Miloš Milošević

FUNCTION K - AS A LINK BETWEEN FUEL FLOW VELOCITY AND FUEL PRESSURE, DEPENDING ON THE TYPE OF FUEL

Regarding the application of vegetable oil based fuels in diesel engines, it is necessary to fully examine and understand the processes which take place in fuel delivery systems, namely, the processes of injection, mixture formation and combustion as well as emission characteristics. The paper provides an analysis of fuel flow in high pressure tubes of the fuel injection system, with the aim of determining function K as a link between fuel flow velocity and fuel pressure, and observing the influence of certain physical characteristics of the fuel upon the given function. The analysis presents the speed of sound and density, as fuel characteristics which affect the K function. The paper determines the speed of sound, density and bulk modulus for four fuels (pure rapeseed oil RO, biodiesel B100, a mixture of biodiesel and diesel B50, and diesel D), and forms appropriate K functions for each fuel in the pressure range from the atmospheric one to 1600 bar.

REMOTE CONTROL OF THE MECHATRONIC REDESIGNED SLIDER-CRANK MECHANISM IN SERVICE

Slider-crank mechanisms are used in many machines where there is a need to transform rotary motion into translation, and vice versa. Implementation of the control into a mechanical assembly of the slider-crank mechanism offers a wide range of applications of such controlled mechanism in mechatronic systems. This paper shows an example of the remote control of the angular velocity of the crank in a mechatronic redesigned slider-crank mechanism in order to achieve the desired motion of the slider. The remote control is achieved over the Internet connection and the appropriate software which is executed in the user’s internet browser. The aim of this paper is to present the applied control algorithm as well as to explain advantages of the possibility to remotely run a mechatronic redesigned slider-crank mechanism in service. This is done through an example of using a controlled slider-crank mechanism in a remote laboratory experiment.

DETERMINATION OF RESIDUAL STRESS IN THE RAIL WHEEL DURING QUENCHING PROCESS BY FEM SIMULATION

Residual stresses of the rail wheels are influenced by heat treatment during the manufacturing process. The quenching process during the manufacturing results in the residual stresses within the rail wheel that may be dangerous for the rail wheel during its operation. Determination of the residual stress in the rail wheel is important for understanding the damage mechanisms and their influence on the proper work of rail wheels. This paper presents a method for determining the residual stresses in the rail wheel during the quenching process by using the directly coupled thermal-structural analysis in ANSYS software.