FME Transactions 

About: FME Transactions is an academic journal published by Faculty of Agronomy in Čačak. The journal publishes majorly in the area(s): Machining & Surface roughness. It has an ISSN identifier of 1451-2092. It is also open access. Over the lifetime, 922 publications have been published receiving 6694 citations. The journal is also known as: Faculty of Mechanical Engineering Transactions.

Multi period disassembly-to-order of end of life product based on scheduling to maximize the profit in reverse logistic operation

Abstract: In recent era, the creation of electronic contraptions is expanding step by step, which leads to tremendous electronic waste. This is the condition drives as a result of the current individuals expecting new innovation in a brief time. This circumstance makes the manufacturers in a circumstance to create the new item in a brief time, so the current items need to either be disposed or dismantled. In this circumstance the manufactures wanted to re-manufacture the end-of-life (E-O-L) items to meet the component necessity in the new items production. In this sense in our previous work we exhibited a methodology to choose the optimal number of take back product, so that the aggregate expense needed for the reverse logistic (RL) can be lessened. In this paper, we exhibited a novel methodology for the RL operation of E-O-L items, in view of an optimal scheduling algorithm. In the previous work we have located the optimal number of take back E-O-L products for the disassembly-to-order (D-T-O), and this paper displayed the procedure to legitimately schedule the machines to disassemble the products, so that the aggregate time as well as the total cost needed for the RL operation can be diminished. In the proposed structure artificial bee colony (ABC) algorithm is utilized. The proposed framework drives the preferred performance over the existing scheduling algorithms.

A review of explicit approximations of Colebrook's equation

Abstract: The most common explicit correlations for estimation of the friction factor in rough and smooth pipes are reviewed in this paper. Comparison of any friction factor equation with the Colebrook's equation was expressed trough the mean relative error, the maximal positive error, the maximal negative error, correlation ratio and standard deviation. The statistical comparison of different equations was also carried out using the 'Model selection criterion' and 'Akaike Information Criterion'. It was found that the equation of Zigrang and Sylvester provides the most accurate value of friction factor, and that Haaland's equation is most suitable for hand calculations.

Global impact of friction on energy consumption, economy and environment

Abstract: Energy is a key resource for our society today and will be crucial for our sustainability in the future. A considerable amount of energy is consumed to overcome friction, especially in the transportation, industrial, and power-generation sectors, and major economic losses are also due to wear of products and components and their replacement. Jost [1] concluded that studies carried out in several industrial countries indicate that 1.0 to 1.4 % of the gross national product can be saved by introducing better tribological practices, requiring investment in research and development at a rate of one in 50 of the savings obtainable. Today, considerable effort is being devoted to producing increasingly more energy efficient vehicles and machines, not only for economic reasons, but also to help meet the requirements for reduced CO2 emissions arising from the Kyoto Protocol on climate change. A major source of CO2 emissions are cars and trucks. Transportation consumes about 20 % of the global primary energy and accounts for about 18 % of the total anthropogenic greenhouse gas emissions [2,3]. In this paper we summarize our studies for calculating the global energy consumption due to friction and potential savings from friction reduction in transportation and in industry [4-6]. We first focused our attention on passenger cars for two reasons: passenger cars form a major consumer of energy and also generate a considerable part of the greenhouse gas emissions. The other reason was that the energy use in passenger cars has been largely studied on the systemto-component level. The present study is based on the current set of technical solutions for passenger cars, trucks, buses and advanced industrial processing machinery here represented by paper machines, while the effects of expected changes, future trends, and predictions in this set are not included.

An analytical method for the measurement of energy systems sustainability in urban areas

Abstract: The assessment of sustainability of the city energy systems is an important topic in the current research and forecasting of development of various countries. In this paper the new approach for the measurement of the sustainability of the city energy system is introduced. It is based on the prediction of the future energy needs within the city consuming sectors, on the specification of scenarios of the city energy system development and on the validation of scenarios with a multicriteria decision method. The defined scenarios take into account utilization of different energy sources, exploitation of existing energy plants and infrastructure and building of new plants. The sustainability criteria are described with the new unique set of economical, social and ecological indicators. The new approach is applied to the forecasting of the sustainable development of the energy system of the city of Belgrade.

Numerical and Analytical Investigation of Vertical Axis Wind Turbine

Abstract: The majority of wind turbine research is focused on accurately efficiency prediction. This work highlights the progress made in the development of aerodynamic models for studying Vertical-Axis Wind Turbines (VAWTs) with particular emphasis on stream tube approach. Numerical and analytical investigation is conducted on straight blade fixed pitch VAWT using NACA0012 airfoil as a blade profile to assess its performance. Numerical simulation is done for two-dimensional unsteady flow around the same VAWT model using ANSYS FLUENT by solving Reynolds- averaged Navier-Stokes equations. Finally, comparison of the analytical results using double multiple stream tube (DMST) model with computational fluid dynamics (CFD) simulation has been done. Both the CFD and DMST results have shown minimum and/or negative torque and performance at lower tip speed ratios for the modeled turbine, which implies the inability of NACA0012 to self start.