions of radial bearings, in order to establish the bearing durability and of total friction torque.

Mathematical Algorithm for Calculating the Total Traffic Lights Cycle in Junctions

Because the current development of cities and increased motorization, mobility in the city/metropolis suffers greatly. In these conditions the development of new traffic control methods in junctions is important. Conditioned by the current technical development, control methods are developed more in the area of mathematical algorithms which can be used to control the traffic equipment’s with a new efficiency. So the new intelligent traffic control modes involve the use of even more efficient and faster mathematical algorithms.

Determination of Kinematic and Dynamic Behavior in the Driver’s Skull upon the Impact with the Steering Wheel

At European level, one of the main causes of death rates is generated by severe injuries following traffic accidents. The most serious consequences of traffic accidents result from lesions in the head.

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.

Adaptive Traffic Signal Control on a National Road Intersection

Adaptive traffic signal control is the process by which the timing of a traffic signal is continuously adjusted based on the changing arrival patterns of vehicles at an intersection, usually with the goal of optimizing a given measure of effectiveness. In this paper a traffic signal program is developed in which the characteristics of a traffic signal cycle are optimized at the conclusion of every phase based on the arrival times of vehicles to an intersection, using stopped delay as the measure of effectiveness. The methodology which leads to the signal plan is shown to provide improvement in performance for a number of intersection configurations and traffic regimes over traditional forms of traffic signal control.

The Influence of the Working Regime of Oscillations Produced by an Electrovibrator on the Sorting of Materials

In order to be used as food supplements, materials (medicinal and aromatic plants, other materials containing active principles, etc.) need to be chopped and sorted by size, depending on the field of use: herbal tea, suspensions, tinctures, etc. The paper presents the results of research on the sorting process of some materials containing active principles (yarrow, alfalfa and willow bark) using a sorting machine provided with 2 electro vibrators fitted on each side of the framework within which 3 sieves with a mesh size of: 2.15, 4 and 8 mm are fitted, changing the oscillation regime of the sieves by adjusting the angle of the electro vibrators, in order to identify the optimal sorting regime.

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.

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.

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.