Tag Archives: simulation.

481–490 A. Kešner, R. Chotěborský, M. Linda and M. Hromasová
Methodology of the stress detemination in the tool module during the work of the agriculture machine
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Methodology of the stress detemination in the tool module during the work of the agriculture machine

A. Kešner¹*, R. Chotěborský¹, M. Linda² and M. Hromasová²

¹Czech University of Life Sciences Prague, Facult of Engineering, Department of Material Science and Manufacturing Technology, Kamýcká 129, CZ165 21 Prague, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of Eletrical Engineering and Automation, Kamýcká 129, CZ165 21 Prague, Czech Republic
*Correspondence: kesner@tf.czu.cz

Abstract:

Machine construction is designed using by mathematical models. The frame is a fundamental part of an agricultural soil cultivation machine so that forces were transferred during transport and machine work to frame. The stress in the machine frame is important to know for the best frame design of the machine. The mathematical model included measured strain can able to design or detect deficiencies on the machine frame. Due to the transfer of forces from the tools, stress is created in the machine frame. High requirements are placed on the determination of boundary conditions for mathematical models in agricultural machinery. Various types, sizes and equipment of agricultural tools significantly affect the transfer of drought force to the machine. The direction and magnitude of the forces, that are caused by agricultural tools, it is important to find out. Ansys mechanical solver have been used to determination strain like response of frame from chisel module. The results can be used as a boundary condition for mathematical models.

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237-244 M. Zajicek, and P. Kic
Heating of large agricultural and industrial buildings
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Heating of large agricultural and industrial buildings

M. Zajicek¹,* and P. Kic²

¹Institute of Information Theory and Automation, The Academy of Science of The Czech Republic, v.v.i.; *Correspondence: zajicek@utia.cas.cz 2Czech University of Life Sciences Prague, Faculty of Engineering, Czech Republic

Abstract:

This paper presents the results of the simulation calculations used in the selection and design of an appropriate method of heating of large buildings for agricultural or industrial purposes. These halls are characterized by a large built-up area, large room height and high consumption of energy for heating. The aim of the simulation calculation was to find a way of heating, which leads to a reduction in energy consumption while maintaining the required thermal comfort of indoor environment. The calculations were performed using the CFD software ANSYS-Fluent. For comparison of variants, a 3D model was used, including a heat source, natural convection and heat transfer through surrounding structures. The results of the thermal comfort of the working environment in the level of people or the growing zone of plants or the storage space for goods were mainly studied. The second area of interior space, especially important in terms of heat losses, is the level of the ceiling. The results of the calculations provide a detailed analysis of the vertical temperature profiles and the effect of the surrounding walls surface temperature on the thermal state of an indoor environment. The created model was verified according to the results of experiments in large buildings equipped with different heating systems. Based on the results of the simulation calculations and according to the results of experimental measurements, radiant heating method seems to be the suitable heating system solution for studied types of buildings.

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157-166 V. Mikita, J. Roots and J. Olt
Simulation model of the combustion processes of a diesel engine
Abstract |
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Simulation model of the combustion processes of a diesel engine

V. Mikita¹, J. Roots² and J. Olt¹

¹Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56,
EE51014, Tartu, Estonia; e-mail: villu.mikita@emu.ee,
²Institute of Economics and Social Sciences, Estonian University of Life Sciences,
Kreutzwaldi 56, EE51014 Tartu, Estonia

Abstract:

It is foreseen that in the near future in Estonia there will be growth in the consumption of alternative liquid fuels in internal combustion engines. The main share of it will be formed by the local raw material based diesel fuel and ethanol. In connection with this, the choice of fuels and the variety of their qualitative characteristics in filling stations will grow. This kind of situation will give rise to the necessity of creating new quality assessment methods which should be reliable, efficient and economical. There may be several assessment methods for taking fuel samples. Drivers consider the fuel quality assessment express methods especially valuable. Working out a new method like that is at present also supported by the electronic control system of the engine and the use of digital diagnostic devices. Creating and implementing the fuel quality assessment express method requires a considerable amount of effort. It includes the evaluation and prognosis of the fuels physical and chemical parameters, designing the simulation models of the engine combustion process pressure and temperature and carrying out the control testing.

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