Slobodan Tašin - Academia.edu (original) (raw)
Papers by Slobodan Tašin
DOAJ (DOAJ: Directory of Open Access Journals), 2010
Универзитет у Новом Саду, Nov 24, 2016
In this paper continuous measuring of viscosity of sucrose solution on the evaporator is analyzed... more In this paper continuous measuring of viscosity of sucrose solution on the evaporator is analyzed. The aim was to consider the possibilities of applying Hagen-Poiseuille equations on the existing straight section of the pipeline of the evaporator. Experimental testing was conducted in real conditions on the existing evaporator. The aim was to calibrate the measuring system, and to obtain a mathematical model (dependence of the conversion factor K, the concentration of sugar in sucrose C, temperature of the solution t and hydraulic parameter of measurement system Δp/Q. The obtained mathematical model is validated with literature data. It was found that for each pair of values of sugar concentration in sucrose solution C and solution temperature t, at a given value of hydraulic parameter Δp/Q>(Δp/Q) lim , the difference between the measurement data and the data obtained by the mathematical model was negligible. Since the flow of the evaporator is regulated, it is possible to adjust the hydraulic parameter of measurement system Δp/Q. In this way, it was confirmed that the proposed technical solution can be successfully and reliably used for continuous measurement of viscosity of sucrose solutions. Compared to the conventional capillary viscometer, the proposed technical solution is much cheaper. Like with the capillary viscometer, space is still needed to accommodate the measuring system. The proposed technical solution of the measurement system requires a long process of calibration on the evaporator in the real terms.
SSRN Electronic Journal, 2021
Journal of Applied Fluid Mechanics, 2021
Importance of accurate fluid flow measurement in industry is crucial especially today with rising... more Importance of accurate fluid flow measurement in industry is crucial especially today with rising energy prices. There is no ideal measuring instrument due to numerous errors occurring during process of physical quantities measurement but also due to specific requirements certain instruments have like fluid type, installation requirements, measuring range etc. Each measuring instrument has its pros and cons represented in accuracy, repeatability, resolution, etc. Conventional single-hole orifice (SHO) flow meter is a very popular differential-pressure-based measuring instrument, but it has certain disadvantages that can be overcame by multi-holes orifice (MHO) flow meter. Having this in mind, the aim of this paper is to help gain more information about MHO flow meters. Both SHO and MHO gas (air) flow meters with same total orifice area and the pipe area ratio β were numerically studied and compared using computational fluid dynamics (CFD). Simulation results of 16 different orifices with four different β (0.5, 0.55, 0.6 and 0.7) were analysed through pressure drop and singular pressure loss coefficient. Standard k-ε turbulence model was used as a turbulence model. Beside singular pressure loss coefficient, pressure recovery as well as axial velocity for both the SHO and MHO were reported. Results showed lower (better) singular pressure loss coefficient and pressure drop as well as quicker pressure recovery in favour of the MHO flow meters. Also, centreline axial velocity results were lower for MHO compared to corresponding SHO. CFD simulation results were verified by experimental results where air was used as a working fluid. The influence of geometrical and flow parameters on singular pressure loss coefficient was also reported and results showed that MHO hole distribution did not have significant influence on singular pressure loss coefficient.
Advances in Mechanical Engineering, May 1, 2022
Energy and Buildings, 2015
Abstract The damper used for the control of airflow in heating, ventilation and air conditioning ... more Abstract The damper used for the control of airflow in heating, ventilation and air conditioning systems can constructively be adapted to measure the air velocity with its moment characteristic. It is a device that indirectly determines the air velocity by measuring the position of the blades and the air stream moment acting on it. The subject of this paper is energy consumption of the air torque position damper depending on its structure. The aim is to compare the energy consumption of four possible types of dampers with non-cascading blades: with one blade, with two cross-guided blades, with two parallels-guided blades and with two blades, one of which is a measuring blade and the other remains fixed in horizontal position. The case when there is a straight section of a duct both in front of and behind the damper was considered. Adequacy of the existing mathematical model and energy consumption for all four types of dampers was determined experimentally. It was found that the damper with two blades of which one is a measuring blade and other remains fixed in horizontal position had minimal energy consumption.
Advances in Mechanical Engineering
Nowadays, with rising energy prices, energy efficiency is playing an important role in all indust... more Nowadays, with rising energy prices, energy efficiency is playing an important role in all industries. Differential pressure-based measuring instruments are still widely used instruments with orifice flow meters being the most popular ones. Due to its simplicity, reliability, and ease of maintenance, orifice flow meters are very common measuring instruments in many industries. As these instruments are differential pressure-based instruments, they are increasing energy costs due to increased pressure loss. Conventional single-hole orifice (SHO) flow meters have many advantages but also some disadvantages that are affecting energy efficiency. These disadvantages like higher pressure difference, slower pressure recovery, lower discharge coefficient can be overcome by multi-hole orifice (MHO) flow meters. Computational fluid dynamics (CFD) simulations were used to study energy consumption of both SHO and MHO with four different β parameters. Results showed MHO to be more energy efficien...
Starting of an electric motor drive with hydrodynamic coupling is a transient operation regime be... more Starting of an electric motor drive with hydrodynamic coupling is a transient operation regime beginning with the start of a driving electric motor and lasting to its steady-state operation. It is important to explore this process as it can be used as the basis for evaluation of relevant parameters used for the choice of the motor and power transmission elements. This includes the calculation of starting intervals of a driving motor (it has to be short enough) and an output operating device (it has to be long enough), determination of the thermal and mechanical loading of driving mechanism elements, etc. The paper contains, as an example, a proposition for a short and sufficiently exact calculation procedure of a hydrodynamic coupling starting regime.
The scope of this paper is a thermodynamic process in mixing chamber of supersonic steam-water in... more The scope of this paper is a thermodynamic process in mixing chamber of supersonic steam-water injector. This injector is actually a simple heat pump due to the fact that it can substitute a pump and heat exchanger. Initial energy source of supersonic steam-water injector is usually a small amount of steam with low thermal properties which could not be used for more demanding utilities. The aim of wider investigation is to build up a relatively high pressure of hot water at the outlet of mixing chamber during a “forced condensation” of steam which is in the cold water surrounding in mixing chamber. Forced condensation, which is described by modified Mollier diagram of wet steam, reveals clearer picture of this complex flow process. The paper emphasizes Mach number (M=v/c) which, largely, represents flow process in mixing chamber. Sound velocity (c) is a physical property of fluid which is a function of different parameters (T, ρ, η, pipeline elasticity, solid impurities, gas bubbles...
In this paper continuous measuring of viscosity of sucrose solution on the evaporator is analyzed... more In this paper continuous measuring of viscosity of sucrose solution on the evaporator is analyzed. The aim was to consider the possibilities of applying Hagen-Poiseuille equations on the existing straight section of the pipeline of the evaporator. Experimental testing was conducted in real conditions on the existing evaporator. The aim was to calibrate the measuring system, and to obtain a mathematical model (dependence of the conversion factor K, the concentration of sugar in sucrose C, temperature of the solution t and hydraulic parameter of measurement system Δp/Q. The obtained mathematical model is validated with literature data. It was found that for each pair of values of sugar concentration in sucrose solution C and solution temperature t, at a given value of hydraulic parameter Δp/Q>(Δp/Q)lim, the difference between the measurement data and the data obtained by the mathematical model was negligible. Since the flow of the evaporator is regulated, it is possible to adjust t...
Flow Measurement and Instrumentation
Flow Measurement and Instrumentation
Energy and Buildings, 2015
DOAJ (DOAJ: Directory of Open Access Journals), 2010
Универзитет у Новом Саду, Nov 24, 2016
In this paper continuous measuring of viscosity of sucrose solution on the evaporator is analyzed... more In this paper continuous measuring of viscosity of sucrose solution on the evaporator is analyzed. The aim was to consider the possibilities of applying Hagen-Poiseuille equations on the existing straight section of the pipeline of the evaporator. Experimental testing was conducted in real conditions on the existing evaporator. The aim was to calibrate the measuring system, and to obtain a mathematical model (dependence of the conversion factor K, the concentration of sugar in sucrose C, temperature of the solution t and hydraulic parameter of measurement system Δp/Q. The obtained mathematical model is validated with literature data. It was found that for each pair of values of sugar concentration in sucrose solution C and solution temperature t, at a given value of hydraulic parameter Δp/Q>(Δp/Q) lim , the difference between the measurement data and the data obtained by the mathematical model was negligible. Since the flow of the evaporator is regulated, it is possible to adjust the hydraulic parameter of measurement system Δp/Q. In this way, it was confirmed that the proposed technical solution can be successfully and reliably used for continuous measurement of viscosity of sucrose solutions. Compared to the conventional capillary viscometer, the proposed technical solution is much cheaper. Like with the capillary viscometer, space is still needed to accommodate the measuring system. The proposed technical solution of the measurement system requires a long process of calibration on the evaporator in the real terms.
SSRN Electronic Journal, 2021
Journal of Applied Fluid Mechanics, 2021
Importance of accurate fluid flow measurement in industry is crucial especially today with rising... more Importance of accurate fluid flow measurement in industry is crucial especially today with rising energy prices. There is no ideal measuring instrument due to numerous errors occurring during process of physical quantities measurement but also due to specific requirements certain instruments have like fluid type, installation requirements, measuring range etc. Each measuring instrument has its pros and cons represented in accuracy, repeatability, resolution, etc. Conventional single-hole orifice (SHO) flow meter is a very popular differential-pressure-based measuring instrument, but it has certain disadvantages that can be overcame by multi-holes orifice (MHO) flow meter. Having this in mind, the aim of this paper is to help gain more information about MHO flow meters. Both SHO and MHO gas (air) flow meters with same total orifice area and the pipe area ratio β were numerically studied and compared using computational fluid dynamics (CFD). Simulation results of 16 different orifices with four different β (0.5, 0.55, 0.6 and 0.7) were analysed through pressure drop and singular pressure loss coefficient. Standard k-ε turbulence model was used as a turbulence model. Beside singular pressure loss coefficient, pressure recovery as well as axial velocity for both the SHO and MHO were reported. Results showed lower (better) singular pressure loss coefficient and pressure drop as well as quicker pressure recovery in favour of the MHO flow meters. Also, centreline axial velocity results were lower for MHO compared to corresponding SHO. CFD simulation results were verified by experimental results where air was used as a working fluid. The influence of geometrical and flow parameters on singular pressure loss coefficient was also reported and results showed that MHO hole distribution did not have significant influence on singular pressure loss coefficient.
Advances in Mechanical Engineering, May 1, 2022
Energy and Buildings, 2015
Abstract The damper used for the control of airflow in heating, ventilation and air conditioning ... more Abstract The damper used for the control of airflow in heating, ventilation and air conditioning systems can constructively be adapted to measure the air velocity with its moment characteristic. It is a device that indirectly determines the air velocity by measuring the position of the blades and the air stream moment acting on it. The subject of this paper is energy consumption of the air torque position damper depending on its structure. The aim is to compare the energy consumption of four possible types of dampers with non-cascading blades: with one blade, with two cross-guided blades, with two parallels-guided blades and with two blades, one of which is a measuring blade and the other remains fixed in horizontal position. The case when there is a straight section of a duct both in front of and behind the damper was considered. Adequacy of the existing mathematical model and energy consumption for all four types of dampers was determined experimentally. It was found that the damper with two blades of which one is a measuring blade and other remains fixed in horizontal position had minimal energy consumption.
Advances in Mechanical Engineering
Nowadays, with rising energy prices, energy efficiency is playing an important role in all indust... more Nowadays, with rising energy prices, energy efficiency is playing an important role in all industries. Differential pressure-based measuring instruments are still widely used instruments with orifice flow meters being the most popular ones. Due to its simplicity, reliability, and ease of maintenance, orifice flow meters are very common measuring instruments in many industries. As these instruments are differential pressure-based instruments, they are increasing energy costs due to increased pressure loss. Conventional single-hole orifice (SHO) flow meters have many advantages but also some disadvantages that are affecting energy efficiency. These disadvantages like higher pressure difference, slower pressure recovery, lower discharge coefficient can be overcome by multi-hole orifice (MHO) flow meters. Computational fluid dynamics (CFD) simulations were used to study energy consumption of both SHO and MHO with four different β parameters. Results showed MHO to be more energy efficien...
Starting of an electric motor drive with hydrodynamic coupling is a transient operation regime be... more Starting of an electric motor drive with hydrodynamic coupling is a transient operation regime beginning with the start of a driving electric motor and lasting to its steady-state operation. It is important to explore this process as it can be used as the basis for evaluation of relevant parameters used for the choice of the motor and power transmission elements. This includes the calculation of starting intervals of a driving motor (it has to be short enough) and an output operating device (it has to be long enough), determination of the thermal and mechanical loading of driving mechanism elements, etc. The paper contains, as an example, a proposition for a short and sufficiently exact calculation procedure of a hydrodynamic coupling starting regime.
The scope of this paper is a thermodynamic process in mixing chamber of supersonic steam-water in... more The scope of this paper is a thermodynamic process in mixing chamber of supersonic steam-water injector. This injector is actually a simple heat pump due to the fact that it can substitute a pump and heat exchanger. Initial energy source of supersonic steam-water injector is usually a small amount of steam with low thermal properties which could not be used for more demanding utilities. The aim of wider investigation is to build up a relatively high pressure of hot water at the outlet of mixing chamber during a “forced condensation” of steam which is in the cold water surrounding in mixing chamber. Forced condensation, which is described by modified Mollier diagram of wet steam, reveals clearer picture of this complex flow process. The paper emphasizes Mach number (M=v/c) which, largely, represents flow process in mixing chamber. Sound velocity (c) is a physical property of fluid which is a function of different parameters (T, ρ, η, pipeline elasticity, solid impurities, gas bubbles...
In this paper continuous measuring of viscosity of sucrose solution on the evaporator is analyzed... more In this paper continuous measuring of viscosity of sucrose solution on the evaporator is analyzed. The aim was to consider the possibilities of applying Hagen-Poiseuille equations on the existing straight section of the pipeline of the evaporator. Experimental testing was conducted in real conditions on the existing evaporator. The aim was to calibrate the measuring system, and to obtain a mathematical model (dependence of the conversion factor K, the concentration of sugar in sucrose C, temperature of the solution t and hydraulic parameter of measurement system Δp/Q. The obtained mathematical model is validated with literature data. It was found that for each pair of values of sugar concentration in sucrose solution C and solution temperature t, at a given value of hydraulic parameter Δp/Q>(Δp/Q)lim, the difference between the measurement data and the data obtained by the mathematical model was negligible. Since the flow of the evaporator is regulated, it is possible to adjust t...
Flow Measurement and Instrumentation
Flow Measurement and Instrumentation
Energy and Buildings, 2015